(Meth)acrylic acid ester copolymer and curable composition thereof

Abstract

The present invention provides a (meth)acrylic acid ester-based copolymer (B) having a reactive silicon group indicated in general formula (1). The monomer components constituting said copolymer include a (meth)acrylic acid ester (b1), a (meth)acrylic acid ester-based polymer (b2) having more than one (meth)acryloyl group per molecule, and a chain transfer agent (b3) having a mercapto group. The monomer components further include a monomer (b4) that has a reactive silicon group and a polymerizable unsaturated group, and / or the chain transfer agent (b3) having a mercapto group further has a reactive silicon group. General formula (1): -SiR5 cX3-c (In the formula, R5 represents a substituted or unsubstituted hydrocarbon group having 1-20 carbon atoms. X represents a hydroxyl group or a hydrolyzable group. c represents 0 or 1.)

Description

[Technical Field]

[0001] The present invention relates to a (meth)acrylic acid ester copolymer having a reactive silicon group, a method for producing the same, and a curable composition containing the copolymer. [Background technology]

[0002] Organic polymers that have hydroxyl or hydrolyzable groups on the silicon atom and can form siloxane bonds through hydrolysis and condensation reactions (hereinafter referred to as "reactive silicon groups") react with moisture even at room temperature. It is known that such organic polymers can be crosslinked by the siloxane condensation reaction of the reactive silicon groups to produce rubber-like cured products.

[0003] Among these organic polymers, polyoxyalkylene polymers having reactive silicon groups have a relatively low viscosity, which makes them easy to work with when preparing and using blended compositions. Furthermore, the resulting cured products have a good balance of mechanical properties, weather resistance, dynamic durability, and other performance characteristics, making them widely used in applications such as sealants, adhesives, and paints (see Patent Document 1).

[0004] In order to improve the weather resistance and adhesiveness of polyoxyalkylene polymers having reactive silicon groups, a curable composition containing a reactive silicon group-containing polyoxyalkylene polymer in combination with a reactive silicon group-containing (meth)acrylic acid ester polymer is known (see Patent Document 2). This curable composition is used as a highly weather-resistant sealant or industrial adhesive.

[0005] On the other hand, reactive silicon group-containing (meth)acrylic acid ester polymers have been reported that contain, as constituent monomers, a monomer having a reactive silicon group and a polymerizable unsaturated group, and a macromonomer having a polymerizable unsaturated group (see Patent Document 3). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 52-73998 [Patent Document 2] Japanese Unexamined Patent Publication No. 59-122541 [Patent Document 3] International Publication No. 2017 / 057719 Summary of the Invention [Problem to be solved by the invention]

[0007] It is desirable that the polymer having a reactive silicon group has a narrow molecular weight distribution and low viscosity so as to be easy to handle before curing, and yet exhibits good physical properties after curing.

[0008] In view of the above-mentioned current situation, an object of the present invention is to provide a reactive silicon group-containing (meth)acrylic acid ester copolymer that has a narrow molecular weight distribution and low viscosity, yet exhibits good physical properties after curing, and a curable composition containing the same. [Means for solving the problem]

[0009] As a result of extensive research to solve the above-mentioned problems, the present inventors have found that the above-mentioned problems can be solved by using a specific monomer and a chain transfer agent as monomer components constituting a reactive silicon group-containing (meth)acrylic acid ester-based polymer, and have thus completed the present invention.

[0010] That is, the first invention relates to a (meth)acrylic acid ester-based copolymer (B) having a reactive silicon group represented by general formula (1), wherein the monomer components constituting the copolymer contain a (meth)acrylic acid ester (b1), a (meth)acrylic acid ester-based polymer (b2) having more than one (meth)acryloyl group in the molecule, and a chain transfer agent (b3) having a mercapto group, and the monomer components further contain a monomer (b4) having a reactive silicon group and a polymerizable unsaturated group, and / or the chain transfer agent (b3) having a mercapto group further contains a reactive silicon group. -SiR5 c X 3-c (1) (In the formula, R 5 is a substituted or unsubstituted hydrocarbon group having 1 to 20 carbon atoms. X represents a hydroxyl group or a hydrolyzable group. c represents 0 or 1. Preferably, the (meth)acrylic acid ester polymer (b2) accounts for 0.2 mol % or more and 5.0 mol % or less of the monomer component. Preferably, the chain transfer agent (b3) having a mercapto group accounts for 0.4 mol % or more and 15 mol % or less of the monomer component. Preferably, the number average molecular weight of the (meth)acrylic acid ester polymer (b2) is 500 or more and 50,000 or less. Preferably, the weight average molecular weight of the (meth)acrylic acid ester copolymer (B) is 80,000 or less. Preferably, the molecular weight distribution of the (meth)acrylic acid ester copolymer (B) is 3.0 or more and 11.0 or less. Preferably, the molar ratio of the (meth)acrylic acid ester polymer (b2) to the chain transfer agent (b3) having a mercapto group is 0.12 or more. The second aspect of the present invention relates to a (meth)acrylic acid ester copolymer (B) having a reactive silicon group represented by general formula (1), wherein the copolymer comprises a structure in which two first molecular chains are bonded via one second molecular chain, and both ends of the second molecular chain are bonded to non-terminal portions of the first molecular chain, and the first molecular chain and the second molecular chain are each composed of molecular chains of a (meth)acrylic acid ester copolymer, and the reactive silicon group is bonded to the first molecular chain, and the first molecular chain has at one end a structure represented by -SR (where S represents a sulfur atom and R represents a hydrocarbon group which may have the reactive silicon group). Preferably, the monomer component constituting the first molecular chain contains at least one monomer selected from the group consisting of methacrylic acid ester, isobornyl acrylate, dicyclopentenyl acrylate, and dicyclopentanyl acrylate, and the monomer component constituting the second molecular chain contains an acrylic acid ester. More preferably, the proportion of at least one monomer selected from the group consisting of methacrylic acid esters, isobornyl acrylate, dicyclopentenyl acrylate, and dicyclopentanyl acrylate among the monomer components constituting the first molecular chain is 60% by weight or more, and the proportion of acrylic acid esters among the monomer components constituting the second molecular chain is 60% by weight or more. Preferably, the sulfur atom concentration in the (meth)acrylic acid ester copolymer (B) is 700 ppm or more and 20,000 ppm or less. The third aspect of the present invention relates to a curable composition containing the (meth)acrylic acid ester copolymer (B). The curable composition may further contain a polyoxyalkylene polymer (A) having a reactive silicon group represented by general formula (1). Preferably, the polyoxyalkylene polymer (A) is a compound represented by the general formula (2): [ka] (In the formula, R 1 ,R 3 are each independently a divalent linking group having 1 to 6 carbon atoms, and R 1 ,R 3 The atom bonded to each carbon atom adjacent to R is either carbon, oxygen, or nitrogen. 2 ,R 4 are each independently hydrogen or a hydrocarbon group having 1 to 10 carbon atoms. n is an integer of 1 to 10. R 5 is a substituted or unsubstituted hydrocarbon group having 1 to 20 carbon atoms. X is a hydroxyl group or a hydrolyzable group. c is 0 or 1. It has a terminal structure represented by the following formula: A fourth aspect of the present invention relates to a cured product of the curable composition. The fifth aspect of the present invention relates to a method for producing a (meth)acrylic acid ester copolymer (B) having a reactive silicon group represented by general formula (1), comprising a step of copolymerizing monomer components, wherein the monomer components contain a (meth)acrylic acid ester (b1), a (meth)acrylic acid ester polymer (b2) having more than one (meth)acryloyl group in the molecule, and a chain transfer agent (b3) having a mercapto group, and the monomer components further contain a monomer (b4) having a reactive silicon group and a polymerizable unsaturated group, and / or the chain transfer agent (b3) having a mercapto group further contains a reactive silicon group. [Effects of the Invention]

[0011] According to the present invention, it is possible to provide a reactive silicon group-containing (meth)acrylic acid ester copolymer that has a narrow molecular weight distribution and low viscosity, yet exhibits good physical properties (e.g., elongation, strength, etc.) after curing, and a curable composition containing the same. The reactive silicon group-containing (meth)acrylic acid ester copolymer according to the present invention includes a block copolymer, and can have a relatively low viscosity even when it has a narrow molecular weight distribution and a high average molecular weight. The reactive silicon group-containing (meth)acrylic acid ester copolymer of the present invention can be combined with a reactive silicon group-containing polyoxyalkylene polymer to form a curable composition, which can give a cured product with high tensile strength and adhesive strength. The curable composition according to a preferred embodiment of the present invention can exhibit high thixotropy, and therefore has good workability during application. DETAILED DESCRIPTION OF THE INVENTION

[0012] The following describes specific embodiments of the present invention, but the present invention is not limited to these embodiments.

[0013] <<Reactive silicon group-containing (meth)acrylic acid ester copolymer (B)>> The (meth)acrylic acid ester copolymer (B) has a reactive silicon group represented by general formula (1) at the molecular chain terminal and / or side chain (non-terminal site). -SiR 5 c X 3-c (1) (In the formula, R 5 is a substituted or unsubstituted hydrocarbon group having 1 to 20 carbon atoms. X represents a hydroxyl group or a hydrolyzable group. c represents 0 or 1.

[0014] R 5 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. 5 Specific examples of the 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 or an ethyl group.

[0015] Examples of X include a hydroxyl group, hydrogen, 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.

[0016] Specific examples of the reactive silicon group contained in the (meth)acrylic acid ester copolymer (B) 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. Trimethoxysilyl group and triethoxysilyl group are more preferred, and trimethoxysilyl group is even more preferred, because they give cured products with a high Young's modulus.

[0017] The reactive silicon group equivalent of the (meth)acrylic acid ester copolymer (B) is not particularly limited, but is preferably 0.06 mmol / g or more, more preferably 0.08 mmol / g or more, and even more preferably 0.1 mmol / g or more. The reactive silicon group equivalent is preferably 1.0 mmol / g or less, and from the viewpoint of suppressing a decrease in elongation of the cured product, is more preferably 0.5 mmol / g or less, and particularly preferably 0.3 mmol / g or less.

[0018] When a polyoxyalkylene polymer (A) and a (meth)acrylic acid ester copolymer (B) are used in combination, the reactive silicon group equivalent of the (meth)acrylic acid ester copolymer (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 more preferably 1.0 mmol / g or less in order to prevent a decrease in elongation of the cured product. To obtain a cured product with high rigidity and flexibility, the reactive silicon group equivalent is particularly preferably 0.5 mmol / g or more and 1.0 mmol / g or less.

[0019] The (meth)acrylic acid ester copolymer (B) is a polymer formed by copolymerizing monomer components containing at least a (meth)acrylic acid ester (b1), a (meth)acrylic acid ester polymer (b2) having more than one (meth)acryloyl group in the molecule, and a chain transfer agent (b3) having a mercapto group. In this application, "(meth)acrylic" means "acrylic and / or methacrylic."

[0020] The (meth)acrylic acid ester copolymer (B) will have reactive silicon groups when either or both of the following two conditions are satisfied: Condition 1: The monomer component further contains a monomer (b4) having a reactive silicon group and a polymerizable unsaturated group. Condition 2: The chain transfer agent (b3) having a mercapto group further has a reactive silicon group.

[0021] To obtain a cured product with high elongation, it is preferable that the number of reactive silicon groups introduced under condition 2 is greater than the number of reactive silicon groups introduced under condition 1. Specifically, the reactive silicon group equivalent introduced under condition 1 is preferably 0.01 mmol / g or more, more preferably 0.03 mmol / g or more, and even more preferably 0.05 mmol / g or more. The reactive silicon group equivalent is preferably 1.0 mmol / g or less, and more preferably 0.5 mmol / g or less. The reactive silicon group equivalent introduced under condition 2 is preferably 0.2 mmol / g or more, more preferably 0.3 mmol / g or more, and even more preferably 0.5 mmol / g or more. The reactive silicon group equivalent is preferably 1.5 mmol / g or less, and more preferably 1.0 mmol / g or less.

[0022] To obtain a cured product with high strength, it is preferable to introduce reactive silicon groups under both Condition 1 and Condition 2. Specifically, the reactive silicon group equivalent introduced under Condition 1 is preferably 0.1 mmol / g or more, more preferably 0.2 mmol / g or more, and even more preferably 0.3 mmol / g or more. Furthermore, the reactive silicon group equivalent is preferably 1.8 mmol / g or less, and more preferably 1.0 mmol / g or less. Furthermore, the reactive silicon group equivalent introduced under Condition 2 is preferably 0.1 mmol / g or more, more preferably 0.2 mmol / g or more, and even more preferably 0.3 mmol / g or more. Furthermore, the reactive silicon group equivalent is preferably 1.5 mmol / g or less, and more preferably 1.0 mmol / g or less.

[0023] ((Meth)acrylic acid ester (b1)) The (meth)acrylic acid ester (b1) is not particularly limited, and examples thereof include 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, nonyl (meth)acrylate, decyl (meth)acrylate, dodecyl (meth)acrylate, stearyl (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. Examples of such an acrylate include ethylene oxide adducts of (meth)acrylic acid, 2,2,2-trifluoroethyl (meth)acrylate, 3,3,3-trifluoropropyl (meth)acrylate, 3,3,4,4,4-pentafluorobutyl (meth)acrylate, 2-perfluoroethyl-2-perfluorobutylethyl (meth)acrylate, trifluoromethyl (meth)acrylate, perfluoroethyl (meth)acrylate, bis(trifluoromethyl)methyl (meth)acrylate, 2-trifluoromethyl-2-perfluoroethylethyl (meth)acrylate, 2-perfluorohexylethyl (meth)acrylate, 2-perfluorodecylethyl (meth)acrylate, 2-perfluorohexadecylethyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, chloroethyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, glycidyl (meth)acrylate, and 2-aminoethyl (meth)acrylate. One type may be used alone, or two or more types may be used in combination. The (meth)acrylic acid ester (b1) is preferably a (meth)acrylic acid alkyl ester.

[0024] Since a cured product with high strength can be obtained, the (meth)acrylic acid alkyl ester having an alkyl carbon number of 1 to 4 is preferably contained in an amount of 40% by weight or more, more preferably 45% by weight or more, and even more preferably 50% by weight or more, based on the total amount of monomer components constituting the (meth)acrylic acid ester-based copolymer (B).

[0025] In order to form a hard polymer, the (meth)acrylic acid ester (b1) preferably contains 60% by weight or more of at least one monomer selected from the group consisting of methacrylic acid esters, isobornyl acrylate, dicyclopentenyl acrylate, and dicyclopentanyl acrylate.

[0026] From the viewpoint of achieving both flexibility and high rigidity, the content of the (meth)acrylic acid ester (b1) is preferably 40% by weight or more, more preferably 45% by weight or more, even more preferably 50% by weight or more, even more preferably 55% by weight or more, and even more preferably 60% by weight or more, based on the total amount of monomer components constituting the (meth)acrylic acid ester copolymer (B). Furthermore, from the viewpoint of durable adhesion, the content of the (meth)acrylic acid ester (b1) is preferably 50% by weight or more, more preferably 55% by weight or more, and even more preferably 60% by weight or more, based on the total amount of monomer components constituting the (meth)acrylic acid ester copolymer (B). To ensure compatibility with the polyoxyalkylene polymer (A), the content is preferably 60% by weight or more, and even more preferably 70% by weight or more.

[0027] ((Meth)acrylic acid ester polymer (b2) having more than one (meth)acryloyl group in the molecule) The (meth)acrylic acid ester polymer (b2) is itself a polymer, but due to the presence of a (meth)acryloyl group, it can be copolymerized with other monomers, such as the (meth)acrylic acid ester (b1), and is one of the monomers constituting the (meth)acrylic acid ester copolymer (B). Furthermore, since the (meth)acrylic acid ester polymer (b2) has more than one (meth)acryloyl group per molecule, it can function as a so-called multifunctional macromonomer. The main chain skeleton (second molecular chain, described below) of the (meth)acrylic acid ester polymer (b2) can form a structure in the (meth)acrylic acid ester copolymer (B) that crosslinks two molecular chains (first molecular chains, described below) composed of polymers such as the (meth)acrylic acid ester (b1). Hereinafter, the (meth)acrylic acid ester polymer (b2) is also referred to as the multifunctional macromonomer (b2).

[0028] The main chain skeleton of the polyfunctional macromonomer (b2) is a (meth)acrylic acid ester polymer. The monomer constituting the main chain skeleton of the polyfunctional macromonomer (b2) is not particularly limited, and various (meth)acrylic monomers can be used. Examples of the (meth)acrylic monomer include (meth)acrylic acid, 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, nonyl (meth)acrylate, decyl (meth)acrylate, dodecyl (meth)acrylate, stearyl (meth)acrylate, phenyl (meth)acrylate, toluyl (meth)acrylate, benzyl (meth)acrylate, 2-methoxyethyl (meth)acrylate, 3-methoxybutyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, and 2-hydroxypropyl (meth)acrylate. , ethylene oxide adducts of (meth)acrylic acid, 2,2,2-trifluoroethyl (meth)acrylate, 3,3,3-trifluoropropyl (meth)acrylate, 3,3,4,4,4-pentafluorobutyl (meth)acrylate, 2-perfluoroethyl-2-perfluorobutylethyl (meth)acrylate, trifluoromethyl (meth)acrylate, perfluoroethyl (meth)acrylate, bis(trifluoromethyl)methyl (meth)acrylate, 2-trifluoromethyl-2-perfluoroethylethyl (meth)acrylate, 2-perfluorohexylethyl (meth)acrylate, 2-perfluorodecylethyl (meth)acrylate, 2-perfluorohexadecylethyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, chloroethyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, glycidyl (meth)acrylate, and 2-aminoethyl (meth)acrylate.

[0029] Furthermore, other monomers copolymerizable with the (meth)acrylic monomers may be used in combination. Examples of such other monomers include styrene-based monomers such as styrene, vinyltoluene, α-methylstyrene, chlorostyrene, and styrenesulfonic acid; fluorine-containing vinyl monomers such as perfluoroethylene, perfluoropropylene, and vinylidene fluoride; maleic acid and its derivatives such as maleic acid, maleic anhydride, maleic acid monoalkyl esters, and maleic acid dialkyl esters; fumaric acid and its derivatives such as fumaric acid, fumaric acid monoalkyl esters, and fumaric acid dialkyl esters; maleimide, methylmaleimide, ethylmaleimide, propylmaleimide, butylmaleimide, and hexamethylmaleimide. Examples of the other monomers include maleimide monomers such as xylmaleimide, octylmaleimide, dodecylmaleimide, stearylmaleimide, phenylmaleimide, and cyclohexylmaleimide; vinyl ester monomers such as vinyl acetate, vinyl propionate, vinyl pivalate, vinyl benzoate, and vinyl cinnamate; olefin monomers such as ethylene and propylene; conjugated diene monomers such as butadiene and isoprene; (meth)acrylamide; (meth)acrylonitrile; and vinyl monomers such as vinyl chloride, vinylidene chloride, allyl chloride, allyl alcohol, ethyl vinyl ether, and butyl vinyl ether. These other monomers may be used alone or in combination.

[0030] The main chain skeleton of the polyfunctional macromonomer (b2) is preferably composed of a soft polymer. Specifically, the monomer components forming the main chain skeleton of the polyfunctional macromonomer (b2) preferably contain 60% by weight or more of acrylate esters (excluding isobornyl acrylate, dicyclopentenyl acrylate, and dicyclopentanyl acrylate).

[0031] The (meth)acryloyl group contained in the polyfunctional macromonomer (b2) is preferably represented by the following general formula (7). CH2=C(R 8 )-COO-Z (7) (In the formula, R 8represents hydrogen or a methyl group. Z represents the main chain skeleton of the polyfunctional macromonomer (b2).

[0032] The polyfunctional macromonomer (b2) has, on average, more than one (meth)acryloyl group per molecule. The number of (meth)acryloyl groups per molecule of the polyfunctional macromonomer (b2) is, on average, preferably 1.1 to 5, more preferably 1.3 to 4, even more preferably 1.6 to 2.5, and particularly preferably 1.8 to 2.0. The polyfunctional macromonomer (b2) may have, as the (meth)acryloyl group, only acryloyl groups, only methacryloyl groups, or both acryloyl groups and methacryloyl groups.

[0033] The polyfunctional macromonomer (b2) may have a (meth)acryloyl group at either or both of the molecular chain terminal and the side chain of the (meth)acrylic acid ester polymer. From the viewpoint of excellent mechanical properties, it is preferable that the (meth)acryloyl group be present at the molecular chain terminal. It is particularly preferable that the polyfunctional macromonomer (b2) has a (meth)acryloyl group at each of the molecular chain terminals of the (meth)acrylic acid ester polymer.

[0034] The method for introducing a (meth)acryloyl group into the polyfunctional macromonomer (b2) is not particularly limited, and for example, the following methods can be used. The following methods may be used in combination. (iv) A method in which a monomer having a reactive functional group (V group) (e.g., acrylic acid, 2-hydroxyethyl acrylate) is copolymerized with a (meth)acrylic monomer, and then the resulting copolymer is reacted with a compound having a functional group reactive with the V group and a (meth)acryloyl group (e.g., 2-isocyanatoethyl (meth)acrylate). (v) A method in which (meth)acrylic monomers are polymerized by living radical polymerization, and then (meth)acryloyl groups are introduced into the molecular chain terminals (preferably both molecular chain terminals). Of these methods, method (v) is preferred because it allows for the introduction of (meth)acryloyl groups to the molecular chain terminals. Examples of "living radical polymerization" include those using cobalt porphyrin complexes as disclosed in the Journal of the American Chemical Society (J. Am. Chem. Soc.), Vol. 116, p. 7943, 1994; those using nitroxide radicals as disclosed in JP-A-2003-500378; and atom transfer radical polymerization (ATRP) using organic halides or sulfonyl halide compounds as initiators and transition metal complexes as catalysts as disclosed in JP-A-11-130931. Atom transfer radical polymerization is most preferred because it allows for the easy introduction of (meth)acryloyl groups to the molecular chain terminals.

[0035] It is also possible to use a method of obtaining a (meth)acrylic polymer using a metallocene catalyst and a thiol compound having at least one reactive silicon group in the molecule, as disclosed in JP-A-2001-040037.

[0036] The number-average molecular weight of the polyfunctional macromonomer (b2) is not particularly limited, but from the viewpoint of achieving both the adhesiveness exhibited by the curable composition and ease of handling of (b2), it is preferably 500 or more, more preferably 1,000 or more, and even more preferably 2,000 or more. It is also preferably 100,000 or less, more preferably 50,000 or less, even more preferably 40,000 or less, even more preferably 30,000 or less, particularly preferably 15,000 or less, and most preferably 10,000 or less. From the viewpoint of improving the strength of the cured product and the thixotropy of the curable composition, the number-average molecular weight of the polyfunctional macromonomer (b2) is preferably 8,000 or less, more preferably 6,000 or less, and even more preferably 5,000 or less.

[0037] The molecular weight distribution (weight average molecular weight (Mw) / number average molecular weight (Mn)) of the polyfunctional macromonomer (b2) is not particularly limited, but is preferably narrow. Specifically, it is preferably less than 2.0, more preferably 1.6 or less, even more preferably 1.5 or less, even more preferably 1.4 or less, and particularly preferably 1.3 or less.

[0038] The number average molecular weight (Mn) and weight average molecular weight (Mw) of the polyfunctional macromonomer (b2) are values ​​measured by GPC (polystyrene equivalent), and the detailed measurement method will be described in the Examples.

[0039] The (meth)acrylic acid ester copolymer (B) has a molecular chain composed of a polymer such as a (meth)acrylic acid ester (b1) and a molecular chain derived from the main chain skeleton of a polyfunctional macromonomer (b2). Since the polyfunctional macromonomer (b2) has more than one (meth)acryloyl group, which is a polymerizable group, per molecule, the (meth)acrylic acid ester copolymer (B) has a structure in which more than one molecular chain composed of a polymer such as a (meth)acrylic acid ester (b1) is bonded to one molecular chain of the polyfunctional macromonomer (b2). The molecular chain of the polyfunctional macromonomer (b2) may be introduced at the end of the molecular chain composed of a polymer such as a (meth)acrylic acid ester (b1), or may be introduced into a side chain of the molecular chain; however, the latter is preferred from the viewpoint of adhesiveness.

[0040] In particular, when the polyfunctional macromonomer (b2) has a (meth)acryloyl group at each end of the molecular chain of the (meth)acrylic acid ester polymer, an H-type structure can be formed in which a molecular chain composed of a polymer such as the (meth)acrylic acid ester (b1) is bonded to each end of the molecular chain of the polyfunctional macromonomer (b2). Here, the molecular chain of the polyfunctional macromonomer (b2) corresponds to the horizontal bar of the H, and the molecular chain composed of a polymer such as the (meth)acrylic acid ester (b1) corresponds to the two vertical bars contained in the H.

[0041] The content of the polyfunctional macromonomer (b2) is preferably 1 to 60 wt %, more preferably 5 to 50 wt %, and even more preferably 10 to 40 wt %, based on the total amount of the monomer components constituting the (meth)acrylic acid ester copolymer (B). In particular, when a cured product of the (meth)acrylic acid ester copolymer (B) with a high Young's modulus is desired, the content of the polyfunctional macromonomer (b2) is preferably less than 35 wt %. On the other hand, when a cured product of the (meth)acrylic acid ester copolymer (B) with a low Young's modulus is desired, the content of the polyfunctional macromonomer (b2) is preferably 35 wt % or more. Furthermore, the content of the polyfunctional macromonomer (b2) is preferably 0.2 mol % to 5.0 mol %, more preferably 0.6 mol % to 2.3 mol %, and even more preferably 0.8 mol % to 2.1 mol % of the monomer components constituting the (meth)acrylic acid ester copolymer (B). Within the above range, gelation during synthesis of the (meth)acrylic acid ester copolymer (B) can be suppressed, while the effects of the polyfunctional macromonomer (b2) can be achieved.

[0042] The number of polyfunctional macromonomers (b2) contained in one molecule of the (meth)acrylic acid ester copolymer (B) is, on average, preferably 0.01 or more, more preferably 0.03 or more, and even more preferably 0.05 or more, and is preferably 2.0 or less, more preferably 1.5 or less, and even more preferably 1.3 or less.

[0043] (Chain transfer agent (b3) having a mercapto group) By including a chain transfer agent (b3) having a mercapto group in the monomer components constituting the (meth)acrylic acid ester copolymer (B), it is possible to narrow the molecular weight distribution of the (meth)acrylic acid ester copolymer (B) and suppress gelation during synthesis of the (meth)acrylic acid ester copolymer (B), even though a polyfunctional macromonomer (b2) is used. It also becomes possible to preferentially synthesize polymer molecules in which one molecule of the polyfunctional macromonomer (b2) is introduced per molecule of the (meth)acrylic acid ester copolymer (B).

[0044] The chain transfer agent (b3) having a mercapto group may not have a reactive silicon group, but preferably further has a reactive silicon group. By having the chain transfer agent (b3) having a mercapto group have a reactive silicon group, it is possible to introduce a reactive silicon group into the end of a molecular chain composed of a polymer such as the (meth)acrylic acid ester (b1).

[0045] The chain transfer agent (b3) having a mercapto group is not particularly limited, and examples thereof include 3-mercaptopropyldimethoxymethylsilane, 3-mercaptopropyltrimethoxysilane, (mercaptomethyl)dimethoxymethylsilane, (mercaptomethyl)trimethoxysilane, n-dodecyl mercaptan, tert-dodecyl mercaptan, and lauryl mercaptan.

[0046] The content of the chain transfer agent (b3) having a mercapto group is preferably 0.1 to 10% by weight, more preferably 0.3 to 7% by weight, and even more preferably 0.5 to 5% by weight, based on the total amount of the monomer components constituting the (meth)acrylic acid ester copolymer (B). The content of the chain transfer agent (b3) having a mercapto group is preferably 0.1 to 15% by weight, more preferably 0.4 to 10% by weight, even more preferably 0.5 to 9% by weight, and particularly preferably 0.5 to 8% by weight, based on the total amount of the monomer components constituting the (meth)acrylic acid ester copolymer (B). Within these ranges, the effects of the chain transfer agent (b3) having a mercapto group can be achieved.

[0047] When a polyoxyalkylene polymer (A) and a (meth)acrylic acid copolymer (B) are used in combination, the content of the chain transfer agent (b3) having a mercapto group is preferably 1 to 30% by weight, more preferably 3 to 20% by weight, and even more preferably 5 to 15% by weight, based on the total amount of the monomer components constituting the (meth)acrylic acid ester copolymer (B). The content of the chain transfer agent (b3) having a mercapto group is preferably 0.4 to 18% by weight, more preferably 0.4 to 15% by weight, even more preferably 2 to 15% by weight, and particularly preferably 4 to 12% by weight, based on the total amount of the monomer components constituting the (meth)acrylic acid ester copolymer (B). Within these ranges, the effects of the chain transfer agent (b3) having a mercapto group can be achieved.

[0048] To improve the grafting rate of the polyfunctional macromonomer (b2), it is preferable to adjust the content of the polyfunctional macromonomer (b2) and the content of the chain transfer agent (b3) having a mercapto group so that the molar ratio of the (meth)acrylic acid ester polymer (b2) / the chain transfer agent (b3) having a mercapto group is 0.12 or more, more preferably 0.15 or more, and even more preferably 0.20 or more.

[0049] (Monomer (b4) having a reactive silicon group and a polymerizable unsaturated group) The monomer (b4) having a reactive silicon group and a polymerizable unsaturated group is an optional monomer and may not be used, but is preferably used. By using the monomer (b4), a reactive silicon group can be introduced into the side chain (non-terminal portion) of the molecular chain composed of a polymer such as the (meth)acrylic acid ester (b1).

[0050] Examples of the monomer (b4) having a reactive silicon group and a polymerizable unsaturated group include compounds having a (meth)acryloxy group and a reactive silicon group, such as 3-(meth)acryloxypropyltrimethoxysilane, 3-(meth)acryloxypropyltriethoxysilane, 3-(meth)acryloxypropyldimethoxymethylsilane, (meth)acryloxymethyltrimethoxysilane, and (meth)acryloxymethyldimethoxymethylsilane; and compounds having a vinyl group and a reactive silicon group, such as vinyltrimethoxysilane and vinyltriethoxysilane. These compounds may be used alone or in combination of two or more.

[0051] When the monomer (b4) is used, the content of the monomer (b4) is preferably 0.1 to 50% by weight, more preferably 0.3 to 30% by weight, and even more preferably 0.5 to 20% by weight, based on the total amount of the monomer components constituting the (meth)acrylic acid ester copolymer (B). From the viewpoints of improving the thixotropy of the curable composition and obtaining a cured product with high elongation, the content of the monomer (b4) is preferably 10% by weight or less, more preferably 5% by weight or less, and even more preferably 3% by weight or less.

[0052] The monomer components constituting the (meth)acrylic acid ester copolymer (B) may or may not contain other monomers that do not fall under any of the above-described (b1) to (b4). Examples of such other monomers include (meth)acrylic monomers that do not fall under the (meth)acrylic acid ester (b1) and monomers other than the (meth)acrylic monomers. Specifically, other monomers exemplified for the polyfunctional macromonomer (b2) can be used.

[0053] The polymerization methods (b1) to (b4) for forming the (meth)acrylic acid ester copolymer (B) are not particularly limited, but may be general free radical polymerization. According to this embodiment, despite being free radical polymerization, it is possible to control the polymerization, produce the (meth)acrylic acid ester copolymer (B) which is a block copolymer, and further have the advantage of being able to narrow the molecular weight distribution.

[0054] Examples of polymerization initiators that can be used in the free radical polymerization include azo compounds such as 2,2'-azobis(2-methylbutyronitrile), dimethyl 2,2'-azobis(2-methylpropionate), 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile), 2,2'-azobis[N-(2-propenyl)-2-methylpropionamide], and 1,1'-azobis(cyclohexane-1-carbonitrile). Diacyl peroxides such as benzoyl peroxide, isobutyryl peroxide, isononanoyl peroxide, decanoyl peroxide, lauroyl peroxide, parachlorobenzoyl peroxide, and di(3,5,5-trimethylhexanoyl) peroxide; diisopropyl percarbonate, di-sec-butyl percarbonate, di-2-ethylhexyl percarbonate, di-1-methylheptyl percarbonate, and di-3-methoxybutyl percarbonate peroxydicarbonates such as tert-butyl perbenzoate, tert-butyl peracetate, tert-butyl per-2-ethylhexanoate, tert-butyl perisobutyrate, tert-butyl perpivalate, tert-butyl diperadipate, and cumyl perneodecanoate; ketone peroxides such as methyl ethyl ketone peroxide and cyclohexanone peroxide; dialkyl peroxides such as di-tert-butyl peroxide, dicumyl peroxide, tert-butyl cumyl peroxide, and 1,1-di(tert-hexylperoxy)-3,3,5-trimethylcyclohexane; hydroperoxides such as cumene hydroxyperoxide and tert-butyl hydroperoxide; and peroxides such as 1,1-di(tert-hexylperoxy)-3,3,5-trimethylcyclohexane. These polymerization initiators may be used alone or in combination of two or more.

[0055] Examples of solvents that can be used in the free radical polymerization include aromatic solvents such as toluene, xylene, styrene, ethylbenzene, paradichlorobenzene, di-2-ethylhexyl phthalate, and di-n-butyl phthalate; aliphatic hydrocarbon solvents such as hexane, heptane, octane, cyclohexane, and methylcyclohexane; carboxylic acid ester compounds such as butyl acetate, n-propyl acetate, and isopropyl acetate; ketone compounds such as methyl isobutyl ketone and methyl ethyl ketone; dialkyl carbonate compounds such as dimethyl carbonate and diethyl carbonate; and alcohol compounds such as n-propanol, 2-propanol, n-butanol, 2-butanol, isobutanol, tert-butanol, and amyl alcohol. Among these, alcohol compounds are preferred because they narrow the molecular weight distribution. Aromatic solvents are preferred because of their high dissolving power. Aliphatic hydrocarbon solvents are preferred because of their low odor. The molecular weight distribution is affected by the amount of chain transfer agent (b3) added and the solvent. When the amount of chain transfer agent (b3) added is 3% by weight or less, the type of solvent has a large effect, and it is preferable to use isobutanol when it is desired to obtain a (meth)acrylic acid ester copolymer with a narrow molecular weight distribution.

[0056] The number average molecular weight of the (meth)acrylic acid ester copolymer (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. In particular, the number average molecular weight is preferably 7,000 or less, since this allows the (meth)acrylic acid ester copolymer (B) to have a low viscosity to be obtained. Furthermore, the number average molecular weight of the (meth)acrylic acid ester copolymer (B) is preferably 3,500 or less, since it exhibits low viscosity and good adhesiveness when mixed with the polyoxyalkylene polymer (A).

[0057] The weight-average molecular weight of the (meth)acrylic acid ester copolymer (B) is not particularly limited, but is preferably 500 to 80,000, more preferably 3,000 to 70,000, and particularly preferably 5,000 to 65,000, as calculated in terms of polystyrene by GPC measurement. In particular, a weight-average molecular weight of 30,000 or more is preferred, as this provides good mechanical properties. Furthermore, the weight-average molecular weight of the (meth)acrylic acid ester copolymer (B) is preferably 15,000 or less, as this provides a cured product with low viscosity and high strength when mixed with the polyoxyalkylene polymer (A).

[0058] The molecular weight distribution of the (meth)acrylic acid ester copolymer (B) is not particularly limited, but from the viewpoint of making the (meth)acrylic acid ester copolymer (B) low in viscosity, it is preferably from 3.0 to 11.0, more preferably from 3.2 to 10.0, and even more preferably from 3.4 to 8.0. The molecular weight distribution of the (meth)acrylic acid ester copolymer (B) can be determined from the number average molecular weight and weight average molecular weight obtained by GPC measurement.

[0059] The (meth)acrylic acid ester copolymer (B) can have reactive silicon groups by using a monomer (b4) having a reactive silicon group and a polymerizable unsaturated group, or by using a chain transfer agent (b3) having a reactive silicon group in addition to a mercapto group. Both methods may be used in combination. By using a monomer (b4) having a reactive silicon group and a polymerizable unsaturated group, reactive silicon groups can be randomly introduced into the side chains of molecular chains composed of polymers such as (meth)acrylic acid ester (b1). Furthermore, by using a chain transfer agent (b3) having a reactive silicon group in addition to a mercapto group, reactive silicon groups can be introduced into the terminals of molecular chains composed of polymers such as (meth)acrylic acid ester (b1).

[0060] However, in order to further introduce reactive silicon groups into the (meth)acrylic acid ester copolymer (B), the following method can also be used in combination. (vi) A method of copolymerizing a monomer having a reactive functional group (V group) with a (meth)acrylic acid ester (b1) or the like, and then reacting the resulting copolymer with a compound having a functional group reactive with the V group and a reactive silicon group. Specific examples include a method of copolymerizing 2-hydroxyethyl acrylate and then reacting with an isocyanate silane compound having a reactive silicon group, and a method of copolymerizing glycidyl acrylate and then reacting with an aminosilane compound having a reactive silicon group. (vii) A method of modifying the terminal functional groups of a (meth)acrylic acid ester copolymer synthesized by living radical polymerization to introduce reactive silicon groups. The (meth)acrylic acid ester copolymer obtained by living radical polymerization has terminal functional groups that can be easily introduced, and by modifying it, reactive silicon groups can be introduced at the terminals of the polymer.

[0061] Examples of the compound having a functional group reactive with the V group and a reactive silicon group used in the method (vi) include isocyanate silane compounds such as 3-isocyanatepropyldimethoxymethylsilane, 3-isocyanatepropyltrimethoxysilane, 3-isocyanatepropyltriethoxysilane, isocyanatemethyldimethoxymethylsilane, isocyanatemethyltrimethoxysilane, and isocyanatemethyltriethoxysilane; 3-glycidoxypropyldimethoxymethylsilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, and glycidoxymethylsilane; epoxy silane compounds such as 3-aminopropyldimethoxymethylsilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, aminomethyldimethoxymethylsilane, aminomethyltrimethoxysilane, aminomethyltriethoxysilane, N-cyclohexylaminomethyldimethoxymethylsilane, N-cyclohexylaminomethyltrimethoxysilane, N-cyclohexylaminomethyltriethoxysilane, and the like.

[0062] In the method (vii), any modification reaction can be used. Examples include a method using a compound having a reactive silicon group and a reactive group capable of reacting with a terminal functional group obtained by living radical polymerization, and a method in which a double bond is introduced into the polymer terminal using a compound having a reactive group and a double bond capable of reacting with a terminal functional group, and then a reactive silicon group is introduced using a hydrosilylation reaction or the like.

[0063] The reactive silicon group-containing (meth)acrylic acid ester copolymer (B) according to a preferred embodiment may contain a triblock copolymer, which may have the structure described below. That is, the reactive silicon group-containing (meth)acrylic acid ester copolymer (B) has a structure in which two first molecular chains are bonded via one second molecular chain, and both the first molecular chain and the second molecular chain are composed of molecular chains of the (meth)acrylic acid ester copolymer.

[0064] The first molecular chain is a molecular chain formed by copolymerization of (b1), (b2) (meth)acryloyl groups, (b3), and (b4). A reactive silicon group is bonded to this first molecular chain. When the chain transfer agent (b3) having a mercapto group has a reactive silicon group, the reactive silicon group is bonded to the terminal of the first molecular chain. When the monomer (b4) having a reactive silicon group and a polymerizable unsaturated group is used, the reactive silicon group is bonded to a non-terminal portion of the first molecular chain. On the other hand, the second molecular chain corresponds to the main chain skeleton of the (meth)acrylic acid ester polymer in the polyfunctional macromonomer (b2).

[0065] The two first molecular chains and one second molecular chain are linked in a manner different from that of a conventional ABA triblock copolymer, in that both ends of the second molecular chain are linked to the non-terminal portions of the first molecular chain, respectively, i.e., the triblock copolymer has an H-type structure, in which the two vertical bars in the H correspond to the two first molecular chains and the horizontal bar in the H corresponds to one second molecular chain.

[0066] However, the reactive silicon group-containing (meth)acrylic acid ester copolymer (B) is not limited to a triblock copolymer with an H-type structure, and may contain a block copolymer having another structure in addition to the triblock copolymer with an H-type structure. Examples of block copolymers having another structure include a block copolymer having a structure in which three first molecular chains are bonded via two second molecular chains.

[0067] The first molecular chain and the second molecular chain are bonded via an ester bond derived from the (meth)acryloyl group in the polyfunctional macromonomer (b2) (i.e., an ester bond corresponding to the ester bond in the formula (7)).

[0068] A polymer in which the first molecular chain is composed of a hard polymer and the second molecular chain is composed of a soft polymer is preferred because it can produce a cured product with high strength and high elongation. Here, a hard polymer refers to a polymer with a high glass transition temperature, and a soft polymer refers to a polymer with a low glass transition temperature. Specifically, the monomer components ((b1) and (b4)) constituting the first molecular chain preferably contain at least one monomer selected from the group consisting of methacrylic acid ester, isobornyl acrylate, dicyclopentenyl acrylate, and dicyclopentanyl acrylate. The proportion of the monomers in the monomer components constituting the first molecular chain is preferably 60% by weight or more, more preferably 70% by weight or more. Furthermore, the monomer component constituting the second molecular chain (the monomer component forming the main chain skeleton of the (meth)acrylic acid ester polymer in (b2)) preferably contains an acrylic acid ester (excluding isobornyl acrylate, dicyclopentenyl acrylate, and dicyclopentanyl acrylate). The proportion of the acrylic acid ester among the monomer components constituting the second molecular chain is preferably 60% by weight or more, more preferably 70% by weight or more.

[0069] Since the first molecular chain is formed by reacting with a chain transfer agent (b3) having a mercapto group, either end of the first molecular chain may have a structure represented by -SR as a substituent derived from (b3). In the formula, S represents a sulfur atom, and R represents a hydrocarbon group optionally having a reactive silicon group. Examples of the hydrocarbon group include an alkyl group, an aryl group, or an aralkyl group having 1 to 20 carbon atoms. The reactive silicon group is the reactive silicon group represented by the general formula (1) above. Specific examples of R include a reactive silicon group-containing methyl group, a reactive silicon group-containing propyl group, an n-dodecyl group, a tert-dodecyl group, and a lauryl group.

[0070] The reactive silicon group-containing (meth)acrylic acid ester copolymer (B) may contain a substituent derived from the mercapto group-containing chain transfer agent (b3), and therefore may contain sulfur atoms. The sulfur atom concentration in the (meth)acrylic acid ester copolymer (B) is preferably 700 ppm or more and 20,000 ppm or less, and more preferably 1,000 ppm or more and 15,000 ppm or less.

[0071] <<Curable composition>> One embodiment of the present invention relates to a curable composition containing the reactive silicon group-containing (meth)acrylic ester copolymer (B) described above. The curable composition may contain only the (meth)acrylic ester copolymer (B) as the reactive silicon group-containing polymer, or may contain a reactive silicon group-containing polyoxyalkylene polymer (A) in addition to the (meth)acrylic ester copolymer (B).

[0072] <<Polyoxyalkylene polymer (A) having reactive silicon groups>> <Reactive silicon group> The polyoxyalkylene polymer (A) has a reactive silicon group represented by the above-mentioned general formula (1). The reactive silicon group in the polyoxyalkylene polymer (A) may be the same as or different from the reactive silicon group in the (meth)acrylic acid ester copolymer (B).

[0073] R 5 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. 5 Specific examples of the group include a methyl group, an ethyl group, a chloromethyl group, a methoxymethyl group, and an N,N-diethylaminomethyl group. Of these, a methyl group, an ethyl group, a chloromethyl group, and a methoxymethyl group are preferred, and a methyl group and a methoxymethyl group are more preferred.

[0074] 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.

[0075] 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.

[0076] The polyoxyalkylene polymer (A) may have one or less reactive silicon groups on average at one terminal site, or may have more than one reactive silicon group on average at one terminal site.

[0077] Hereinafter, a polyoxyalkylene polymer (A) having, on average, more than one reactive silicon group per terminal will be described. "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. 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. The terminal moiety having two or more reactive silicon groups can be represented, for example, by the following general formula (2).

[0078] [ka]

[0079] (In the formula, R 1 ,R 3 are each independently a divalent linking group having 1 to 6 carbon atoms, and R 1 ,R 3 The atom bonded to each carbon atom adjacent to R is either carbon, oxygen, or nitrogen. 2 ,R 4 are each independently hydrogen or a hydrocarbon group having 1 to 10 carbon atoms. n is an integer of 1 to 10. R 5 , X, and c are as described above for formula (1).

[0080] R 1 , R3 R may be a divalent organic group having 1 to 6 carbon atoms, or may be a hydrocarbon group which may contain an oxygen atom. 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. 1 Specific examples of R include CH2OCH2, CH2O, and CH2, with CH2OCH2 being preferred. 3 Specific examples of the alkyl group include CH2 and CH2CH2, with CH2 being preferred.

[0081] R 2 , R 4 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. 2 , R 4 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.

[0082] In a particularly preferred embodiment, the terminal moiety represented by general formula (2) is R 1 is CH2OCH2 and R 3 is CH2 and R 2 and R 4 are each a hydrogen atom. n is preferably an integer of 1 to 5, more preferably an integer of 1 to 3, and even more preferably 1 or 2. However, n is not limited to a single value, and may be a mixture of multiple values.

[0083] The polyoxyalkylene polymer (A) may have an average of 1.0 or less reactive silicon groups per terminal, but preferably has an average of more than 1.0 reactive silicon groups per terminal. The average number is more preferably 1.1 or more, even more preferably 1.5 or more, and even more preferably 2.0 or more. The average number is preferably 5 or less, more preferably 3 or less.

[0084] 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.

[0085] 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.

[0086] 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, from the viewpoint of the strength of the cured product, and is preferably 6.0 or less, more preferably 5.5 or less, and most preferably 5.0 or less, from the viewpoint of the elongation of the cured product.

[0087] <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.

[0088] 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.

[0089] 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.

[0090] 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, and particularly preferably 1.4 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.

[0091] The main chain structure of the polyoxyalkylene polymer (A) may be linear or branched.

[0092] <Method for synthesizing polyoxyalkylene polymer (A)> Next, a method for synthesizing the polyoxyalkylene polymer (A) will be described. A polyoxyalkylene polymer (A) having an average of one or less reactive silicon group per terminal can be obtained by introducing one carbon-carbon unsaturated bond per terminal of a hydroxyl-terminated polymer obtained by polymerization, followed by reaction with a reactive silicon group-containing compound that reacts with the carbon-carbon unsaturated bond. To introduce the carbon-carbon unsaturated bond into the polymer, a halogenated hydrocarbon compound having a carbon-carbon unsaturated bond, as described below, can be used. Examples of such halogenated hydrocarbon compounds include halogenated hydrocarbon compounds having a carbon-carbon double bond, such as allyl chloride, as described below, and halogenated hydrocarbon compounds having a carbon-carbon triple bond, such as propargyl chloride.

[0093] The polyoxyalkylene polymer (A) having more than one reactive silicon group on average at each terminal site is preferably obtained by introducing two or more carbon-carbon unsaturated bonds into each 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.

[0094] (polymerization) The polyoxyalkylene polymer (A) is preferably produced by polymerizing an epoxy compound with an initiator having a hydroxyl group using a composite metal cyanide complex catalyst such as zinc hexacyanocobaltate glyme complex.

[0095] 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 polyoxypropylene glycol, polyoxypropylene triol, allyl alcohol, polypropylene monoallyl ether, and polypropylene monoalkyl ether.

[0096] 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.

[0097] (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.

[0098] As the alkali metal salt, sodium hydroxide, sodium methoxide, sodium ethoxide, potassium hydroxide, potassium methoxide, and potassium ethoxide are preferred, and sodium methoxide and potassium methoxide are more preferred, with sodium methoxide being particularly preferred in terms of availability.

[0099] 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.

[0100] As the epoxy compound having a carbon-carbon unsaturated bond, in particular, a compound of the general formula (3):

[0101] [ka]

[0102] (R in the formula 1 , R 2is the same as 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.

[0103] The amount of the epoxy compound having a carbon-carbon unsaturated bond added 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.

[0104] 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.

[0105] Examples of halogenated hydrocarbon compounds having a carbon-carbon unsaturated bond 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 and methallyl chloride because of their ease of handling.

[0106] 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.

[0107] 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.

[0108] (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. (iii) A method of reacting a reactive group-containing polymer with a silane coupling agent. Examples of combinations of reactive groups of the reactive group-containing polymer and the silane coupling agent include, but are not limited to, a hydroxyl group and an isocyanate group, a hydroxyl group and an epoxy group, an amino group and an isocyanate group, an amino group and a thioisocyanate group, an amino group and an epoxy group, an amino group and an α,β-unsaturated carbonyl group (a reaction by Michael addition), a carboxyl group and an epoxy group, and an unsaturated bond and a mercapto group.

[0109] 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. Methods (ii) and (iii) are preferred because they offer a wide range of reaction options and make it easy to increase the rate of reactive silicon groups introduced.

[0110] The hydrosilane compound that can be used in method (i) is not particularly limited, but examples thereof include trimethoxysilane, triethoxysilane, tris(2-propenyloxy)silane, triacetoxysilane, dimethoxymethylsilane, diethoxymethylsilane, dimethoxyethylsilane, (chloromethyl)dimethoxysilane, (chloromethyl)diethoxysilane, (methoxymethyl)dimethoxysilane, (methoxymethyl)diethoxysilane, (N,N-diethylaminomethyl)dimethoxysilane, and (N,N-diethylaminomethyl)diethoxysilane.

[0111] The amount of the hydrosilane compound used, 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 the viewpoint of reactivity to 10, and more preferably from the viewpoint of economy to 2.3.

[0112] 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.

[0113] Examples of silane coupling agents that can be used in the above method (ii) or (iii) include mercaptosilanes that react with unsaturated bonds, such as 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyldimethoxymethylsilane, 3-mercaptopropyltriethoxysilane, mercaptomethyltriethoxysilane, and mercaptomethyldimethoxymethylsilane; and 3-isocyanatepropyltrimethoxysilane, 3-isocyanatepropyldimethoxymethylsilane, 3-isocyanatepropyltriethoxysilane, and isocyanate methyltriethoxysilane that react with hydroxyl groups. isocyanate silanes such as isocyanatemethyltrimethoxysilane, isocyanatemethyltriethoxysilane, isocyanatemethyldimethoxymethylsilane; epoxy silanes such as 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyldimethoxymethylsilane, 3-glycidoxypropyltriethoxysilane, glycidoxymethyltrimethoxysilane, glycidoxymethyltriethoxysilane, glycidoxymethyldimethoxymethylsilane, which react with hydroxyl groups, amino groups, or carboxyl groups; Reacting with alkyl groups, 3-aminopropyltrimethoxysilane, 3-aminopropyldimethoxymethylsilane, 3-aminopropyltriethoxysilane, 3-(2-aminoethyl)propyltrimethoxysilane, 3-(2-aminoethyl)propyldimethoxymethylsilane, 3-(2-aminoethyl)propyltriethoxysilane, 3-(N-ethylamino)-2-methylpropyltrimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-benzoyl aminosilanes such as N-3-aminopropyltrimethoxysilane, N-cyclohexylaminomethyltriethoxysilane, N-cyclohexylaminomethyldiethoxymethylsilane, N-phenylaminomethyltrimethoxysilane, (2-aminoethyl)aminomethyltrimethoxysilane, N,N'-bis[3-(trimethoxysilyl)propyl]ethylenediamine, and bis(3-(trimethoxysilyl)propyl)amine; and hydroxyalkylsilanes such as 3-hydroxypropyltrimethoxysilane and hydroxymethyltriethoxysilane.

[0114] The main chain of the polymer (A) may have an ester bond or a bond represented by the general formula (4): -NR 6 -C(=O)- (4) (In the formula, R 6 represents an organic group having 1 to 10 carbon atoms or a hydrogen atom).

[0115] Cured products obtained from curable compositions containing polymer (A) containing ester bonds or amide segments may have high hardness and strength due to the action of hydrogen bonds, etc. However, polymer (A) containing amide segments, etc. may be cleaved by heat, etc. In addition, curable compositions containing polymer (A) containing amide segments, etc. tend to have high viscosity. Taking into account the above advantages and disadvantages, polyoxyalkylenes containing amide segments, etc., or polyoxyalkylenes not containing amide segments, etc. may be used as polymer (A).

[0116] Examples of the amide segment represented by the general formula (4) include those formed by a reaction between an isocyanate group and a hydroxyl group, a reaction between an amino group and a carbonate, a reaction between an isocyanate group and an amino group, a reaction between an isocyanate group and a mercapto group, etc. In addition, those formed by a reaction between the amide segment containing an active hydrogen atom and an isocyanate group are also included in the amide segment represented by the general formula (4).

[0117] The polymer (A) containing an amide segment can be produced, for example, by reacting a polyoxyalkylene having an active hydrogen-containing group at its terminal with an excess of a polyisocyanate compound to synthesize a polymer having an isocyanate group at its terminal, and then, or simultaneously with the synthesis of the polymer, reacting a compound of the general formula (5): ZR 7 -SiR 5 c X 3-c (5) (In the formula, R5 , X and c are the same as above. 7 is a divalent organic group, preferably a divalent hydrocarbon group having 1 to 20 carbon atoms. Z is a hydroxyl group, a carboxyl group, a mercapto group, a primary amino group, or a secondary amino group. The Z group of the silicon compound represented by the following formula (I) is reacted with all or part of the isocyanate groups of the synthesized polymer.

[0118] The silicon compound represented by the general formula (5) is not particularly limited, and examples thereof include amino group-containing silanes such as γ-aminopropyldimethoxymethylsilane, γ-aminopropyltrimethoxysilane, N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, N-(β-aminoethyl)-γ-aminopropyldimethoxymethylsilane, (N-phenyl)-γ-aminopropyltrimethoxysilane, and N-ethylaminoisobutyltrimethoxysilane; hydroxyl group-containing silanes such as γ-hydroxypropyltrimethoxysilane; and mercapto group-containing silanes such as γ-mercaptopropyltrimethoxysilane and mercaptomethyltriethoxysilane. Furthermore, as described in JP-A-6-211879 (U.S. Patent No. 5,364,955), JP-A-10-53637 (U.S. Patent No. 5,756,751), JP-A-10-204144 (EP 0831108), JP-A-2000-169544, and JP-A-2000-169545, Michael addition reaction products of various α,β-unsaturated carbonyl compounds and primary amino group-containing silanes, or Michael addition reaction products of various (meth)acryloyl group-containing silanes and primary amino group-containing compounds can also be used as the silicon compound represented by the general formula (5).

[0119] The polymer (A) containing an amide segment can be produced, for example, by reacting a polyoxyalkylene having an active hydrogen-containing group at its terminal with a compound represented by the general formula (6): O=C=NR 7 -SiR 5 c X 3-c (6) (In the formula, R 7 , R5 , X and c are the same as above. A method of reacting a reactive silicon group-containing isocyanate compound represented by the following formula (I) can be mentioned.

[0120] The reactive silicon group-containing isocyanate compound represented by the general formula (6) is not particularly limited, and examples thereof include γ-trimethoxysilylpropyl isocyanate, γ-triethoxysilylpropyl isocyanate, γ-methyldimethoxysilylpropyl isocyanate, γ-methyldiethoxysilylpropyl isocyanate, γ-(methoxymethyl)dimethoxysilylpropyl isocyanate, trimethoxysilylmethyl isocyanate, triethoxymethylsilylmethyl isocyanate, dimethoxymethylsilylmethyl isocyanate, diethoxymethylsilylmethyl isocyanate, and (methoxymethyl)dimethoxysilylmethyl isocyanate.

[0121] When the polymer (A) contains an amide segment, the number (average number) of amide segments per molecule of the polymer (A) is preferably 1 to 10, more preferably 1.5 to 5, and particularly preferably 2 to 3. If this number is less than 1, the curability may be insufficient, and conversely, if it is more than 10, the polymer (A) may become highly viscous and difficult to handle. In order to reduce the viscosity of the curable composition and improve workability, it is preferable that the polymer (A) does not contain an amide segment.

[0122] Methods of blending a polyoxyalkylene polymer (A) with a (meth)acrylic acid ester copolymer (B) have been proposed in JP-A Nos. 59-122541, 63-112642, 6-172631, and 11-116763, etc. Another method that can be used is to synthesize the (meth)acrylic acid ester copolymer (B) by copolymerizing the monomer components that constitute the (meth)acrylic acid ester copolymer (B) in the presence of a polyoxypropylene polymer (A) having a reactive silicon group.

[0123] The weight ratio of polyoxyalkylene polymer (A) to (meth)acrylic acid ester copolymer (B) is preferably 95:5 to 50:50. Within this range, a cured product with high tensile strength and adhesive strength can be obtained. The weight ratio of (A):(B) is more preferably 80:20 to 50:50, and even more preferably 70:30 to 50:50.

[0124] <<Silanol condensation catalyst (C)>> The curable composition according to one embodiment of the present invention preferably contains a silanol condensation catalyst (C) 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.

[0125] Examples of the silanol condensation catalyst (C) include organotin compounds, metal carboxylic acid salts, amine compounds, carboxylic acids, and alkoxy metals.

[0126] 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.

[0127] 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.

[0128] 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.

[0129] 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.

[0130] 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).

[0131] When the silanol condensation catalyst (C) is used, the amount used 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 (meth)acrylic acid ester polymer (B) or per 100 parts by weight of the polyoxyalkylene polymer (A) and the (meth)acrylic acid ester polymer (B) combined.

[0132] <<Other additives>> In addition to the polyoxyalkylene polymer (A), the optional (meth)acrylic acid ester polymer (B), and the optional silanol condensation catalyst (C), the curable composition according to one embodiment of the present invention may contain additives such as fillers, adhesion promoters, anti-sagging agents, antioxidants, light stabilizers, UV absorbers, and other resins. Furthermore, the curable composition according to one embodiment of the present invention may contain various additives as needed to adjust the physical properties of the composition or its cured product. Examples of such additives include plasticizers, 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.

[0133] <Filler> The curable composition according to one embodiment of the present invention may contain a filler, such as ground calcium carbonate, colloidal calcium carbonate, magnesium carbonate, diatomaceous earth, clay, talc, titanium oxide, fumed silica, precipitated silica, crystalline silica, fused silica, wet silica, silicic acid anhydride, silicic acid hydrate, alumina, carbon black, ferric oxide, fine aluminum powder, zinc oxide, activated zinc oxide, PVC powder, PMMA powder, glass fiber, and filament.

[0134] The amount of filler used is preferably 1 to 300 parts by weight, more preferably 10 to 250 parts by weight, per 100 parts by weight of the (meth)acrylic acid ester polymer (B) or per 100 parts by weight of the total of the polyoxyalkylene polymer (A) and the (meth)acrylic acid ester polymer (B).

[0135] For the purpose of reducing the weight (specific gravity) of the composition, organic balloons or inorganic balloons may be added.

[0136] <Adhesion promoter> The curable composition according to one embodiment of the present invention may contain an adhesion promoter. As the adhesion promoter, a silane coupling agent or a reaction product of a silane coupling agent may be used.

[0137] Specific examples of the silane coupling agent include amino group-containing silanes such as γ-aminopropyltrimethoxysilane, γ-aminopropylmethyldimethoxysilane, N-β-aminoethyl-γ-aminopropyltrimethoxysilane, N-β-aminoethyl-γ-aminopropylmethyldimethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, and (2-aminoethyl)aminomethyltrimethoxysilane; γ-isocyanatepropyltrimethoxysilane, γ-isocyanatepropyltriethoxysilane, and γ-isopropyltriethoxysilane. Examples of suitable adhesion promoters include isocyanate group-containing silanes such as cyanatepropylmethyldimethoxysilane, 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. The adhesion promoters may be used alone or in combination of two or more. Reaction products of various silane coupling agents may also be used.

[0138] The amount of the silane coupling agent used is preferably 0.1 to 20 parts by weight, more preferably 0.5 to 10 parts by weight, per 100 parts by weight of the (meth)acrylic acid ester polymer (B) or per 100 parts by weight of the total of the polyoxyalkylene polymer (A) and the (meth)acrylic acid ester polymer (B).

[0139] <Anti-sagging agent> The curable composition according to one embodiment of the present invention may contain an anti-sagging agent as needed to prevent sagging and improve workability. Examples of the anti-sagging agent include, but are not limited to, polyamide waxes; hydrogenated castor oil derivatives; and metal soaps such as calcium stearate, aluminum stearate, and barium stearate. These anti-sagging agents may be used alone or in combination of two or more.

[0140] The amount of the anti-sagging agent used is preferably 0.1 to 20 parts by weight per 100 parts by weight of the (meth)acrylic acid ester polymer (B) or per 100 parts by weight of the total of the polyoxyalkylene polymer (A) and the (meth)acrylic acid ester polymer (B).

[0141] <Antioxidants> The curable composition according to one embodiment of the present invention may contain an antioxidant (antiaging agent). The use of an antioxidant can improve the weather resistance of the cured product. Examples of antioxidants include hindered phenols, monophenols, bisphenols, and polyphenols. Specific examples of antioxidants are also described in JP-A-4-283259 and JP-A-9-194731.

[0142] The amount of antioxidant used is preferably 0.1 to 10 parts by weight, more preferably 0.2 to 5 parts by weight, per 100 parts by weight of the (meth)acrylic acid ester polymer (B) or per 100 parts by weight of the total of the polyoxyalkylene polymer (A) and the (meth)acrylic acid ester polymer (B).

[0143] <Light stabilizer> The curable composition according to one embodiment of the present invention 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.

[0144] The amount of the light stabilizer used is preferably 0.1 to 10 parts by weight, more preferably 0.2 to 5 parts by weight, per 100 parts by weight of the (meth)acrylic acid ester polymer (B) or per 100 parts by weight of the total of the polyoxyalkylene polymer (A) and the (meth)acrylic acid ester polymer (B).

[0145] <UV absorber> The curable composition according to one embodiment of the present invention 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. Specific examples 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).

[0146] The amount of the ultraviolet absorber used is preferably 0.1 to 10 parts by weight, more preferably 0.2 to 5 parts by weight, per 100 parts by weight of the (meth)acrylic acid ester polymer (B) or per 100 parts by weight of the total of the polyoxyalkylene polymer (A) and the (meth)acrylic acid ester polymer (B).

[0147] The curable composition according to one embodiment of the present invention is preferably prepared as a one-component composition in which all ingredients are mixed in advance, sealed, and stored, and then cured by moisture in the air after application.

[0148] When the curable composition is a one-component type, all of the components are blended in advance, and therefore, it is preferable to dehydrate and dry the components containing water before use, or to dehydrate them by reducing the pressure during blending and kneading.

[0149] Suitable dehydration methods for solid materials such as powders include heat drying, while for liquid materials, vacuum dehydration or dehydration methods using synthetic zeolite, activated alumina, silica gel, quicklime, magnesium oxide, etc. Alternatively, a small amount of an isocyanate compound may be added to the material to allow the isocyanate group to react with water for dehydration. Alternatively, an oxazolidine compound such as 3-ethyl-2-methyl-2-(3-methylbutyl)-1,3-oxazolidine may be added to the material to allow the reaction with water for dehydration.

[0150] In addition to these dehydration drying methods, the storage stability can be further improved by adding a lower alcohol such as methanol or ethanol, or an alkoxysilane compound, such as n-propyltrimethoxysilane, vinyltrimethoxysilane, vinylmethyldimethoxysilane, γ-mercaptopropylmethyldimethoxysilane, γ-mercaptopropylmethyldiethoxysilane, or γ-glycidoxypropyltrimethoxysilane.

[0151] The amount of the dehydrating agent, particularly the alkoxysilane compound, used is preferably 0.1 to 20 parts by weight, more preferably 0.5 to 10 parts by weight, per 100 parts by weight of the (meth)acrylic acid ester polymer (B) or per 100 parts by weight of the total of the polyoxyalkylene polymer (A) and the (meth)acrylic acid ester polymer (B).

[0152] The method for preparing the curable composition according to one embodiment of the present invention is not particularly limited, and may be a conventional method, such as blending the above components and kneading them at room temperature or under heat using a mixer, roll, kneader, or the like, or dissolving the above components in a small amount of an appropriate solvent and mixing them.

[0153] The curable composition according to one embodiment of the present invention can be used as a sealing material, adhesive, mold release agent, vibration-proofing material, vibration-damping material, soundproofing material, foam material, paint, spray material, waterproof coating agent, etc. for buildings, ships, automobiles, roads, etc.

[0154] The cured product obtained by curing the curable composition according to one embodiment of the present invention has good adhesion to various adherends, and therefore the curable composition is more preferably used as a sealant or an adhesive.

[0155] The curable composition according to one embodiment of the present invention can be used in a variety of applications, including electrical and electronic component materials such as a sealing material for the back surface of a solar cell, electrical insulating materials such as insulating coating materials for electric wires and cables, elastic adhesives, contact adhesives, spray-type sealants, crack repair materials, tiling adhesives, powder paints, casting materials, medical rubber materials, medical pressure-sensitive adhesives, medical device sealants, food packaging materials, joint sealants for exterior materials such as sizing boards, coating materials, primers, conductive materials for electromagnetic wave shielding, thermally conductive materials, hot melt materials, potting agents for electrical and electronic applications, films, gaskets, various molding materials, anti-rust and waterproof sealants for the edge (cut portion) of wired glass and laminated glass, and liquid sealants used in automotive parts, electrical parts, and various machine parts.

[0156] A cured product of the curable composition according to one embodiment of the present invention can adhere to a wide range of substrates, such as glass, porcelain, wood, metal, and resin molded products, either alone or in combination with a primer, and therefore the curable composition can also be used as a sealing composition or an adhesive composition.

[0157] The curable composition according to one embodiment of the present invention can also be used as an adhesive for interior panels, an adhesive for exterior panels, a tiling adhesive, an adhesive for stone cladding, an adhesive for ceiling finishing, an adhesive for floor finishing, an adhesive for wall finishing, an adhesive for vehicle panels, an adhesive for assembling electrical, electronic and precision equipment, a sealant for direct glazing, a sealant for double glazing, a sealant for the SSG construction method, or a sealant for working joints in buildings. [Example]

[0158] The present invention will be specifically explained below by way of examples, but the present invention is not limited to these examples.

[0159] (Number average molecular weight and weight average molecular weight) The number average molecular weight and weight average molecular weight in the examples are GPC molecular weights measured under the following conditions. Liquid delivery system: Tosoh HLC-8220GPC Column: Tosoh TSK-GEL H type Solvent: THF Molecular weight: Polystyrene equivalent Measurement temperature: 40℃

[0160] (Sulfur atom concentration) The sulfur atom concentration is a theoretical value calculated from the total amount of the monomer components used in the production of the (meth)acrylic acid ester copolymer (B) and the amount of the chain transfer agent (b3) having a mercapto group.

[0161] (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 with hydroxyl groups at both ends, a number-average molecular weight of 28,500 (17,700 molecular weight calculated as the end group), and a molecular weight distribution (Mw / Mn) of 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.

[0162] To 100 parts by weight of the resulting polyoxypropylene having an average of 2.0 carbon-carbon unsaturated bonds at one terminal, 36 ppm of platinum divinyldisiloxane complex (3 wt% isopropanol solution in terms of platinum) was added, and 2.2 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 linear reactive silicon-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.

[0163] (Synthesis Example 2) 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 with hydroxyl groups at both ends, a number-average molecular weight of 28,500 (17,700 molecular weight calculated as end groups), and a molecular weight distribution (Mw / Mn) of 1.21. To the hydroxyl-terminated polyoxypropylene, 1.2 molar equivalents of sodium methoxide were added as a 28% methanol solution. After removing the methanol by vacuum devolatilization, 1.5 molar equivalents of 3-chloro-1-propene were added to the hydroxyl-terminated polyoxypropylene, and the reaction was carried out at 130°C for 2 hours. 100 parts by weight of the obtained unpurified allyl group-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 then centrifuged to remove the water. After that, 300 parts by weight of water was further mixed and stirred with the obtained hexane solution, and the water was again removed by centrifugation, and the hexane was then removed by devolatilization under reduced pressure. To 100 parts by weight of the resulting polyoxypropylene, 36 ppm of platinum divinyldisiloxane complex (a 3 wt% isopropanol solution calculated as platinum) was added, and 1.0 part by weight of dimethoxymethylsilane was slowly added dropwise while stirring. The resulting mixture was reacted at 90°C for 2 hours, and then the unreacted dimethoxymethylsilane was distilled off under reduced pressure to obtain a linear reactive silicon group-containing polyoxypropylene polymer (A-2) having an average of 1.6 silicon groups per molecule and a number-average molecular weight of 28,500.

[0164] (Synthesis Example 3) A deoxygenated reactor was charged with 0.42 parts by weight of cuprous bromide and 20.0 parts by weight of butyl acrylate, and the mixture was heated and stirred. 8.8 parts by weight of acetonitrile as the polymerization solvent and 9.4 parts by weight of diethyl 2,5-dibromoadipate as the initiator were added and mixed. The temperature of the mixture was adjusted to approximately 80°C, and pentamethyldiethylenetriamine (hereinafter referred to as triamine) was added to initiate the polymerization reaction. Next, 80.0 parts by weight of butyl acrylate was gradually added to advance the polymerization reaction. During the polymerization, additional triamine was added as needed to adjust the polymerization rate. The total amount of triamine used during the polymerization was 0.15 parts by weight. When the monomer conversion rate (polymerization reaction rate) reached approximately 95% or higher, volatile components were removed by devolatilization under reduced pressure to obtain a polymer concentrate.

[0165] The concentrate was diluted with toluene, and a filter aid, an adsorbent (Kyoward 700SEN, manufactured by Kyowa Chemical Industry Co., Ltd.), and hydrotalcite (Kyoward 500SH, manufactured by Kyowa Chemical Industry Co., Ltd.) were added. The mixture was heated and stirred at about 80 to 100°C, and the solid components were removed by filtration. The filtrate was concentrated under reduced pressure to obtain a crude polymer.

[0166] The crude polymer, 11.2 parts by weight of potassium acrylate, 100 ppm of 4-hydroxy-TEMPO, and 100 parts by weight of dimethylacetamide as a solvent were added and reacted at 70°C for 3 hours. The solvent was then removed by distillation under reduced pressure to obtain a polymer concentrate. The concentrate was diluted with toluene, and the solid components were removed by filtration. The filtrate was concentrated under reduced pressure to obtain a multifunctional macromonomer (b2-1) with acryloyl groups at both ends (i.e., two acryloyl groups per polymer molecule), a number average molecular weight of 4,030 (GPC molecular weight), and a molecular weight distribution (Mw / Mn) of 1.23.

[0167] (Synthesis Example 4) A deoxygenated reactor was charged with 0.42 parts by weight of cuprous bromide and 20.0 parts by weight of butyl acrylate, and the mixture was heated and stirred. 8.8 parts by weight of acetonitrile as the polymerization solvent and 4.7 parts by weight of diethyl 2,5-dibromoadipate as the initiator were added and mixed. The temperature of the mixture was adjusted to approximately 80°C, and pentamethyldiethylenetriamine (hereinafter referred to as triamine) was added to initiate the polymerization reaction. Next, 80.0 parts by weight of butyl acrylate was gradually added to advance the polymerization reaction. During the polymerization, additional triamine was added as needed to adjust the polymerization rate. The total amount of triamine used during the polymerization was 0.15 parts by weight. When the monomer conversion rate (polymerization reaction rate) reached approximately 95% or higher, volatile matter was removed by devolatilization under reduced pressure to obtain a polymer concentrate.

[0168] The concentrate was diluted with toluene, and a filter aid, an adsorbent (Kyoward 700SEN, manufactured by Kyowa Chemical Industry Co., Ltd.), and hydrotalcite (Kyoward 500SH, manufactured by Kyowa Chemical Industry Co., Ltd.) were added. The mixture was heated and stirred at about 80 to 100°C, and the solid components were removed by filtration. The filtrate was concentrated under reduced pressure to obtain a crude polymer.

[0169] The crude polymer, 5.4 parts by weight of potassium acrylate, 100 ppm of 4-hydroxy-TEMPO, and 100 parts by weight of dimethylacetamide as a solvent were added and reacted at 70°C for 3 hours. The solvent was then removed by distillation under reduced pressure to obtain a polymer concentrate. The concentrate was diluted with toluene, and the solid components were removed by filtration. The filtrate was concentrated under reduced pressure to obtain a multifunctional macromonomer (b2-2) with acryloyl groups at both ends (i.e., two acryloyl groups per polymer molecule), a number average molecular weight of 8,590 (GPC molecular weight), and a molecular weight distribution (Mw / Mn) of 1.15.

[0170] (Synthesis Example 5) A deoxygenated reactor was charged with 0.42 parts by weight of cuprous bromide and 20.0 parts by weight of butyl acrylate, and the mixture was heated and stirred. 8.8 parts by weight of acetonitrile as the polymerization solvent and 3.1 parts by weight of diethyl 2,5-dibromoadipate as the initiator were added and mixed. The temperature of the mixture was adjusted to approximately 80°C, and pentamethyldiethylenetriamine (hereinafter referred to as triamine) was added to initiate the polymerization reaction. Next, 80.0 parts by weight of butyl acrylate was gradually added to advance the polymerization reaction. During the polymerization, additional triamine was added as needed to adjust the polymerization rate. The total amount of triamine used during the polymerization was 0.15 parts by weight. When the monomer conversion rate (polymerization reaction rate) reached approximately 95% or higher, volatile components were removed by devolatilization under reduced pressure to obtain a polymer concentrate. The concentrate was diluted with toluene, and a filter aid, an adsorbent (Kyoward 700SEN, manufactured by Kyowa Chemical Industry Co., Ltd.), and hydrotalcite (Kyoward 500SH, manufactured by Kyowa Chemical Industry Co., Ltd.) were added. The mixture was heated and stirred at about 80 to 100°C, and the solid components were removed by filtration. The filtrate was concentrated under reduced pressure to obtain a crude polymer. The crude polymer, 3.8 parts by weight of potassium acrylate, 100 ppm of 4-hydroxy-TEMPO, and 100 parts by weight of dimethylacetamide as a solvent were added and reacted at 70°C for 3 hours. The solvent was then removed by distillation under reduced pressure to obtain a polymer concentrate. The concentrate was diluted with toluene, and the solid components were removed by filtration. The filtrate was concentrated under reduced pressure to obtain a multifunctional macromonomer (b2-3) with acryloyl groups at both ends (i.e., two acryloyl groups per polymer molecule), a number-average molecular weight of 11,410 (GPC molecular weight), and a molecular weight distribution (Mw / Mn) of 1.27.

[0171] (Synthesis Example 6) A four-necked flask equipped with a stirrer was charged with 48.0 parts by weight of isobutanol and heated to 105°C under a nitrogen atmosphere. A mixed solution of 59.0 parts by weight of butyl acrylate, 10.0 parts by weight of stearyl methacrylate, 30.0 parts by weight of the multifunctional macromonomer (b2-1) prepared in Synthesis Example 3, 1.0 parts by weight of 3-methacryloxypropyltrimethoxysilane, 7.2 parts by weight of 3-mercaptopropyltrimethoxysilane, and 2.5 parts by weight of 2,2'-azobis(2-methylbutyronitrile) dissolved in 22.7 parts by weight of isobutanol was added dropwise over 5 hours. Polymerization was further carried out at 105°C for 2 hours, yielding an isobutanol solution (solids content 60%) of a reactive silicon group-containing (meth)acrylic acid ester copolymer (B-1) having a number average molecular weight of 2,280 (GPC molecular weight). The solid content of the solution had a polyfunctional macromonomer equivalent of 0.069 mmol / g, a reactive silicon group equivalent of 0.38 mmol / g, and a sulfur atom content of 10941 ppm.

[0172] (Synthesis Example 7) A four-necked flask equipped with a stirrer was charged with 48.0 parts by weight of isobutanol and heated to 105°C under a nitrogen atmosphere. A mixed solution of 59.0 parts by weight of butyl acrylate, 10.0 parts by weight of stearyl methacrylate, 85.0 parts by weight of the multifunctional macromonomer (b2-1) prepared in Synthesis Example 3, 1.0 parts by weight of 3-methacryloxypropyltrimethoxysilane, 7.2 parts by weight of 3-mercaptopropyltrimethoxysilane, and 2.5 parts by weight of 2,2'-azobis(2-methylbutyronitrile) dissolved in 22.7 parts by weight of isobutanol was added dropwise over 5 hours. Polymerization was further carried out at 105°C for 2 hours, yielding an isobutanol solution (solids content 60%) of a reactive silicon group-containing (meth)acrylic acid ester copolymer (B-2) having a number average molecular weight of 3,720 (GPC molecular weight). The solid content of the solution had a polyfunctional macromonomer equivalent of 0.13 mmol / g, a reactive silicon group equivalent of 0.25 mmol / g, and a sulfur atom content of 7185 ppm.

[0173] (Synthesis Example 8) A four-necked flask equipped with a stirrer was charged with 48.0 parts by weight of isobutanol and heated to 105°C under a nitrogen atmosphere. A mixed solution of 59.0 parts by weight of butyl acrylate, 10.0 parts by weight of stearyl methacrylate, 85.0 parts by weight of the multifunctional macromonomer (b2-1) prepared in Synthesis Example 3, 1.0 parts by weight of 3-methacryloxypropyltrimethoxysilane, 13.0 parts by weight of 3-mercaptopropyltrimethoxysilane, and 2.5 parts by weight of 2,2'-azobis(2-methylbutyronitrile) dissolved in 22.7 parts by weight of isobutanol was added dropwise over 5 hours. Polymerization was further carried out at 105°C for 2 hours, yielding an isobutanol solution (solids content 60%) of a reactive silicon group-containing (meth)acrylic acid ester copolymer (B-3) having a number average molecular weight of 2,350 (GPC molecular weight). The solid content of the solution had a polyfunctional macromonomer equivalent of 0.13 mmol / g, a reactive silicon group equivalent of 0.42 mmol / g, and a sulfur atom content of 12574 ppm.

[0174] (Synthesis Example 9) A four-neck flask equipped with a stirrer was charged with 53.2 parts by weight of isobutanol, and the temperature was raised to 105° C. under a nitrogen atmosphere. A mixed solution prepared by dissolving 40.8 parts by weight of methyl methacrylate, 16.6 parts by weight of butyl acrylate, 0.3 parts by weight of 2-ethylhexyl acrylate, 0.3 parts by weight of stearyl methacrylate, 39.6 parts by weight of the multifunctional macromonomer (b2-3) prepared in Synthesis Example 5, 0.3 parts by weight of 3-methacryloxypropyltrimethoxysilane, 2.1 parts by weight of 3-mercaptopropyltrimethoxysilane, and 0.29 parts by weight of 2,2′-azobis(2-methylbutyronitrile) in 9.4 parts by weight of isobutanol was added dropwise thereto over 5 hours. 0.09 parts by weight of 2,2'-azobis(2-methylbutyronitrile) was dissolved in 2.9 parts by weight of isobutanol and added, and polymerization was carried out for 2 hours at 105°C to obtain an isobutanol solution (solids content 60%) of reactive silicon group-containing (meth)acrylic acid ester copolymer (B-4) with a number average molecular weight of 5,830 (GPC molecular weight). The solid content of this solution was 0.035 mmol / g of polyfunctional macromonomer equivalent, 0.12 mmol / g of reactive silicon group equivalent, and 3429 ppm of sulfur atom content.

[0175] (Synthesis Example 10) A four-neck flask equipped with a stirrer was charged with 53.2 parts by weight of isobutanol, and the temperature was raised to 105° C. under a nitrogen atmosphere. A mixed solution prepared by dissolving 51.5 parts by weight of methyl methacrylate, 21.0 parts by weight of butyl acrylate, 0.4 parts by weight of 2-ethylhexyl acrylate, 0.4 parts by weight of stearyl methacrylate, 25.0 parts by weight of the multifunctional macromonomer (b2-3) prepared in Synthesis Example 5, 0.4 parts by weight of 3-methacryloxypropyltrimethoxysilane, 1.3 parts by weight of 3-mercaptopropyltrimethoxysilane, and 0.37 parts by weight of 2,2′-azobis(2-methylbutyronitrile) in 11.9 parts by weight of isobutanol was added dropwise thereto over 5 hours. 0.11 parts by weight of 2,2'-azobis(2-methylbutyronitrile) was dissolved in 3.6 parts by weight of isobutanol and added, and polymerization was carried out for 2 hours at 105°C to obtain an isobutanol solution (solids content 60%) of reactive silicon group-containing (meth)acrylic acid ester copolymer (B-5) with a number average molecular weight of 9,700 (GPC molecular weight). The polyfunctional macromonomer equivalent of the solid content of this solution was 0.022 mmol / g, the reactive silicon group equivalent was 0.082 mmol / g, and the sulfur atom content was 2123 ppm.

[0176] (Synthesis Example 11) A four-necked flask equipped with a stirrer was charged with 48.0 parts by weight of isobutanol and heated to 105°C under a nitrogen atmosphere. A mixed solution of 50.0 parts by weight of methyl methacrylate, 7.0 parts by weight of butyl acrylate, 12.0 parts by weight of stearyl methacrylate, 30 parts by weight of the multifunctional macromonomer (b2-1) prepared in Synthesis Example 3, 1.0 parts by weight of 3-methacryloxypropyltrimethoxysilane, 7.2 parts by weight of 3-mercaptopropyltrimethoxysilane, and 2.5 parts by weight of 2,2'-azobis(2-methylbutyronitrile) dissolved in 22.7 parts by weight of isobutanol was added dropwise over 5 hours. Polymerization was further carried out at 105°C for 2 hours, yielding an isobutanol solution (solids content 60%) of a reactive silicon group-containing (meth)acrylic acid ester copolymer (B-6) having a number average molecular weight of 2,450 (GPC molecular weight). The solid content of the solution had a polyfunctional macromonomer equivalent of 0.069 mmol / g, a reactive silicon group equivalent of 0.38 mmol / g, and a sulfur atom content of 10941 ppm.

[0177] (Synthesis Example 12) A four-necked flask equipped with a stirrer was charged with 48.0 parts by weight of isobutanol and heated to 105°C under a nitrogen atmosphere. A mixed solution of 50.0 parts by weight of methyl methacrylate, 7.0 parts by weight of butyl acrylate, 12.0 parts by weight of stearyl methacrylate, 30 parts by weight of the multifunctional macromonomer (b2-2) prepared in Synthesis Example 4, 1.0 part by weight of 3-methacryloxypropyltrimethoxysilane, 7.2 parts by weight of 3-mercaptopropyltrimethoxysilane, and 2.5 parts by weight of 2,2'-azobis(2-methylbutyronitrile) dissolved in 22.7 parts by weight of isobutanol was added dropwise over 5 hours. Polymerization was further carried out at 105°C for 2 hours, yielding an isobutanol solution (solids content 60%) of a reactive silicon group-containing (meth)acrylic acid ester copolymer (B-7) having a number average molecular weight of 2,280 (GPC molecular weight). The solid content of the solution had a polyfunctional macromonomer equivalent of 0.033 mmol / g, a reactive silicon group equivalent of 0.38 mmol / g, and a sulfur atom content of 10941 ppm.

[0178] (Synthesis Example 13) A four-necked flask equipped with a stirrer was charged with 48.0 parts by weight of isobutanol and heated to 105°C under a nitrogen atmosphere. A mixed solution of 50.0 parts by weight of methyl methacrylate, 10.0 parts by weight of stearyl methacrylate, 30 parts by weight of the multifunctional macromonomer (b2-1) prepared in Synthesis Example 3, 10.0 parts by weight of 3-methacryloxypropyltrimethoxysilane, 7.2 parts by weight of 3-mercaptopropyltrimethoxysilane, and 2.5 parts by weight of 2,2'-azobis(2-methylbutyronitrile) dissolved in 22.7 parts by weight of isobutanol was added dropwise over 5 hours. Polymerization was further carried out at 105°C for 2 hours, yielding an isobutanol solution (solids content 60%) of a reactive silicon group-containing (meth)acrylic acid ester copolymer (B-8) having a number average molecular weight of 2,500 (GPC molecular weight). The solid content of the solution had a polyfunctional macromonomer equivalent of 0.069 mmol / g, a reactive silicon group equivalent of 0.72 mmol / g, and a sulfur atom content of 10941 ppm.

[0179] (Synthesis Example 14) A four-neck flask equipped with a stirrer was charged with 53.2 parts by weight of isobutanol, and the temperature was raised to 105° C. under a nitrogen atmosphere. A mixed solution prepared by dissolving 51.5 parts by weight of methyl methacrylate, 21.4 parts by weight of butyl acrylate, 0.4 parts by weight of 2-ethylhexyl acrylate, 0.4 parts by weight of stearyl methacrylate, 25.0 parts by weight of the multifunctional macromonomer (b2-3) prepared in Synthesis Example 5, 1.3 parts by weight of 3-mercaptopropyltrimethoxysilane, and 0.37 parts by weight of 2,2′-azobis(2-methylbutyronitrile) in 11.9 parts by weight of isobutanol was added dropwise thereto over 5 hours. 0.11 parts by weight of 2,2'-azobis(2-methylbutyronitrile) was dissolved in 3.6 parts by weight of isobutanol and added, and polymerization was carried out for 2 hours at 105°C to obtain an isobutanol solution (solids content 60%) of reactive silicon group-containing (meth)acrylic acid ester copolymer (B-9) with a number average molecular weight of 9,460 (GPC molecular weight). The solid content of this solution was 0.022 mmol / g of polyfunctional macromonomer equivalent, 0.066 mmol / g of reactive silicon group equivalent, and 2119 ppm of sulfur atom content.

[0180] (Synthesis Example 15) A four-neck flask equipped with a stirrer was charged with 53.2 parts by weight of isobutanol, and the temperature was raised to 105° C. under a nitrogen atmosphere. A mixed solution prepared by dissolving 51.5 parts by weight of methyl methacrylate, 18.8 parts by weight of butyl acrylate, 0.4 parts by weight of 2-ethylhexyl acrylate, 0.4 parts by weight of stearyl methacrylate, 25.0 parts by weight of the multifunctional macromonomer (b2-3) prepared in Synthesis Example 5, 2.6 parts by weight of 3-methacryloxypropyltrimethoxysilane, 1.4 parts by weight of n-dodecyl mercaptan, and 0.37 parts by weight of 2,2′-azobis(2-methylbutyronitrile) in 11.9 parts by weight of isobutanol was added dropwise thereto over 5 hours. 0.11 parts by weight of 2,2'-azobis(2-methylbutyronitrile) was dissolved in 3.6 parts by weight of isobutanol and added, and polymerization was carried out for 2 hours at 105°C to obtain an isobutanol solution (solids content 60%) of reactive silicon group-containing (meth)acrylic acid ester copolymer (B-10) with a number average molecular weight of 9,320 (GPC molecular weight). The solid content of this solution was 0.022 mmol / g of polyfunctional macromonomer equivalent, 0.10 mmol / g of reactive silicon group equivalent, and 2282 ppm of sulfur atom content.

[0181] (Synthesis Example 16) A four-neck flask equipped with a stirrer was charged with 47.2 parts by weight of isobutanol, and the temperature was raised to 105° C. under a nitrogen atmosphere. A mixed solution prepared by dissolving 33.9 parts by weight of methyl methacrylate, 0.3 parts by weight of butyl acrylate, 14.3 parts by weight of stearyl methacrylate, 38.5 parts by weight of the multifunctional macromonomer (b2-2) prepared in Synthesis Example 4, 6.4 parts by weight of 3-methacryloxypropyldimethoxymethylsilane, 6.4 parts by weight of 3-mercaptopropyldimethoxymethylsilane, and 0.3 parts by weight of 2,2′-azobis(2-methylbutyronitrile) in 11.3 parts by weight of isobutanol was added dropwise thereto over 5 hours. Furthermore, a mixed solution of 0.2 parts by weight of 2,2'-azobis(2-methylbutyronitrile) in 6.8 parts by weight of isobutanol was polymerized at 105°C for 2 hours to obtain an isobutanol solution (solids content 60%) of reactive silicon group-containing (meth)acrylic acid ester copolymer (B-11) with a number average molecular weight of 2,650 (GPC molecular weight). The solid content of this solution was 0.045 mmol / g of polyfunctional macromonomer equivalent, 0.63 mmol / g of reactive silicon group equivalent, and 11,424 ppm of sulfur atom content.

[0182] (Synthesis Example 17) A four-necked flask equipped with a stirrer was charged with 48.0 parts by weight of isobutanol and heated to 105°C under a nitrogen atmosphere. A mixed solution of 50.0 parts by weight of butyl acrylate, 10.0 parts by weight of stearyl methacrylate, 30 parts by weight of the multifunctional macromonomer (b2-1) prepared in Synthesis Example 3, 10.0 parts by weight of 3-methacryloxypropyltrimethoxysilane, and 2.5 parts by weight of 2,2'-azobis(2-methylbutyronitrile) dissolved in 22.7 parts by weight of isobutanol was added dropwise over 5 hours. Polymerization was continued for another 2 hours at 105°C to obtain an isobutanol solution (solids content 60%) of a reactive silicon group-containing (meth)acrylic acid ester copolymer (P-1) with a number average molecular weight of 6,950 (GPC molecular weight). The multifunctional macromonomer equivalent of the solids in this solution was 0.074 mmol / g, and the reactive silicon group equivalent was 0.40 mmol / g.

[0183] (Synthesis Example 18) A four-necked flask equipped with a stirrer was charged with 48.0 parts by weight of isobutanol and heated to 105°C under a nitrogen atmosphere. A mixed solution of 89.0 parts by weight of butyl acrylate, 10.0 parts by weight of stearyl methacrylate, 1.0 parts by weight of 3-methacryloxypropyltrimethoxysilane, 1.8 parts by weight of 3-mercaptopropyltrimethoxysilane, and 2.5 parts by weight of 2,2'-azobis(2-methylbutyronitrile) dissolved in 22.7 parts by weight of isobutanol was added dropwise over 5 hours. Polymerization was further carried out at 105°C for 2 hours, yielding an isobutanol solution (solids content 60%) of a reactive silicon group-containing (meth)acrylic acid ester copolymer (P-2) with a number average molecular weight of 3,730 (GPC molecular weight). The reactive silicon group equivalent of the solids in this solution was 0.13 mmol / g.

[0184] (Synthesis Example 19) A four-necked flask equipped with a stirrer was charged with 48.0 parts by weight of isobutanol, and the temperature was raised to 105°C under a nitrogen atmosphere. A mixed solution of 50.0 parts by weight of butyl acrylate, 10.0 parts by weight of stearyl methacrylate, 30 parts by weight of a polyoxyalkylene polymer (p-1) having a number average molecular weight of 4,800 (GPC molecular weight) and allyl groups at both ends, 10.0 parts by weight of 3-methacryloxypropyltrimethoxysilane, 7.2 parts by weight of 3-mercaptopropyltrimethoxysilane, and 2.5 parts by weight of 2,2'-azobis(2-methylbutyronitrile) dissolved in 22.7 parts by weight of isobutanol was added dropwise over 5 hours. Polymerization was further carried out at 105°C for 2 hours, yielding an isobutanol solution (solids content 60%) of a reactive silicon group-containing (meth)acrylic acid ester copolymer (P-3) having a number average molecular weight of 1,980 (GPC molecular weight). The reactive silicon group equivalent of the solid content of the solution is 0.72 mmol / g.

[0185] (Synthesis Example 20) A four-neck flask equipped with a stirrer was charged with 44.5 parts by weight of isobutanol, and the temperature was raised to 105° C. under a nitrogen atmosphere. A mixed solution prepared by dissolving 40.8 parts by weight of methyl methacrylate, 54.2 parts by weight of butyl acrylate, 0.5 parts by weight of 2-ethylhexyl acrylate, 0.5 parts by weight of stearyl methacrylate, 0.5 parts by weight of 3-methacryloxypropyltrimethoxysilane, 1.3 parts by weight of 3-mercaptopropyltrimethoxysilane, and 0.37 parts by weight of 2,2′-azobis(2-methylbutyronitrile) in 11.9 parts by weight of isobutanol was added dropwise thereto over 5 hours. 0.11 parts by weight of 2,2'-azobis(2-methylbutyronitrile) was dissolved in 3.6 parts by weight of isobutanol and added, and polymerization was carried out at 105°C for 2 hours to obtain an isobutanol solution (solids content 60%) of reactive silicon group-containing (meth)acrylic acid ester copolymer (P-4) with a number average molecular weight of 9,700 (GPC molecular weight). The reactive silicon group equivalent of this solution was 0.20 mmol / g, and the sulfur atom content was 5716 ppm.

[0186] (Synthesis Example 21) A four-necked flask equipped with a stirrer was charged with 48.0 parts by weight of isobutanol and heated to 105°C under a nitrogen atmosphere. A mixed solution of 50.0 parts by weight of methyl methacrylate, 37.0 parts by weight of butyl acrylate, 12.0 parts by weight of stearyl methacrylate, 1.0 parts by weight of 3-methacryloxypropyltrimethoxysilane, 7.2 parts by weight of 3-mercaptopropyltrimethoxysilane, and 2.5 parts by weight of 2,2'-azobis(2-methylbutyronitrile) dissolved in 22.7 parts by weight of isobutanol was added dropwise over 5 hours. Polymerization was further carried out at 105°C for 2 hours, yielding an isobutanol solution (solids content 60%) of a reactive silicon group-containing (meth)acrylic acid ester copolymer (P-5) with a number average molecular weight of 2,190 (GPC molecular weight). The reactive silicon group equivalent of the solids in this solution was 0.38 mmol / g.

[0187] (Synthesis Example 22) A four-necked flask equipped with a stirrer was charged with 48.0 parts by weight of isobutanol and heated to 105°C under a nitrogen atmosphere. A mixed solution of 50.0 parts by weight of methyl methacrylate, 30.0 parts by weight of butyl acrylate, 10.0 parts by weight of stearyl methacrylate, 10.0 parts by weight of 3-methacryloxypropyltrimethoxysilane, 7.2 parts by weight of 3-mercaptopropyltrimethoxysilane, and 2.5 parts by weight of 2,2'-azobis(2-methylbutyronitrile) dissolved in 22.7 parts by weight of isobutanol was added dropwise over 5 hours. Polymerization was further carried out at 105°C for 2 hours, yielding an isobutanol solution (solids content 60%) of a reactive silicon group-containing (meth)acrylic acid ester copolymer (P-6) with a number average molecular weight of 2,230 (GPC molecular weight). The reactive silicon group equivalent of the solids in this solution was 0.72 mmol / g.

[0188] (Synthesis Example 23) A four-necked flask equipped with a stirrer was charged with 48.0 parts by weight of isobutanol and heated to 105°C under a nitrogen atmosphere. A mixed solution of 50.0 parts by weight of methyl methacrylate, 30.0 parts by weight of butyl acrylate, 10.0 parts by weight of stearyl methacrylate, 10.0 parts by weight of 3-methacryloxypropyltrimethoxysilane, 1.8 parts by weight of 3-mercaptopropyltrimethoxysilane, and 2.5 parts by weight of 2,2'-azobis(2-methylbutyronitrile) dissolved in 22.7 parts by weight of isobutanol was added dropwise over 5 hours. Polymerization was further carried out at 105°C for 2 hours, yielding an isobutanol solution (solids content 60%) of a reactive silicon group-containing (meth)acrylic acid ester copolymer (P-7) with a number average molecular weight of 4,100 (GPC molecular weight). The reactive silicon group equivalent of the solids in this solution was 0.49 mmol / g.

[0189] (Synthesis Example 24) 0.42 parts by weight of cuprous bromide and 20.0 parts by weight of butyl acrylate were added to a deoxygenated reactor and heated with stirring. 8.8 parts by weight of acetonitrile as the polymerization solvent and 5.07 parts by weight of ethyl 2-bromoadipate as the initiator were added and mixed. The temperature of the mixture was adjusted to approximately 80°C, and pentamethyldiethylenetriamine (hereinafter referred to as triamine) was added to initiate the polymerization reaction. Next, 80.0 parts by weight of butyl acrylate was gradually added to proceed with the polymerization reaction. During the polymerization, additional triamine was added as needed to adjust the polymerization rate. The total amount of triamine used during the polymerization was 0.15 parts by weight. When the monomer conversion rate (polymerization reaction rate) reached approximately 95% or higher, volatile matter was removed by devolatilization under reduced pressure to obtain a polymer concentrate. The concentrate was diluted with toluene, and a filter aid, an adsorbent (Kyoward 700SEN, manufactured by Kyowa Chemical Industry Co., Ltd.), and hydrotalcite (Kyoward 500SH, manufactured by Kyowa Chemical Industry Co., Ltd.) were added. The mixture was heated and stirred at about 80 to 100°C, and the solid components were removed by filtration. The filtrate was concentrated under reduced pressure to obtain a crude polymer. The crude polymer, 4.91 parts by weight of potassium acrylate, 100 ppm of 4-hydroxy-TEMPO, and 100 parts by weight of dimethylacetamide as a solvent were added and reacted at 70°C for 3 hours. The solvent was then removed by distillation under reduced pressure to obtain a polymer concentrate. The concentrate was diluted with toluene, and the solid components were removed by filtration. The filtrate was concentrated under reduced pressure to obtain macromonomer (p-2) with an acryloyl group at one end (i.e., one acryloyl group per polymer molecule), a number average molecular weight of 4,040 (GPC molecular weight), and a molecular weight distribution (Mw / Mn) of 1.18.

[0190] (Synthesis Example 25) A four-necked flask equipped with a stirrer was charged with 48.0 parts by weight of isobutanol and heated to 105°C under a nitrogen atmosphere. A mixed solution of 50.0 parts by weight of butyl acrylate, 10.0 parts by weight of stearyl methacrylate, 30 parts by weight of the macromonomer (p-2) having one acryloyl group per molecule prepared in Synthesis Example 24, 10.0 parts by weight of 3-methacryloxypropyltrimethoxysilane, and 2.5 parts by weight of 2,2'-azobis(2-methylbutyronitrile) dissolved in 22.7 parts by weight of isobutanol was added dropwise over 5 hours. Polymerization was continued for another 2 hours at 105°C to obtain an isobutanol solution (solids content 60%) of a reactive silicon group-containing (meth)acrylic acid ester copolymer (P-8) with a number average molecular weight of 1,900 (GPC molecular weight). The macromonomer equivalent of the solids in this solution was 0.069 mmol / g, and the reactive silicon group equivalent was 0.72 mmol / g.

[0191] (Synthesis Example 26) A four-necked flask equipped with a stirrer was charged with 47.2 parts by weight of isobutanol and heated to 105°C under a nitrogen atmosphere. A mixed solution of 33.9 parts by weight of methyl methacrylate, 38.8 parts by weight of butyl acrylate, 14.3 parts by weight of stearyl methacrylate, 6.4 parts by weight of 3-methacryloxypropyldimethoxymethylsilane, 6.4 parts by weight of 3-mercaptopropyldimethoxymethylsilane, and 0.3 parts by weight of 2,2'-azobis(2-methylbutyronitrile) dissolved in 11.3 parts by weight of isobutanol was added dropwise over 5 hours. A mixed solution of 0.2 parts by weight of 2,2'-azobis(2-methylbutyronitrile) dissolved in 6.8 parts by weight of isobutanol was 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 copolymer (P-9) having a number average molecular weight of 2300 (GPC molecular weight). The reactive silicon group equivalent of the solid content of the solution is 0.63 mmol / g.

[0192] First, isobutanol was heated and volatilized off from the isobutanol solutions of the (meth)acrylic acid ester copolymers (B-1) to (B-3) obtained in Synthesis Examples 6 to 8 and the isobutanol solutions of the (meth)acrylic acid ester copolymers (P-1) to (P-3) obtained in Synthesis Examples 17 to 19, and the viscosity of each of the resulting polymers was measured by the following method.

[0193] (viscosity) A 25 mm diameter cone plate (2°) was used as a jig, the gap was set to 60 μm, and the rotation speed was 0.1 sec -1 The viscosity of each polymer was measured at this time. A TA Instruments rheometer (ARES-G2) was used. The results are shown in Table 1.

[0194] [Table 1]

[0195] As shown in Table 1, the (meth)acrylic acid ester copolymers (B-1) to (B-3) formed by copolymerizing both a polyfunctional macromonomer (b2), which is a (meth)acrylic acid ester polymer having more than one (meth)acryloyl group per molecule, and a chain transfer agent (b3) having a mercapto group have narrower molecular weight distributions and lower viscosities than the (meth)acrylic acid ester copolymer (P-1) formed without using the chain transfer agent (b3) having a mercapto group.

[0196] On the other hand, in the case of the (meth)acrylic acid ester copolymer (P-3) formed by using an allyl group-containing polyoxyalkylene polymer (p-1) instead of the (meth)acryloyl group-containing (meth)acrylic acid ester polymer (b2-1), judging from its weight average molecular weight (Mw), it is clear that the copolymerization of (p-1) has hardly progressed. That is, it is understood that the (meth)acrylic acid ester copolymers (B-1) to (B-3) have a narrow molecular weight distribution and a low viscosity, even though the copolymerization of the polyfunctional macromonomer (b2) has progressed.

[0197] The (meth)acrylic acid ester copolymers (B-1) to (B-3) are formed by copolymerizing the multifunctional macromonomer (b2) with butyl acrylate or the like to form block copolymers. On the other hand, the (meth)acrylic acid ester copolymer (P-2) is a random copolymer because it does not use the multifunctional macromonomer (b2). Table 1 shows that the (meth)acrylic acid ester copolymers (B-1) to (B-3) have lower viscosities relative to the weight-average molecular weight (Mw) compared to the (meth)acrylic acid ester copolymer (P-2). For example, even though (B-1) and (P-2) have similar weight-average molecular weights, the viscosity of (B-1) is about half that of (P-2).

[0198] (Tensile properties) 100 parts by weight of the solid content of each polymer solution was mixed with 1 part by weight of Neostan U-20 (dibutyltin dibutyl maleate, manufactured by Nitto Kasei Co., Ltd.) as a curing catalyst to prepare a 100 μm-thick sheet. The resulting sheet was cured and aged for two weeks at 23°C and 50% RH. 70 mm x 10 mm strip test pieces were cut from the resulting sheet, and the tensile properties were measured at 23°C with a gripper distance of 40 mm. The stress at 30% elongation (M30), strength at break (TB), elongation at break (EB), and Young's modulus were measured. The tensile properties were measured using an autograph (AGS-X) manufactured by Shimadzu Corporation at a pulling rate of 20 mm / min. The results are shown in Table 2.

[0199] [Table 2]

[0200] As shown in Table 2, the (meth)acrylic acid ester copolymer (P-4), which was produced without using the polyfunctional macromonomer (b2), gave a cured product that was too soft to prepare test specimens. However, the cured products obtained from the (meth)acrylic acid ester copolymers (B-4) to (B-5) and (B-9) to (B-10), which were produced by copolymerizing the polyfunctional macromonomer (b2), showed good tensile properties.

[0201] Next, 60 parts by weight of the polyoxypropylene polymer (A-1) obtained in Synthesis Example 1 was mixed with an isobutanol solution of the (meth)acrylic acid ester copolymers (B-6) to (B-8) or (P-5) to (P-8) obtained in Synthesis Examples 11 to 13, 21 to 23, and 25 so that the solids concentration was 40 parts by weight, and the isobutanol was heated to devolatilize, and the viscosity of each mixture was measured by the method described above. The results are shown in Table 3.

[0202] [Table 3]

[0203] As shown in Table 3, the mixture containing the polyoxyalkylene polymer (A) and the (meth)acrylic acid ester copolymer (B) has a lower viscosity relative to the weight average molecular weight (Mw) than the mixture containing the (meth)acrylic acid ester copolymer (P) instead of the (meth)acrylic acid ester copolymer (B).

[0204] Specifically, the mixtures containing (meth)acrylic acid ester copolymers (B-6) to (B-8) have a weight-average molecular weight that is about twice as high as that of the mixtures containing (meth)acrylic acid ester copolymers (P-5) or (P-6) formed without using the polyfunctional macromonomer (b2), but the increase in viscosity is only about 1.5 times. Furthermore, the mixtures containing (meth)acrylic acid ester copolymers (B-6) to (B-8) have a viscosity that is significantly lower, about 50 to 60%, than the mixture containing (meth)acrylic acid ester copolymer (P-7) formed without using the polyfunctional macromonomer (b2) and having a slightly higher weight-average molecular weight.

[0205] Furthermore, the mixtures containing the (meth)acrylic acid ester copolymers (B-6) to (B-8) have a weight-average molecular weight that is approximately twice as large as that of the mixture containing the (meth)acrylic acid ester copolymer (P-8) formed using a monomer (p-2) having only one (meth)acryloyl group per molecule instead of the polyfunctional macromonomer (b2), but the increase in viscosity is only about 1.5 times.

[0206] Example 1 60 parts by weight of the reactive silicon group-containing polyoxypropylene polymer (A-1) obtained in Synthesis Example 1 and the isobutanol solution of the (meth)acrylic acid ester copolymer (B-6) obtained in Synthesis Example 11 were mixed so that the solid content was 40 parts by weight, and the isobutanol was then heated to remove the volatiles. The resulting mixture was mixed with 40 parts by weight of Nanox #30 (heavy calcium carbonate, manufactured by Maruo Calcium Co., Ltd.) as a filler, 30 parts by weight of CCR-S10 (synthetic calcium carbonate, manufactured by Shiraishi Calcium Co., Ltd.), 20 parts by weight of Actocol P-23 (polypropylene glycol, manufactured by Mitsui Chemicals, Inc.) as a plasticizer, 2.5 parts by weight of Disparlon 6500 (fatty acid amide wax, manufactured by Kusumoto Chemical Co., Ltd.) as a thixotropic agent, 1 part by weight of Nocrac CD (4,4'-bis(α,α-dimethylbenzyl)diphenylamine, manufactured by Ouchi Shinko Chemical Industry Co., Ltd.) as an antioxidant, and 1 part by weight of Adekastab AO-60 (pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, manufactured by ADEKA Corporation) using a planetary mixer, and the mixture was dehydrated by heating under reduced pressure at 120°C for 1 hour. The resulting composition was cooled and mixed with 3 parts by weight of A-171 (vinyltrimethoxysilane Momentive) as a dehydrating agent, 3 parts by weight of KBM-603 (N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, manufactured by Shin-Etsu Chemical Co., Ltd.) as an adhesion promoter, and 0.3 parts by weight of Neostan U-810 (dioctyltin dilaurate, manufactured by Nitto Kasei Co., Ltd.) as a curing catalyst to obtain a one-component curable composition.

[0207] (viscosity) The viscosity of the obtained one-component curable composition was measured using a parallel circular plate having a diameter of 25 mm as a jig, with a gap set to 0.5 mm and a rotation speed of 0.2 sec. -1 or 10 seconds -1 The measurement was performed using a TA Instruments rheometer (ARES-G2). The viscosity ratio was (0.2 sec -1 Viscosity at / 10sec -1 The results are shown in Table 4.

[0208] (Tensile properties) The resulting one-component curable composition was used to prepare a sheet approximately 2 mm thick. The sheet was cured and aged for 3 days at 23°C and 50% RH, followed by 4 days at 50°C. The resulting sheet was punched into a No. 3 dumbbell shape (JIS K 6251) and subjected to a tensile strength test at 23°C and 50% RH to measure the stress at 50% elongation (M50) and the strength at break (TB). Tensile properties were measured at a pulling rate of 200 mm / min using an autograph (AGS-X) manufactured by Shimadzu Corporation. The results are shown in Table 4.

[0209] (shear adhesive strength) Steel plates (SS400) used as adherends were polished with #400 sandpaper. A one-component curable composition was applied to a bond area of ​​25 mm x 12.5 mm and a thickness of 0.5 mm, and the adherends were then bonded together. Starting from the time of bonding, the specimens were cured at 23°C and 50% RH for 7 days, followed by 4 days at 50°C. The shear bond strength was measured at a test speed of 10 mm / min, and the failure state was observed. Cohesive failure (failure at the adhesive) was designated CF, and interfacial failure (peel at the interface between the adhesive and the adherend) was designated AF. When both types of failure were present, the respective percentages were recorded. For example, a cohesive failure rate of 50% and an interfacial failure rate of 50% were recorded as C50A50. The results are shown in Table 4.

[0210] (Example 2 and Comparative Example 1) One-component curable compositions were prepared in the same manner as in Example 1, except that the formulation was changed as shown in Table 4, and the viscosity, tensile properties, and shear adhesive strength were evaluated. The results are shown in Table 4.

[0211] [Table 4]

[0212] A comparison of Examples 1 and 2 with Comparative Example 1 in Table 4 reveals that the compositions of the examples containing the polyoxyalkylene polymer (A) and the (meth)acrylic acid ester copolymer (B) give cured products with higher tensile strength and shear adhesive strength than the comparative example composition containing the (meth)acrylic acid ester copolymer (P-5) formed without using the polyfunctional macromonomer (b2) instead of the (meth)acrylic acid ester copolymer (B).

[0213] Furthermore, it can be seen that the composition of Example 1, which contains a (meth)acrylic acid ester copolymer (B-6) in which a small amount of 3-methacryloxypropyltrimethoxysilane, the monomer (b4) having a reactive silicon group and a polymerizable unsaturated group, is used, has a larger viscosity ratio, i.e., a higher thixotropy, than the composition of Example 3 described below, which contains a (meth)acrylic acid ester copolymer (B-8) in which a large amount of 3-methacryloxypropyltrimethoxysilane is used.

[0214] (Example 3 and Comparative Example 2) One-component curable compositions were prepared in the same manner as in Example 1, except that the formulation was changed as shown in Table 5, and the viscosity, tensile properties, and shear adhesive strength were evaluated. The results are shown in Table 5.

[0215] [Table 5]

[0216] A comparison between Example 3 and Comparative Example 2 in Table 5 reveals that the composition of Example 3, which contains the polyoxyalkylene polymer (A) and the (meth)acrylic acid ester copolymer (B), gives a cured product with higher tensile strength and shear adhesive strength than the composition of Comparative Example 2, which contains the (meth)acrylic acid ester copolymer (P-6) formed without using the polyfunctional macromonomer (b2) instead of the (meth)acrylic acid ester copolymer (B).

[0217] (Example 4 and Comparative Example 3) One-component curable compositions were prepared in the same manner as in Example 1, except that the formulation was changed as shown in Table 6, and the tensile properties were evaluated. The results are shown in Table 6.

[0218] [Table 6]

[0219] A comparison between Example 4 and Comparative Example 3 in Table 6 reveals that the composition of Example 4, which contains the polyoxyalkylene polymer (A) and the (meth)acrylic acid ester copolymer (B), gives a cured product with higher tensile strength than the composition of Comparative Example 3, which contains the (meth)acrylic acid ester copolymer (P-9) formed without using the polyfunctional macromonomer (b2) instead of the (meth)acrylic acid ester copolymer (B).

Claims

1. A (meth)acrylic acid ester copolymer (B) having a reactive silicon group represented by general formula (1), The monomer components constituting the copolymer are (meth)acrylic acid ester (b1), a (meth)acrylic acid ester-based polymer (b2) having more than 1 and not more than 2.0 (meth)acryloyl groups in the molecule; and a chain transfer agent (b3) having a mercapto group, and the monomer component further contains a monomer (b4) having a reactive silicon group and a polymerizable unsaturated group, and / or the chain transfer agent (b3) having a mercapto group further contains a reactive silicon group; the monomer component forming the main chain skeleton of the (meth)acrylic acid ester-based polymer (b2) contains 60% by weight or more of an acrylic acid ester (excluding isobornyl acrylate, dicyclopentenyl acrylate, and dicyclopentanyl acrylate); The (meth)acrylic acid ester copolymer (B) has a content of the (meth)acrylic acid ester polymer (b2) of 1 to 60% by weight based on the total amount of monomer components constituting the (meth)acrylic acid ester copolymer (B). -SiR ５ ｃ X ３－ｃ (1) (In the formula, R ５ is a substituted or unsubstituted hydrocarbon group having 1 to 20 carbon atoms. X represents a hydroxyl group or a hydrolyzable group. c represents 0 or 1.

2. The (meth)acrylic acid ester copolymer (B) according to claim 1, wherein the (meth)acrylic acid ester polymer (b2) accounts for 0.2 mol % or more and 5.0 mol % or less of the monomer components.

3. The (meth)acrylic acid ester-based copolymer (B) according to claim 1 or 2, wherein the chain transfer agent (b3) having a mercapto group accounts for 0.4 mol % or more and 15 mol % or less of the monomer component.

4. The (meth)acrylic acid ester copolymer (B) according to any one of claims 1 to 3, wherein the (meth)acrylic acid ester polymer (b2) has a number average molecular weight of 500 or more and 50,000 or less.

5. The (meth)acrylic acid ester copolymer (B) according to any one of claims 1 to 4, wherein the (meth)acrylic acid ester copolymer (B) has a weight average molecular weight of 80,000 or less.

6. The (meth)acrylic acid ester copolymer (B) according to any one of claims 1 to 5, wherein the molecular weight distribution of the (meth)acrylic acid ester copolymer (B) is 3.0 or more and 11.0 or less.

7. The (meth)acrylic acid ester-based copolymer (B) according to any one of claims 1 to 6, wherein a molar ratio of the (meth)acrylic acid ester-based polymer (b2) to the chain transfer agent (b3) having a mercapto group is 0.12 or more and 0.58 or less.

8. A (meth)acrylic acid ester copolymer (B) having a reactive silicon group represented by general formula (1), the copolymer has a structure in which two first molecular chains are bonded via one second molecular chain, and both ends of the second molecular chain are bonded to non-terminal portions of the first molecular chain, the first molecular chain and the second molecular chain are each composed of a molecular chain of a (meth)acrylic acid ester copolymer; the reactive silicon group is bonded to a first molecular chain, the first molecular chain has a structure represented by -S-R (wherein S represents a sulfur atom and R represents the hydrocarbon group optionally having a reactive silicon group) at either end, a proportion of acrylic acid esters (excluding isobornyl acrylate, dicyclopentenyl acrylate, and dicyclopentanyl acrylate) in the monomer components constituting the second molecular chain is 60% by weight or more; The content of the second molecular chains is 1 to 60% by weight based on the total amount of the (meth)acrylic acid ester copolymer (B). -SiR ５ ｃ X ３－ｃ (1) (In the formula, R ５ is a substituted or unsubstituted hydrocarbon group having 1 to 20 carbon atoms. X represents a hydroxyl group or a hydrolyzable group. c represents 0 or 1.

9. The (meth)acrylic acid ester-based copolymer (B) according to claim 8, wherein the monomer component constituting the first molecular chain contains at least one monomer selected from the group consisting of methacrylic acid esters, isobornyl acrylate, dicyclopentenyl acrylate, and dicyclopentanyl acrylate.

10. 10. The (meth)acrylic acid ester-based copolymer (B) according to claim 9, wherein, among the monomer components constituting the first molecular chain, at least one monomer selected from the group consisting of methacrylic acid esters, isobornyl acrylate, dicyclopentenyl acrylate, and dicyclopentanyl acrylate accounts for 60% by weight or more.

11. The (meth)acrylic acid ester-based copolymer (B) according to any one of claims 8 to 10, wherein the sulfur atom concentration in the (meth)acrylic acid ester-based copolymer (B) is 700 ppm or more and 20,000 ppm or less.

12. A curable composition comprising the (meth)acrylic acid ester copolymer (B) according to any one of claims 1 to 11.

13. The curable composition according to claim 12, further comprising a polyoxyalkylene polymer (A) having a reactive silicon group represented by general formula (1):

14. The polyoxyalkylene polymer (A) is represented by the general formula (2): 【Chemical 1】 (Wherein R 1 represents CH 2 OCH 2 , R 3 represents CH 2 . R ２ , R ４ are each independently hydrogen or a hydrocarbon group having 1 to 10 carbon atoms. n is an integer of 1 to 10. R ５ is a substituted or unsubstituted hydrocarbon group having 1 to 20 carbon atoms; X is a hydroxyl group or a hydrolyzable group; and c is 0 or 1. The curable composition according to claim 13, having a terminal structure represented by the following formula:

15. A cured product of the curable composition according to any one of claims 12 to 14.

16. A method for producing a (meth)acrylic acid ester copolymer (B) having a reactive silicon group represented by general formula (1), comprising the steps of: copolymerizing the monomer components; The monomer component is (meth)acrylic acid ester (b1), a (meth)acrylic acid ester-based polymer (b2) having more than 1 and not more than 2.0 (meth)acryloyl groups in the molecule; and a chain transfer agent (b3) having a mercapto group, and the monomer component further contains a monomer (b4) having a reactive silicon group and a polymerizable unsaturated group, and / or the chain transfer agent (b3) having a mercapto group further contains a reactive silicon group; the monomer component forming the main chain skeleton of the (meth)acrylic acid ester-based polymer (b2) contains 60% by weight or more of an acrylic acid ester (excluding isobornyl acrylate, dicyclopentenyl acrylate, and dicyclopentanyl acrylate); The production method, wherein the content of the (meth)acrylic acid ester polymer (b2) is 1 to 60% by weight based on the total amount of the monomer components constituting the (meth)acrylic acid ester copolymer (B). -SiR ５ ｃ X ３－ｃ (1) (In the formula, R ５ is a substituted or unsubstituted hydrocarbon group having 1 to 20 carbon atoms. X represents a hydroxyl group or a hydrolyzable group. c represents 0 or 1.

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