Curable composition

Abstract

The curable composition contains 100 wt parts of a graft copolymer (P) in which (meth)acrylic acid ester polymer blocks (A) having a reactive silicon group, represented by the formula: -SiR1 3-aXa (in the formula, R1 represents a substituted or unsubstituted C1-20 hydrocarbon group. X represents a hydroxyl group or a hydrolyzable group. a represents 2 or 3.) and polyoxyalkylene polymer blocks (B) having a number average molecular weight of 1,000 or more are arranged in an A-B-A order and 5-65 wt parts of a (meth)acrylic acid ester polymer (Q) having a reactive silicon group represented by the above formula (1).

Description

curable composition

[0001] The present invention relates to a curable composition comprising a graft copolymer having a reactive silicon group.

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

[0003] As one example of an organic polymer having such reactive silicon groups, Patent Document 1 discloses a graft copolymer having reactive silicon groups, obtained by reacting a (meth)acrylic acid ester with a polyoxyalkylene polymer having one or more (meth)acryloyl groups in its molecule and a chain transfer agent having mercapto groups. This graft copolymer is composed of three polymer blocks bonded together.

[0004] The aforementioned patent document discloses that a curable composition containing the graft copolymer and a tackifying resin can be used as a hot-melt type curable composition. A hot-melt type curable composition is solid at room temperature but becomes fluid when heated and melted, allowing it to be applied to a substrate.

[0005] Although this does not relate to such a hot-melt type curable composition, Patent Document 2 describes a curable composition containing a reactive silicon group-containing graft copolymer similar to that in Patent Document 1 and a polyoxyalkylene polymer having reactive silicon groups in a weight ratio of 5:95 to 50:50.

[0006] International Publication No. 2023 / 132324, International Publication No. 2022 / 203065

[0007] Hot-melt curable compositions are solid at room temperature, but are heated and melted, applied to a substrate, and then cured to form a cured product. From the viewpoint of workability when applying to a substrate, it is desirable that the viscosity when heated and melted be low.

[0008] On the other hand, the cured material obtained by hardening is sometimes required to exhibit good elongation. However, reducing the melt viscosity can degrade the mechanical properties after hardening, particularly reducing elongation significantly.

[0009] In view of the above situation, the present invention aims to provide a curable composition comprising a reactive silicon group-containing graft copolymer that can exhibit low viscosity when heated and melted while maintaining elongation after curing.

[0010] As a result of diligent research to solve the above problems, the present inventors have found that the above problems can be solved by blending a specific amount of a reactive silicon group-containing (meth)acrylic acid ester polymer with a reactive silicon group-containing graft copolymer, and have completed the present invention.

[0011] In other words, the present invention relates to the general formula (1): -SiR １ ３－ａ X ａ (1) (wherein, R １ The present invention relates to a curable composition containing 100 parts by weight of a graft copolymer (P) in which a (meth)acrylic acid ester polymer block (A) having a reactive silicon group represented by the general formula (1) and a polyoxyalkylene polymer block (B) having a number average molecular weight of 1,000 or more are bonded in the order A-B-A, and 5 to 65 parts by weight of a (meth)acrylic acid ester polymer (Q) having a reactive silicon group represented by the general formula (1). The present invention also relates to a hot-melt type curable composition containing the above curable composition. Furthermore, the present invention also relates to a cured product obtained by curing the above curable composition.

[0012] According to the present invention, it is possible to provide a curable composition comprising a reactive silicon group-containing graft copolymer that can exhibit low viscosity when heated and melted while maintaining elongation after curing.

[0013] The curable composition according to the present invention is solid at room temperature, and is fluidized by heating and melting, enabling application to a substrate. After application, it cools and solidifies, and a curing reaction proceeds via hydrolysis and condensation reactions of reactive silicon groups, whereby a cured product can be formed.

[0014] Conceptual diagram of an H-type structure that may be contained in the graft copolymer (P)

[0015] Embodiments of the present invention are described in detail below. However, the present invention is not limited to the embodiments described below, and various modifications can be made within the scope defined in the claims. In addition, the configurations described below can be arbitrarily combined, and such combinations may also constitute an aspect of the present invention.

[0016] The curable composition according to the present disclosure contains at least a graft copolymer (P) having a reactive silicon group, and a (meth)acrylic acid ester-based polymer (Q) having a reactive silicon group. The curable composition is solid at room temperature (23°C), and is fluidized by heating and melting, enabling application to a substrate.

[0017] <Graft Copolymer (P)> The graft copolymer (P) according to the present disclosure is formed by bonding a (meth)acrylic acid ester-based polymer block (A) and a polyoxyalkylene-based polymer block (B). The graft copolymer (P) has a reactive silicon group, and the reactive silicon group is bonded to the polymer block (A). In the present application, "(meth)acrylic" means "acrylic and / or methacrylic".

[0018] <Reactive Silicon Group> The (meth)acrylic acid ester-based polymer block (A) has a reactive silicon group represented by the following general formula (1) at the molecular chain end and / or side chain (non-terminal site). -SiR １ ３－ａ X ａ (1) (wherein R １ represents a substituted or unsubstituted hydrocarbon group having 1 to 20 carbon atoms. X represents a hydroxyl group or a hydrolyzable group. a represents 2 or 3.)

[0019] R １The 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. R １ Specific examples thereof include a methyl group, an ethyl group, a chloromethyl group, a methoxymethyl group, and an N,N-diethylaminomethyl group. Preferred are a methyl group, an ethyl group, a chloromethyl group, and a methoxymethyl group, and more preferred are a methyl group and a methoxymethyl group.

[0020] Examples of X include a hydroxyl group, 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, and an alkenyloxy group. Among these, alkoxy groups are more preferred because of their mild hydrolyzability and ease of handling, and methoxy groups and ethoxy groups are particularly preferred.

[0021] a in formula (1) represents 2 or 3. In the reactive silicon group contained in the graft copolymer (P), a is preferably 3 because the effect of reducing the melt viscosity of the curable composition by blending the reactive silicon group-containing (meth)acrylic acid ester-based polymer (Q) is more favorable, and the effect of maintaining elongation after curing is also more favorable.

[0022] Specific examples of said reactive silicon groups 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, a (N,N-diethylaminomethyl)dimethoxysilyl group, and a (N,N-diethylaminomethyl)diethoxysilyl group. Among these, a methyldimethoxysilyl group, a trimethoxysilyl group, a triethoxysilyl group, a (chloromethyl)dimethoxysilyl group, a (methoxymethyl)dimethoxysilyl group, a (methoxymethyl)diethoxysilyl group, and a (N,N-diethylaminomethyl)dimethoxysilyl group are preferred because they exhibit high activity and provide a cured product having favorable mechanical properties.

[0023] Among the reactive silicon groups in the graft copolymer (P), trimethoxysilyl groups and triethoxysilyl groups are particularly preferred, with trimethoxysilyl groups being the most preferred, because they exhibit a better effect in reducing the melt viscosity of the curable composition by incorporating a reactive silicon group-containing (meth)acrylic acid ester polymer (Q), and also exhibit a better effect in maintaining elongation after curing.

[0024] The reactive silicon group equivalent of the graft copolymer (P) is preferably 0.1 to 0.45 mmol / g, more preferably 0.2 mmol / g or more, and even more preferably 0.3 mmol / g or more, from the viewpoint of obtaining a cured product with good strength and elongation. Furthermore, the reactive silicon group equivalent is preferably 0.4 mmol / g or less.

[0025] The reactive silicon group equivalent of the graft copolymer (P) is calculated by dividing the total silicon group equivalent of the reactive silicon group-containing components constituting the graft copolymer (P) by the total weight of the components constituting the graft copolymer (P). Specifically, it can be calculated by dividing the total silicon group equivalent, which is the sum of the silicon equivalent of the (meth)acrylic acid ester (a1-2) having reactive silicon groups and the silicon equivalent of the chain transfer agent (a2) having reactive silicon groups, by the total weight of the monomers and chain transfer agent constituting the graft copolymer (P).

[0026] <(meth)acrylic acid ester polymer block (A)> The (meth)acrylic acid ester polymer block (A) is a polymer block that contains at least one constituent unit derived from (meth)acrylic acid ester (a1).

[0027] <(meth)acrylic acid ester (a1)> (meth)acrylic acid ester (a1) is broadly classified into (meth)acrylic acid ester (a1-1) which does not have a reactive silicon group and (meth)acrylic acid ester (a1-2) which has a reactive silicon group. The (meth)acrylate ester (a1-1) that does not have a reactive silicon group is not particularly limited, but examples 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- Examples include hydroxypropyl, 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-perfluorobutyl ethyl (meth)acrylate, trifluoromethyl (meth)acrylate, perfluoroethyl (meth)acrylate, bis(trifluoromethyl)methyl (meth)acrylate, 2-trifluoromethyl-2-perfluoroethyl ethyl (meth)acrylate, 2-perfluorohexyl ethyl (meth)acrylate, 2-perfluorodecyl ethyl (meth)acrylate, 2-perfluorohexadecyl ethyl (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.As the (meth)acrylic acid ester (a1-1) that does not have a reactive silicon group, alkyl (meth)acrylic acid esters are preferred.

[0028] The content of (meth)acrylic acid ester (a1-1) without reactive silicon groups is preferably 30% by weight or more, more preferably 40% by weight or more, of the total amount of constituent units forming the (meth)acrylic acid ester polymer block (A), from the viewpoint of achieving both low melt viscosity and high elongation after curing. The upper limit is preferably 90% by weight or less, more preferably 85% by weight or less, and even more preferably 80% by weight or less.

[0029] It is preferable not to use alkyl (meth)acrylate esters having 10 to 30 C10 in the alkyl group as the (meth)acrylate ester (a1-1) that does not have reactive silicon groups. If it is used, it is preferable to set the content to a relatively small amount. This makes it possible to improve compatibility with the reactive silicon group-containing (meth)acrylate ester polymer (Q), reduce the melt viscosity of the curable composition, and obtain a cured product with good mechanical properties.

[0030] Specifically, the content of alkyl (meth)acrylate ester having 10 to 30 C10 in the alkyl group is preferably set to a range of 0% to 8% by weight in the graft copolymer (P). The upper limit of the content is preferably 6% by weight or less, more preferably 4% by weight or less, and even more preferably 2% by weight or less. Furthermore, the upper limit of the number of C10 in the alkyl group is not particularly limited, but may be 20 or less, 15 or less, or 12 or less.

[0031] The (meth)acrylic acid ester (a1-1) that does not have a reactive silicon group preferably contains at least an alkyl (meth)acrylic acid ester with three or fewer C1 atoms in the alkyl group. This makes it easier to construct the graft copolymer (P) to be solid at room temperature and to obtain a cured product with good mechanical properties. Particularly from the viewpoint of mechanical properties after curing, the monomer content is preferably 30% by weight or more, more preferably 35% by weight or more, and even more preferably 40% by weight or more in the graft copolymer (P).

[0032] On the other hand, the upper limit of the content of alkyl (meth)acrylate esters with three or fewer carbon atoms in the alkyl group is preferably 60% by weight or less, and more preferably 50% by weight or less, in the graft copolymer (P), from the viewpoint of lowering the viscosity of the curable composition when heated and melted.

[0033] As the alkyl (meth)acrylate ester with three or fewer carbon atoms in the alkyl group, from the viewpoint of mechanical properties after curing, alkyl methacrylate esters with three or fewer carbon atoms in the alkyl group are preferred, and methyl methacrylate is particularly preferred.

[0034] As the (meth)acrylic acid ester (a1-1) that does not have reactive silicon groups, butyl acrylate may be used or not, but its content is preferably 0% to 8% by weight in the graft copolymer (P) because it can improve the strength of the cured product. The upper limit is more preferably 6% by weight or less, even more preferably 4% by weight or less, and particularly preferably 3% by weight or less. The lower limit is preferably 0.1% by weight or more, and more preferably 0.3% by weight or more.

[0035] The (meth)acrylic acid ester (a1-2) having a reactive silicon group is any monomer and may not be used, but its use is preferred. The reactive silicon group possessed by (a1-2) is the reactive silicon group represented by the general formula (1) described above. By using monomer (a1-2), a reactive silicon group can be introduced into the side chain (non-terminal portion) of polymer block (A).

[0036] The (meth)acrylic acid esters (a1-2) having a reactive silicon group are not particularly limited, but examples include 3-(meth)acryloxypropyltrimethoxysilane, 3-(meth)acryloxypropyltriethoxysilane, 3-(meth)acryloxypropyldimethoxymethylsilane, (meth)acryloxymethyltrimethoxysilane, and (meth)acryloxymethyldimethoxymethylsilane. These compounds may be used individually or in combination of two or more.

[0037] When using a (meth)acrylic acid ester (a1-2) having a reactive silicon group, the content of (a1-2) is preferably 0.5% by weight or more and 30% by weight or less of the total amount of constituent units forming the polymer block (A), more preferably 1% by weight or more and 20% by weight or less, even more preferably 2% by weight or more and 15% by weight or less, and particularly preferably 3% by weight or more and 10% by weight or less.

[0038] From the viewpoint of mechanical properties after curing, the content of (meth)acrylic acid ester (a1) in polymer block (A) is preferably 50% by weight or more, more preferably 70% by weight or more, even more preferably 80% by weight or more, and particularly preferably 90% by weight or more, of the total amount of constituent units forming polymer block (A). The upper limit is preferably 100% by weight or less, and more preferably 95% by weight or less.

[0039] <Chain transfer agent having a mercapto group (a2)> It is preferable that the polymer block (A) contains constituent units derived from the chain transfer agent having a mercapto group (a2). By using the chain transfer agent having a mercapto group (a2), the molecular weight of the polymer block (A) can be controlled. In addition, the molecular weight distribution of the graft copolymer (P) can be made relatively narrow, and gelation during the synthesis of the graft copolymer (P) can be suppressed. Furthermore, it becomes possible to preferentially synthesize polymer molecules in which one polymer block (B) is introduced into one molecule of the graft copolymer (P).

[0040] The chain transfer agent (a2) having a mercapto group may not have a reactive silicon group, but it is preferable that it has a reactive silicon group. The reactive silicon group is the reactive silicon group represented by the general formula (1) described above. By having a reactive silicon group in the chain transfer agent (a2) having a mercapto group, a reactive silicon group can be introduced to the molecular chain ends of the polymer block (A).

[0041] The chain transfer agent (a2) having a mercapto group is not particularly limited, but examples include 3-mercaptopropyldimethoxymethylsilane, 3-mercaptopropyltrimethoxysilane, (mercaptomethyl)dimethoxymethylsilane, (mercaptomethyl)trimethoxysilane, n-dodecylmercaptan, tert-dodecylmercaptan, laurylmercaptan, and the like.

[0042] The content of the chain transfer agent (a2) having a mercapto group is preferably 1% by weight or more and 10% by weight or less of the total amount of constituent units forming the polymer block (A), more preferably 2% by weight or more and 8% by weight or less, and even more preferably 3% by weight or more and 7% by weight or less.

[0043] Furthermore, the content of the chain transfer agent (a2) having a mercapto group is preferably 0.1 mol% to 10 mol%, more preferably 0.4 mol% to 9 mol%, even more preferably 0.5 mol% to 7 mol%, and particularly preferably 0.6 mol% to 6 mol% of the total amount of constituent units forming the polymer block (A).

[0044] The ratio of polymer block (B) content to chain transfer agent (a2) content having mercapto groups is preferably 0.10 or higher, more preferably 0.15 or higher, even more preferably 0.20 or higher, even more preferably 0.25 or higher, and particularly preferably 0.30 or higher, as this improves initial fixation. The upper limit of the above molar ratio is preferably 0.40 or lower, and more preferably 0.35 or lower, as this reduces viscosity during heating and melting.

[0045] When polymer block (A) is formed using a chain transfer agent (a2) having a mercapto group, polymer block (A) has substituents (described later -S-R) derived from the chain transfer agent (a2) having a mercapto group. ８ It has a structure represented by . Therefore, the polymer block (A) or graft copolymer (P) may contain sulfur atoms.

[0046] The sulfur atom concentration derived from the chain transfer agent (a2) is preferably 4,000 ppm or more and 9,000 ppm or less in the graft copolymer (P). This sulfur atom concentration is a value relative to the solid content of the graft copolymer (P), and the solvent is excluded from its calculation.

[0047] The sulfur atom concentration is a value that reflects the proportion of chain transfer agent used in the graft copolymer (P). When the sulfur atom concentration is 4,000 ppm or higher, excessive high molecular weight formation of the polymer block (A) is suppressed, and as a result, the viscosity of the curable composition when heated and melted can be made lower. Furthermore, the mechanical properties after curing can be made better. On the other hand, when the sulfur atom concentration is 9,000 ppm or lower, excessive low molecular weight formation of the polymer block (A) is suppressed, and the initial strength of the cured product can be made good.

[0048] The lower limit of the sulfur atom concentration is preferably 4,500 ppm or more, more preferably 5,000 ppm or more. The upper limit is preferably 8,000 ppm or less, even more preferably 7,000 ppm or less, and particularly preferably 6,500 ppm or less.

[0049] The method for measuring the sulfur atom concentration is not particularly limited. It can be measured by known elemental analysis methods such as organic elemental analysis and X-ray fluorescence analysis. Alternatively, the sulfur atom concentration may be a theoretical value calculated from the total amount of components used in the production of the graft copolymer (P) and the amount of the chain transfer agent (a2) having a mercapto group.

[0050] <Other monomers (a3)> The components forming the polymer block (A) may or may not contain other monomers (a3) ​​that do not fall under either (a1) or (a2) as described above.

[0051] Other monomers (a3) ​​include, for example, styrene 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 monoalkyl esters and fumarate dialkyl esters; maleimide, methyl maleimide, ethyl maleimide, propyl maleimide, and butyl maleimide. Examples include maleimide monomers such as hexylmaleimide, 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. Other monomers may be used individually or in combination of two or more.

[0052] Polymer block (A) may have reactive silicon groups by satisfying either or both of the following two conditions: Condition 1: (meth)acrylic acid ester (a1) contains (meth)acrylic acid ester (a1-2) having reactive silicon groups. Condition 2: The chain transfer agent (a2) having mercapto groups further has reactive silicon groups.

[0053] To obtain a cured product with high strength, it is preferable to introduce reactive silicon groups by both conditions 1 and 2. Specifically, the reactive silicon group equivalent from (a1) is preferably 0.01 mmol / g or more, and more preferably 0.10 mmol / g or more, from the viewpoint of the resilience of the cured product. Furthermore, the reactive silicon group equivalent from (a1) is preferably 0.40 mmol / g or less, more preferably 0.30 mmol / g or less, and even more preferably 0.15 mmol / g or less, from the viewpoint of the elongation of the cured product.

[0054] On the other hand, the reactive silicon group equivalent derived from (a2) is preferably 0.05 mmol / g or more, and more preferably 0.10 mmol / g or more. Furthermore, the reactive silicon group equivalent derived from (a2) is preferably 0.40 mmol / g or less, more preferably 0.30 mmol / g or less, and even more preferably 0.20 mmol / g or less.

[0055] The reactive silicon group equivalent derived from (a1) or (a2) can be calculated in accordance with the method for calculating the reactive silicon group equivalent of the graft copolymer (P) described above.

[0056] <Polyoxyalkylene Polymer Block (B)> The polyoxyalkylene polymer constituting the polyoxyalkylene polymer block (B) is not particularly limited, and examples include polyoxyethylene, polyoxypropylene, polyoxybutylene, polyoxytetramethylene, polyoxyethylene-polyoxypropylene copolymer, and polyoxypropylene-polyoxybutylene copolymer. Among these, polyoxypropylene is preferred.

[0057] The main chain skeleton of the polyoxyalkylene polymer may be linear or branched, but it is preferable that it be linear.

[0058] The number-average molecular weight of the polyoxyalkylene polymer block (B) is 1,000 or more. Within this range, the cured product obtained by curing the curable composition according to this disclosure can exhibit high strength and high elongation properties. The number-average molecular weight is preferably 5,000 or more, more preferably 10,000 or more, and even more preferably 15,000 or more. The upper limit is preferably 100,000 or less, more preferably 50,000 or less, even more preferably 30,000 or less, even more preferably 26,000 or less, and particularly preferably 23,000 or less, from the viewpoint of viscosity when heated and melted.

[0059] The molecular weight distribution (weight-average molecular weight (Mw) / number-average molecular weight (Mn)) of the polyoxyalkylene polymer block (B) is not particularly limited, but is preferably narrow, specifically less than 2.0, more preferably 1.6 or less, even more preferably 1.4 or less, even more preferably 1.3 or less, particularly preferably 1.2 or less, and most preferably 1.1 or less. The narrower the molecular weight distribution, the lower the viscosity tends to be when heated and melted.

[0060] The number-average molecular weight (Mn) and weight-average molecular weight (Mw) of polymer block (B) are values ​​measured in polystyrene equivalent by gel permeation chromatography (GPC) for the polyfunctional macromonomer (a4) described later. The detailed measurement method is described in the examples.

[0061] <Polyfunctional Macromonomer (a4)> The polyoxyalkylene polymer block (B) can be introduced into the graft copolymer (P) by using a polyoxyalkylene polymer (a4) that has an average of more than one (meth)acryloyl group in its molecule. Polymer (a4) is a polymer itself, but it is one of the components that make up the graft copolymer (P). Because polymer (a4) has (meth)acryloyl groups, it can copolymerize with (meth)acrylic acid ester (a1). Moreover, since polymer (a4) has more than one (meth)acryloyl group in one molecule, it can function as a so-called polyfunctional macromonomer. Hereinafter, polymer (a4) will also be called polyfunctional macromonomer (a4).

[0062] The (meth)acryloyl group of the polyfunctional macromonomer (a4) is not particularly limited, but can be represented by the following general formula (2) or (3): CH ２ = C(R ２ )-C(=O)-OR ３ -NH-C(=O)-OB (2) CH ２ = C(R ２ )-C(=O)-O-B (3) In each formula, R ２ represents a hydrogen or methyl group. B represents the main chain skeleton of the polyfunctional macromonomer (a4), i.e., the main chain skeleton of the polyoxyalkylene polymer.

[0063] R in equation (2) ３ This represents a divalent saturated or unsaturated hydrocarbon group having 1 to 20 carbon atoms. The number of carbon atoms is preferably 1 to 10, more preferably 1 to 6, and particularly preferably 1 to 3.

[0064] The polyfunctional macromonomer (a4) has an average of more than one (meth)acryloyl group per molecule. From the viewpoint of improving the strength of the cured product, the average number of (meth)acryloyl groups per molecule of the polyfunctional macromonomer (a4) is 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. This average number is, for example, １ It can be calculated from the 1H NMR spectrum.

[0065] Furthermore, the polyfunctional macromonomer (a4) may have only an acryloyl group as the (meth)acryloyl group, or only a methacryloyl group, or it may have both an acryloyl group and a methacryloyl group.

[0066] The polyfunctional macromonomer (a4) may have (meth)acryloyl groups at either the molecular chain ends or side chains, or both, of the polyoxyalkylene polymer. From the viewpoint of excellent mechanical properties, it is preferable that the groups be at the molecular chain ends. In particular, it is especially preferable that the polyfunctional macromonomer (a4) has a linear main chain skeleton and has (meth)acryloyl groups at both ends of its molecular chain.

[0067] There are no particular limitations on the method for synthesizing the polyfunctional macromonomer (a4), but for example, one method involves preparing a polyoxyalkylene polymer having one or more hydroxyl groups in the molecule (preferably a linear polyoxyalkylene polymer having hydroxyl groups at both ends), and then introducing (meth)acryloyl groups using these hydroxyl groups.

[0068] As an example of a method for synthesizing polyfunctional macromonomers (a4), a compound having an isocyanate group and a (meth)acryloyl group can be reacted with a polyoxyalkylene polymer having a hydroxyl group to form a urethane bond and introduce a (meth)acryloyl group. Specific examples of the compound having an isocyanate group and a (meth)acryloyl group include, for example, isocyanate ethyl (meth)acrylate, isocyanate propyl (meth)acrylate, isocyanate butyl (meth)acrylate, and isocyanate hexyl (meth)acrylate.

[0069] Another example of a method for synthesizing polyfunctional macromonomers (a4) is to introduce isocyanate groups into a polyoxyalkylene polymer having hydroxyl groups by reacting a diisocyanate compound with the polymer, and then introduce (meth)acryloyl groups by reacting a compound having both hydroxyl groups and (meth)acryloyl groups. Specific examples of the diisocyanate compounds include, for example, tolylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, and 4,4'-diphenylmethane diisocyanate. Specific examples of compounds having both hydroxyl groups and (meth)acryloyl groups include, for example, hydroxybutyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxyethyl (meth)acrylate, polyethylene glycol mono(meth)acrylate, and polypropylene glycol mono(meth)acrylate.

[0070] As yet another example of a method for synthesizing polyfunctional macromonomers (a4), a carboxyl group can be introduced into a polyoxyalkylene polymer having a hydroxyl group by reacting an acid anhydride with the polymer, and then a (meth)acryloyl group can be introduced by reacting the polymer with a compound having an epoxy group and a (meth)acryloyl group. Specific examples of the acid anhydrides include succinic anhydride, maleic anhydride, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, methylhymic anhydride, trimellitic anhydride, methylnadic anhydride, and dodecyl succinic anhydride. Specific examples of the compounds having an epoxy group and a (meth)acryloyl group include glycidyl (meth)acrylate.

[0071] Another example of a method for synthesizing polyfunctional macromonomers (a4) is to dehydrate and condense methacrylic acid and acrylic acid with a polyoxyalkylene polymer containing hydroxyl groups. Furthermore, to carry out the reaction under milder conditions, one can react a polyoxyalkylene polymer containing hydroxyl groups with methacrylate chloride, methacrylate bromide, methacrylate iodide, acrylate chloride, acrylate bromide, or acrylate iodide.

[0072] In the graft copolymer (P), the ratio of polymer block (A) to polymer block (B) can be appropriately set according to the effect to be achieved. Specifically, it is preferable that the ratio of polymer block (A) to the total of polymer block (A) and polymer block (B) is 35 to 70% by weight, and the ratio of polymer block (B) is 30 to 65% by weight. If the ratio of polymer block (B) is 30% by weight or more, the elongation of the cured product can be increased. On the other hand, if the ratio of polymer block (A) is 35% by weight or more, the compatibility with reactive silicon group-containing (meth)acrylic acid ester polymer (Q) can be increased, the melt viscosity of the curable composition can be reduced, and the strength of the cured product can be increased.

[0073] The proportion of polymer block (A) is preferably 40 to 65% by weight, and the proportion of polymer block (B) is preferably 35 to 60% by weight, with the former being more preferably 45 to 60% by weight and the latter 40 to 55% by weight.

[0074] Furthermore, from the viewpoint of the effects described above, the content of polymer blocks (B) is preferably 0.05 mol% to 6.0 mol%, more preferably 0.1 mol% to 2.3 mol%, and even more preferably 0.2 mol% to 1.5 mol%, of the total amount of constituent units forming the graft copolymer (P).

[0075] The average number of polymer blocks (B) per molecule of graft copolymer (P) is preferably 0.05 or more and 2.0 or less, from the viewpoint of the strength of the resulting cured product. The lower limit is more preferably 0.07 or more, and even more preferably 0.08 or more. The upper limit is more preferably 1.5 or less, and even more preferably 1.0 or less. The average number can be calculated using the following formula: Formula: Number-average molecular weight of graft copolymer (P) (g / mol) / (Weight of graft copolymer (P) (g) / (Number of moles of polymer blocks (B)))

[0076] <Block Bonding Configuration> In the graft copolymer (P), the (meth)acrylic acid ester polymer block (A) and the polyoxyalkylene polymer block (B) are bonded in the order A-B-A. However, the graft copolymer (P) is not limited to only the A-B-A triblock, but may also further include a multiblock in which block (B) and / or block (A) are further bonded to the triblock, or an A-B diblock.

[0077] Graft copolymers (P) can be prepared by free radical polymerization. When prepared by free radical polymerization, some molecules in the graft copolymer (P) may include polymer components in which block (A) and block (B) are not bonded to each other. In this disclosure, graft copolymer (P) is defined as containing such unbonded polymer components and graft copolymer components other than the A-B-A triblock described above. The ratio of graft copolymer components in which block (A) and block (B) are bonded to unbonded polymer components can be determined by known means, such as GPC analysis.

[0078] In the graft copolymer (P), it is preferable that polymer block (A) and polymer block (B) are linked via ester bonds derived from the (meth)acryloyl group in the polyfunctional macromonomer (a4) (i.e., ester bonds in the general formula (2) or (3)).

[0079] The bonding configuration between polymer block (A) and polymer block (B) is not particularly limited, but can be represented by the following general formula (4) or (5): A-C(=O)-O-R ３ -NH-C(=O)-O-B (4) A-C(=O)-O-B (5) In each formula, A represents polymer block (A) and B represents polymer block (B). R ３ This is the same as what was described above for equation (2).

[0080] It is preferable that the (meth)acrylic acid ester polymer block (A) is composed of a hard polymer and the polyoxyalkylene polymer block (B) is composed of a soft polymer, as this makes it easier to obtain a cured product with high strength and high elongation. Here, a hard polymer refers to a polymer with a high glass transition temperature. A soft polymer refers to a polymer with a low glass transition temperature.

[0081] When the (meth)acrylic acid ester polymer block (A) is composed of a hard polymer, i.e., a polymer with a high glass transition temperature, it is preferable that the (meth)acrylic acid ester (a1) of polymer block (A) contains an alkyl methacrylate ester with three or fewer C1 atoms in the alkyl group.

[0082] When a polymer block (A) is formed using a chain transfer agent (a2) having a mercapto group, the substituents originating from (a2) are -S-R ８ It may have a structure represented by the above formula. In the above formula, S represents a sulfur atom, and R ８ R represents a hydrocarbon group which may have a reactive silicon group. Examples of the hydrocarbon group include alkyl groups, aryl groups, or aralkyl groups having 1 to 20 carbon atoms. The reactive silicon group is the reactive silicon group represented by the general formula (1) described above. ８ Specific examples include, for instance, reactive silicon-containing methyl groups, reactive silicon-containing propyl groups, n-dodecyl groups, tert-dodecyl groups, and lauryl groups.

[0083] The graft copolymer (P) may have a linear structure in which the ends of polymer block (A) and polymer block (B) are connected, but it is preferable that it includes an H-type structure. Figure 1 shows a conceptual diagram of the H-type structure. In this structure, the two vertical bars represent polymer block (A), and the one horizontal bar represents polymer block (B). Both ends of polymer block (B) are bonded to the non-terminal portions of polymer block (A). At one end of each of the two polymer blocks (A), there is a substituent derived from a chain transfer agent having a mercapto group and a reactive silicon group, namely -S-R ８ -SiR １ ３－ａ X ａ It is bonded. Also, -SiR is present in the non-terminal portion of polymer block (A). １ ３－ａ X ａ These are randomly bonded, which originate from (meth)acrylic acid esters (a1-2) having reactive silicon groups.

[0084] The H-type structure can be formed by random polymerization of a polyfunctional macromonomer (a4), which has (meth)acryloyl groups at both ends of a polyoxyalkylene polymer molecular chain, with a (meth)acrylic acid ester (a1) and a chain transfer agent (a2) having a mercapto group.

[0085] <Molecular Weight of Graft Copolymer (P)> The number average molecular weight of the graft copolymer (P) is not particularly limited, but is preferably 500 to 50,000 in polystyrene equivalent molecular weight as measured by GPC, more preferably 500 to 30,000, and particularly preferably 1,000 to 10,000. In particular, since a low viscosity graft copolymer can be obtained, the number average molecular weight of the graft copolymer (P) is preferably 7,000 or less, more preferably 5,000 or less, and even more preferably 4,000 or less.

[0086] The weight-average molecular weight of the graft copolymer (P) is not particularly limited, but is preferably 500 to 80,000 in polystyrene equivalent molecular weight as measured by GPC, more preferably 3,000 to 70,000, and particularly preferably 5,000 to 65,000. In particular, the weight-average molecular weight of the graft copolymer (P) is preferably 40,000 or less, as this yields a cured product with low viscosity and high strength.

[0087] The molecular weight distribution (weight-average molecular weight (Mw) / number-average molecular weight (Mn)) of the graft copolymer (P) is not particularly limited, but from the viewpoint of making the graft copolymer low viscosity, it is preferably 3.0 to 11.0 and more preferably 5.0 to 10.0.

[0088] The number-average molecular weight (Mn) and weight-average molecular weight (Mw) of the graft copolymer (P) are measured in polystyrene equivalents by gel permeation chromatography (GPC). The detailed measurement method is described in the examples. As mentioned above, the graft copolymer (P) may contain polymer components in which block (A) and block (B) are not bonded to each other, but the number-average molecular weight, weight-average molecular weight, and molecular weight distribution of the graft copolymer (P) are values ​​measured for the entire graft copolymer (P), including such polymer components.

[0089] <Method for Producing Graft Copolymer (P)> Graft copolymer (P) can be produced by polymerizing a (meth)acrylic acid ester (a1), a chain transfer agent having any mercapto group (a2), any other monomer (a3), and a polyfunctional macromonomer (a4). The polymerization method is not particularly limited, but may be a general free radical polymerization. According to this disclosure, even though it is free radical polymerization, polymerization can be controlled, graft copolymer (P) can be produced, and its molecular weight distribution can be made relatively narrow.

[0090] Examples of polymerization initiators usable in the aforementioned 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-carbonitride). Diacyl peroxides such as benzoyl peroxide, isobutyryl peroxide, isononanoyl peroxide, decanoyl peroxide, lauroyl peroxide, parachlorobenzoyl peroxide, and di(3,5,5-trimethylhexanoyl) peroxide; diisopropyl peroxide, di-sec-butyl peroxide, di-2-ethylhexyl peroxide, di-1-methylheptyl peroxide, and di-3-methoxybutyl peroxide; Peroxy dicarbonates such as dichlorohexyl per dicarbonate; peroxyesters such as tert-butyl perbenzoate, tert-butyl peracetate, tert-butyl per-2-ethylhexanoate, tert-butyl perisobutyrate, tert-butyl perpivalate, tert-butyl diperadipate, and quyl perneodecanoate; ketone peroxides such as methyl ethyl ketone peroxide and cyclohexanone peroxide. Examples of polymerization initiators include dialkyl peroxides such as di-tert-butyl peroxide, diqumyl peroxide, tert-butylqumyl 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 individually or in combination of two or more.

[0091] Examples of solvents usable 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 ethyl acetate, butyl acetate, isobutyl 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. Since the resulting graft copolymer tends to be poorly soluble in alcohol-based solvents, it is preferable to use non-alcohol-based solvents. In particular, it is preferable to use carboxylic acid ester-based solvents. Aromatic solvents are preferred due to their high solubility.

[0092] As described above, the graft copolymer (P) can be made to have reactive silicon groups by using (meth)acrylic acid esters (a1-2) having reactive silicon groups, or by using a chain transfer agent (a2) having reactive silicon groups in addition to mercapto groups. Both methods may be used in combination. By using (meth)acrylic acid esters (a1-2) having reactive silicon groups, reactive silicon groups can be randomly introduced into the side chains of polymer block (A). Alternatively, by using a chain transfer agent (a2) having reactive silicon groups in addition to mercapto groups, reactive silicon groups can be introduced into the terminals of polymer block (A).

[0093] However, the following methods can also be used in combination to further introduce reactive silicon groups into the graft copolymer (P): (i) A monomer having a reactive functional group (V group) copolymerizes with a (meth)acrylic acid ester (a1), and then reacts the resulting copolymer with a compound having a functional group that reacts with the V group and a reactive silicon group. Specifically, examples include copolymerizing 2-hydroxyethyl acrylate and then reacting it with an isocyanate silane compound having a reactive silicon group, or copolymerizing glycidyl acrylate and then reacting it with an aminosilane compound having a reactive silicon group. (ii) A method of introducing reactive silicon groups by modifying the terminal functional groups of a (meth)acrylic acid ester copolymer synthesized by living radical polymerization. (meth)acrylic acid ester copolymers obtained by living radical polymerization readily accept the introduction of functional groups at the polymer ends, and reactive silicon groups can be introduced at the polymer ends by modifying them.

[0094] Examples of compounds having a functional group that reacts with the V group and a reactive silicon group used in method (i) include isocyanate silane compounds such as 3-isocyanate propyl dimethoxymethylsilane, 3-isocyanate propyl trimethoxysilane, 3-isocyanate propyl triethoxysilane, isocyanate methyl dimethoxymethylsilane, isocyanate methyl trimethoxysilane, and isocyanate methyl triethoxysilane; 3-glycidoxypropyl dimethoxymethylsilane, 3-glycidoxypropyl trimethoxysilane, 3-glycidoxypropyl triethoxysilane, and glycidoxymethyl Examples include epoxysilane compounds such as dimethoxymethylsilane, glycidoxymethyltrimethoxysilane, and glycidoxymethyltriethoxysilane; and aminosilane compounds such as 3-aminopropyldimethoxymethylsilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, aminomethyldimethoxymethylsilane, aminomethyltrimethoxysilane, aminomethyltriethoxysilane, N-cyclohexylaminomethyldimethoxymethylsilane, N-cyclohexylaminomethyltrimethoxysilane, and N-cyclohexylaminomethyltriethoxysilane.

[0095] Method (ii) can utilize any modification reaction, but examples include a method using a compound having a reactive group and a reactive silicon group that can react with terminal functional groups obtained by living radical polymerization, or a method in which a double bond is introduced to the polymer terminal using a compound having a reactive group and a double bond that can react with terminal functional groups, and then a reactive silicon group is introduced using a hydrosilylation reaction or the like.

[0096] <Reactive silicon group-containing (meth)acrylic acid ester polymer (Q)> The curable composition according to this disclosure further contains a (meth)acrylic acid ester polymer (Q) having a reactive silicon group. By incorporating polymer (Q), the viscosity of the curable composition during heating and melting can be reduced while maintaining the elongation after curing.

[0097] The reactive silicon group of the (meth)acrylic acid ester polymer (Q) is represented by the general formula (1) described above, and may be the same as or different from the reactive silicon of the graft copolymer (P).

[0098] In the reactive silicon group of the (meth)acrylic acid ester polymer (Q), a in formula (1) represents either 2 or 3, but it is preferable that a is 2 because it improves the elongation after curing. In particular, it is preferable that the reactive silicon group of polymer (Q) is a dimethoxymethylsilyl group.

[0099] The reactive silicon group equivalent of the (meth)acrylic acid ester polymer (Q) is not particularly limited, but from the viewpoint of improving the strength of the cured product, it 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, from the viewpoint of suppressing a decrease in the elongation of the cured product. Furthermore, in order to obtain a cured product with high rigidity, the reactive silicon group equivalent is particularly preferably 0.6 mmol / g or more and 1.0 mmol / g or less.

[0100] The (meth)acrylic acid ester monomers constituting the main chain of the (meth)acrylic acid ester polymer (Q) are not particularly limited, and various types can be used. Specifically, methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, n-pentyl (meth)acrylate, n-hexyl (meth)acrylate, cyclohexyl (meth)acrylate, n-heptyl (meth)acrylate, n-octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, and (meth)acrylate Nyl, Decyl (meth)acrylate, Dodecyl (meth)acrylate, Phenylen (meth)acrylate, Toluyl (meth)acrylate, Benzyl (meth)acrylate, 2-Methoxyethyl (meth)acrylate, 3-Methoxybutyl (meth)acrylate, 2-Hydroxyethyl (meth)acrylate, 2-Hydroxypropyl (meth)acrylate, Stearyl (meth)acrylate, Glycidyl (meth)acrylate, (3-Trimethoxysilyl)propyl (meth)acrylate, (3-Dimethyl Examples of (meth)acrylic acid monomers include toxymethylsilyl)propyl, (2-trimethoxysilyl)ethyl (meth)acrylate, (2-dimethoxymethylsilyl)ethyl (meth)acrylate, trimethoxysilylmethyl (meth)acrylate, (dimethoxymethylsilyl)methyl (meth)acrylate, ethylene oxide adducts of (meth)acrylic acid, trifluoromethylmethyl (meth)acrylate, 2-trifluoromethylethyl (meth)acrylate, 2-perfluoroethylethyl (meth)acrylate, 2-perfluoroethyl-2-perfluorobutylethyl (meth)acrylate, perfluoroethyl (meth)acrylate, trifluoromethyl (meth)acrylate, bis(trifluoromethyl)methyl (meth)acrylate, 2-trifluoromethyl-2-perfluoroethylethyl (meth)acrylate, 2-perfluorohexylethyl (meth)acrylate, 2-perfluorodecylethyl (meth)acrylate, and 2-perfluorohexadecylethyl (meth)acrylate.

[0101] Other monomer units include, for example, acrylic acids such as acrylic acid and methacrylic acid; monomers containing an amide group, such as N-methylolacrylamide and N-methylolmethacrylamide; monomers containing an epoxy group, such as glycidyl acrylate and glycidyl methacrylate; and monomers containing a nitrogen group, such as diethylaminoethyl acrylate and diethylaminoethyl methacrylate.

[0102] The (meth)acrylic acid ester polymer (Q) may also be a polymer obtained by copolymerizing a (meth)acrylic acid ester monomer with a vinyl monomer copolymerizable therewith. Such vinyl monomers are not particularly limited and include, for example, styrene monomers such as styrene, vinyltoluene, α-methylstyrene, chlorostyrene, styrenesulfonic acid and its salts; fluorine-containing vinyl monomers such as perfluoroethylene, perfluoropropylene, and vinylidene fluoride; silicon-containing vinyl monomers such as vinyltrimethoxysilane and vinyltriethoxysilane; maleic anhydride, maleic acid, monoalkyl and dialkyl esters of maleic acid; fumaric acid, monoalkyl and dialkyl esters of fumaric acid; maleimide, methylmaleimide, ethylmaleimide, propylmaleimide, butylmaleimide, hexylmaleimide, and Examples include maleimide monomers such as cutylmaleimide, dodecylmaleimide, stearylmaleimide, phenylmaleimide, and cyclohexylmaleimide; nitrile group-containing vinyl monomers such as acrylonitrile and methacrylonitrile; amide group-containing vinyl monomers such as acrylamide and methacrylamide; vinyl ester monomers such as vinyl acetate, vinyl propionate, vinyl pivalate, vinyl benzoate, and vinyl cinnamate; alkenyl monomers such as ethylene and propylene; conjugated diene monomers such as butadiene and isoprene; and vinyl chloride, vinylidene chloride, allyl chloride, and allyl alcohol. Multiple of these can also be used as copolymerization components.

[0103] As the (meth)acrylic acid ester polymer (Q), a copolymer consisting of a styrene monomer and a (meth)acrylic acid monomer is preferred due to its excellent physical properties, and a (meth)acrylic acid ester polymer consisting of an acrylic acid ester monomer and a methacrylic acid ester monomer is more preferred. Unlike the graft copolymer (P), the (meth)acrylic acid ester polymer (Q) preferably does not contain a polyoxyalkylene polymer backbone.

[0104] The method for introducing reactive silicon groups into (meth)acrylic acid ester polymers is not particularly limited, and for example, the following methods can be used: (iv) A method of copolymerizing a compound having a polymerizable unsaturated group and a reactive silicon-containing group together with the above-mentioned monomer. When this method is used, the reactive silicon groups tend to be introduced randomly into the main chain of the polymer. (v) A method of polymerizing (meth)acrylic acid ester polymers using a mercaptosilane compound having a reactive silicon-containing group as a chain transfer agent. When this method is used, the reactive silicon groups can be introduced to the ends of the polymer. (vi) A method of copolymerizing a compound having a polymerizable unsaturated group and a reactive functional group (V group), and then reacting it with a compound having a reactive silicon group and a functional group that reacts with the V group. Specifically, examples include a method of copolymerizing 2-hydroxyethyl acrylate and then reacting it with an isocyanate silane having a reactive silicon-containing group, or a method of copolymerizing glycidyl acrylate and then reacting it with an aminosilane compound having a reactive silicon-containing group. (vii) A method for introducing reactive silicon groups by modifying the terminal functional groups of (meth)acrylic acid ester polymers synthesized by living radical polymerization. (meth)acrylic acid ester polymers obtained by living radical polymerization readily accept the introduction of functional groups at the polymer ends, and reactive silicon groups can be introduced at the polymer ends by modifying them.

[0105] Examples of silicon compounds that can be used to introduce reactive silicon groups into a (meth)acrylic acid ester polymer (Q) using the above method include the following compounds. Examples of compounds having a polymerizable unsaturated group and a reactive silicon group used in method (iv) include (meth)acrylic acid 3-(trimethoxysilyl)propyl, (meth)acrylic acid 3-(triethoxysilyl)propyl, (meth)acrylic acid (trimethoxysilyl)methyl, and (meth)acrylic acid (triethoxysilyl)methyl. (meth)acrylic acid 3-(trimethoxysilyl)propyl is particularly preferred.

[0106] Examples of mercaptosilane compounds having a reactive silicon-containing group used in method (v) include 3-mercaptopropyltrimethoxysilane and (mercaptomethyl)trimethoxysilane.

[0107] Examples of compounds having a functional group that reacts with the reactive silicon group and the V group used in method (vi) include isocyanate silane compounds such as 3-isocyanatetopropyltrimethoxysilane, 3-isocyanatetopropyltriethoxysilane, isocyanatemethyltrimethoxysilane, and isocyanatemethyltriethoxysilane; epoxy silane compounds such as 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, glycidoxymethyltrimethoxysilane, and glycidoxymethyltriethoxysilane; and aminosilane compounds such as 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, aminomethyltrimethoxysilane, aminomethyltriethoxysilane, N-cyclohexylaminomethyltrimethoxysilane, and N-cyclohexylaminomethyltriethoxysilane.

[0108] In the method described in (vii) above, any modification reaction can be used. For example, a method can be used in which a compound having a functional group and a silicon group that can react with the terminal reactive group obtained by polymerization is used, or a method can be used in which a double bond is introduced to the polymer terminal using a compound having a functional group and a double bond that can react with the terminal reactive group, and a reactive silicon group is introduced to this by hydrosilylation or the like.

[0109] These methods may be used in any combination. For example, combining method (vi) and method (v) can yield a (meth)acrylic acid ester polymer (Q) having reactive silicon groups at both the molecular chain ends and / or side chains.

[0110] The (meth)acrylic acid ester polymer (Q) is preferable if it contains a polymer that contains 40% by weight or more of alkyl (meth)acrylate, in which the alkyl group has 1 to 3 carbon atoms, in the total monomer, because the cured product can have high rigidity. The (meth)acrylic acid ester polymer (Q) may consist only of a polymer that contains 40% by weight or more of alkyl (meth)acrylate, in which the alkyl group has 1 to 3 carbon atoms, in the total monomer, but it is preferable if it also contains a polymer that contains 40% by weight or more of alkyl (meth)acrylate, in which the alkyl group has 4 to 30 carbon atoms, in the total monomer, and is a mixture of both, because rigidity, elongation, and strength are improved.

[0111] Furthermore, it is preferable that the (meth)acrylic acid ester polymer (Q) contains a copolymer containing 40% by weight or more of alkyl (meth)acrylate having 1 to 3 C1 of the alkyl group and 40% by weight or more of alkyl (meth)acrylate having 4 to 30 C1 of the alkyl group, as this improves rigidity, elongation, and strength.

[0112] The monomer composition of the (meth)acrylic acid ester polymer (Q) can be selected according to the application and purpose. For applications requiring strength, a relatively high glass transition temperature (Tg) is preferred, preferably between 0°C and 200°C, and more preferably between 20°C and 100°C. The Tg can be determined using the following Fox formula.

[0113] Fox's formula: 1 / (Tg(K)) = Σ(Mi / Tgi) (wherein Mi is the weight fraction of monomer i constituting the polymer, and Tgi is the glass transition temperature (K) of the homopolymer of monomer i).

[0114] The number-average molecular weight of the (meth)acrylic acid ester polymer (Q) is not particularly limited, but is preferably 500 to 20,000, more preferably 500 to 10,000, even more preferably 1,000 to 7,000, and particularly preferably 1,000 to 4,500, based on polystyrene-equivalent molecular weight measured by GPC.

[0115] In the curable composition according to this disclosure, the amount of reactive silicon group-containing (meth)acrylic acid ester polymer (Q) is 5 to 65 parts by weight per 100 parts by weight of graft copolymer (P). When the amount is 5 parts by weight or more, it is easy to achieve the effect of reducing the melt viscosity of the curable composition by the addition of polymer (Q). Preferably, it is 10 parts by weight or more, more preferably 15 parts by weight or more. It may also be 20 parts by weight or more, 30 parts by weight or more, 40 parts by weight or more, or 50 parts by weight or more. Furthermore, when the content is 65 parts by weight or less, good mechanical properties after curing can be obtained. Preferably, it is 60 parts by weight or less.

[0116] <Reactive Silicon Group-Containing Polyoxyalkylene Polymer (R)> In addition to the graft copolymer (P) and the reactive silicon group-containing (meth)acrylic acid ester polymer (Q), the curable composition according to this disclosure may further contain a polyoxyalkylene polymer (R) having a reactive silicon group. This can further reduce the melt viscosity of the curable composition and increase its strength after curing.

[0117] The reactive silicon group of the polyoxyalkylene polymer (R) is represented by the general formula (1) described above, and may be the same as or different from the reactive silicon of the graft copolymer (P) or the (meth)acrylic acid ester polymer (Q).

[0118] In the reactive silicon group of the polyoxyalkylene polymer (R), a in formula (1) represents either 2 or 3, but a is preferably 3 because it results in better strength after curing. In particular, the reactive silicon group of the polymer (R) is preferably a trimethoxysilyl group or a triethoxysilyl group, with the trimethoxysilyl group being the most preferred.

[0119] The polyoxyalkylene polymer (R) may have reactive silicon groups in locations other than the terminals, but it is preferable to have reactive silicon groups only at the terminals, as this makes it easier to obtain a rubbery cured product with high elongation and low elastic modulus.

[0120] The number of reactive silicon groups in one molecule of the organic polymer (R) is preferably 1 to 7 on average, more preferably 1 to 3.4, and particularly preferably 1 to 2.6.

[0121] Examples of the main chain skeleton of the polyoxyalkylene polymer (R) include polyoxyethylene, polyoxypropylene, polyoxybutylene, polyoxytetramethylene, polyoxyethylene-polyoxypropylene copolymer, and polyoxypropylene-polyoxybutylene copolymer. Among these, polyoxypropylene is preferred. Unlike graft copolymers (P), the polyoxyalkylene polymer (R) preferably does not contain a (meth)acrylic acid ester polymer skeleton.

[0122] The number-average molecular weight of the polyoxyalkylene polymer (R) is preferably 3,000 or more, more preferably 10,000 or more, more preferably 15,000 or more, even more preferably 20,000 or more, and particularly preferably 25,000 or more, in terms of polystyrene-equivalent molecular weight in GPC, from the viewpoint of the cured product exhibiting good mechanical properties. The upper limit is preferably 100,000 or less, more preferably 50,000 or less, even more preferably 45,000 or less, and particularly preferably 40,000 or less.

[0123] The molecular weight distribution (Mw / Mn) of the polyoxyalkylene polymer (R) 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. Furthermore, from the viewpoint of improving various mechanical properties such as the durability and elongation of the cured product, 1.2 or less is preferred. The molecular weight distribution of the polyoxyalkylene polymer (R) can be determined from the number-average molecular weight and weight-average molecular weight obtained by GPC measurement.

[0124] The main chain structure of the polyoxyalkylene polymer (R) may be linear or branched, but a linear structure is preferable to obtain a cured product with high elongation.

[0125] Polyoxyalkylene polymers are preferably obtained by a ring-opening polymerization reaction of a cyclic ether compound using a polymerization catalyst in the presence of an initiator.

[0126] Examples of cyclic ether compounds include ethylene oxide, propylene oxide, butylene oxide, tetramethylene oxide, and tetrahydrofuran. These cyclic ether compounds may be used individually or in combination of two or more. Among the cyclic ether compounds, propylene oxide is particularly preferred because it yields amorphous and relatively low-viscosity polyoxyalkylene polymers.

[0127] Examples of initiators include alcohols such as butanol, ethylene glycol, propylene glycol, propylene glycol monoalkyl ether, butanediol, hexamethylene glycol, neopentyl glycol, diethylene glycol, dipropylene glycol, triethylene glycol, glycerin, trimethylolmethane, trimethylolpropane, pentaerythritol, and sorbitol; and hydroxyl-terminated polyoxyalkylene polymers with a number average molecular weight of 300 to 4,000, such as polyoxypropylenediol, polyoxypropylenetriol, polyoxyethylenediol, and polyoxyethylenetriol.

[0128] Examples of synthesis methods for polyoxyalkylene polymers include, but are not limited to, polymerization methods using alkaline catalysts such as KOH, polymerization methods using transition metal compound-porphyrin complex catalysts such as the complex obtained by reacting an organoaluminum compound with porphyrin as shown in Japanese Patent Publication No. 61-215623, polymerization methods using complex metal cyanide complex catalysts as shown in Japanese Patent Publication Nos. 46-27250, 59-15336, U.S. Patent Nos. 3278457, 3278458, 3278459, 3427256, 3427334, and 3427335, polymerization methods using catalysts consisting of polyphosphazene salts as exemplified in Japanese Patent Publication No. 10-273512, and polymerization methods using catalysts consisting of phosphazene compounds as exemplified in Japanese Patent Publication No. 11-060722. Polymerization using complex metal cyanide catalysts is more preferable due to reasons such as lower manufacturing costs and the ability to obtain polymers with a narrow molecular weight distribution.

[0129] As the reactive silicon group-containing polyoxyalkylene polymer (R), a polyoxyalkylene polymer containing other bonds such as urethane bonds and urea bonds in the main chain structure may be used, as long as the effects of the invention are not significantly impaired. A specific example of such a polymer is a polyurethane prepolymer.

[0130] Polyurethane prepolymers can be obtained by known methods, for example, by reacting a polyol compound with a polyisocyanate compound.

[0131] Examples of polyol compounds include polyether polyols, polyester polyols, polycarbonate polyols, and polyether polyester polyols.

[0132] Examples of polyisocyanate compounds include diphenylmethane diisocyanate, tolylene diisocyanate, xylylene diisocyanate, methylene-bis(cyclohexyl isocyanate), isophorone diisocyanate, and hexamethylene diisocyanate. The polyurethane prepolymer may have either hydroxyl or isocyanate groups at its ends.

[0133] In terms of obtaining a curable composition with excellent storage stability and workability, it is particularly preferable that the reactive silicon group-containing polyoxyalkylene polymer (R) is a polyoxyalkylene polymer that does not contain urethane bonds, urea bonds, ester bonds, or amide bonds in its main chain structure.

[0134] A reactive silicon group-containing polyoxyalkylene polymer (R) is preferably obtained by introducing reactive silicon groups into the polymer by any of the following methods (a) to (d): (a) Converting the terminal hydroxyl groups of a hydroxyl-terminated organic polymer to carbon-carbon unsaturated groups, then HSiR １ ３－ａ X ａ (In the formula, R １ A method for reacting X and a (where X and a are the same groups shown with respect to general formula (1)).

[0135] (b) OCN-W-SiR at the terminal hydroxyl group of the hydroxyl-terminated organic polymer １ ３－ａ X ａ (In the formula, W is a divalent organic group. R １ A method for reacting an isocyanate group-containing silane compound represented by (X, and a are the same groups shown in relation to general formula (1)).

[0136] (c) After converting the terminal hydroxyl groups of the hydroxyl-terminated organic polymer to carbon-carbon unsaturated groups, HS-W-SiR １ ３－ａ X ａ (In the formula, W is a divalent organic group. R １ A method for reacting a mercapto group-containing silane compound represented by (X, and a are the same groups shown with respect to general formula (1)).

[0137] (d) After reacting a hydroxyl-terminated organic polymer with a polyisocyanate compound to synthesize an NCO-terminated organic polymer, HNR-W-SiR １ ３－ａ X ａ (In the formula, W is a divalent organic group. R is a hydrogen atom or an alkyl group. １ X and a are the same groups shown with respect to general formula (1)) or HS-W-SiR １ ３－ａ Xａ (In the formula, W is a divalent organic group. R １ A method for reacting a silane compound represented by (X, and a are the same groups shown with respect to general formula (1)).

[0138] In the methods described in (a) and (c) above, examples of terminal carbon-carbon unsaturated groups include vinyl groups, allyl groups, methallyl groups, allenyl groups, and propargyl groups.

[0139] In each of the above methods, the reactive silicon group-containing polyoxyalkylene polymer (R) obtained using a silane compound in which W is represented by a methylene group is preferred in that it exhibits very high curability.

[0140] Method (a) is preferred because it tends to yield a reactive silicon group-containing polyoxyalkylene polymer (R) with good storage stability. Methods (b), (c), and (d) are preferred because they yield a high conversion rate with a relatively short reaction time.

[0141] The introduction of reactive silicon groups by method (a) has been proposed in various publications, including Japanese Patent Publication Nos. 45-36319, 46-12154, Japanese Patent Publication Nos. 50-156599, 54-6096, 55-13767, 55-13468, 57-164123, Japanese Patent Publication No. 3-2450, U.S. Patent No. 3632557, U.S. Patent No. 4345053, U.S. Patent No. 4366307, and U.S. Patent No. 4960844. Examples include those described in Japanese Patent Publication Nos. 61-197631, 61-215622, 61-215623, and 61-218632, which introduce reactive silicon groups to polyoxypropylene polymers with a high molecular weight and narrow molecular weight distribution, having a number average molecular weight of 6,000 or more and an Mw / Mn ratio of 1.6 or less, by hydrosilylation, etc., and those proposed in Japanese Patent Publication No. 3-72527.

[0142] As described in International Publication No. 2013 / 180203, using an organic polymer having two or more carbon-carbon unsaturated bonds at the end of one polymer chain, the polyoxyalkylene polymer (R) obtained by the above methods (a) and (c) has two or more reactive silicon groups at the end of one polymer chain. Such polyoxyalkylene polymers (R) exhibit high curability, and the resulting cured product can be expected to have high strength and high resilience.

[0143] When the curable composition according to this disclosure contains a reactive silicon group-containing polyoxyalkylene polymer (R), the amount of polymer (R) is preferably 1 to 50 parts by weight per 100 parts by weight of graft copolymer (P). If the amount is 1 part by weight or more, it is easy to achieve the effect of reducing the melt viscosity of the curable composition by incorporating polymer (R). Preferably, it is 5 parts by weight or more, more preferably 10 parts by weight or more, and even more preferably 15 parts by weight or more. Furthermore, if the content is 50 parts by weight or less, good strength after curing can be obtained. Preferably, it is 40 parts by weight or less, and more preferably 30 parts by weight or less.

[0144] <Silanol Condensation Catalyst> The curable composition according to this disclosure preferably contains a silanol condensation catalyst (also called a curing catalyst) to promote the condensation reaction of reactive silicon groups in the graft copolymer (P) and the (meth)acrylic acid ester polymer (Q). Examples of silanol condensation catalysts include organotin compounds, metal carboxylic acid salts, amine compounds, carboxylic acids, and alkoxy metals.

[0145] Specific examples of organotin compounds include dibutyltin dilaurate, dibutyltin dioctanoate, dibutyltin bis(butylmaleate), dibutyltin diacetate, dibutyltin oxide, dibutyltin bis(acetylacetonate), dioctyltin bis(acetylacetonate), dioctyltin dilaurate, dioctyltin distearate, dioctyltin diacetate, dioctyltin oxide, reaction products of dibutyltin oxide with silicate compounds, reaction products of dioctyltin oxide with silicate compounds, and reaction products of dibutyltin oxide with phthalate esters.

[0146] Specific examples of metal carboxylate salts include tin carboxylate, bismuth carboxylate, titanium carboxylate, zirconium carboxylate, and iron carboxylate. Various metals can be combined with the following carboxylic acids to form metal carboxylate salts.

[0147] Specific examples of amine compounds 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 butyl biguanide, 1-o-tolylbiguanide, and 1-phenylbiguanide; amino group-containing silane coupling agents; and ketimine compounds.

[0148] 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.

[0149] Specific examples of alkoxy metals include titanium compounds such as tetrabutyl titanate titanium tetrakis (acetylacetonate) and diisopropoxy titanium bis (ethylacetoacetate), aluminum compounds such as aluminum tris (acetylacetonate) and diisopropoxyaluminum ethylacetoacetate, and zirconium compounds such as zirconium tetrakis (acetylacetonate).

[0150] When using a silanol condensation catalyst, the amount used is preferably 0.001 to 20 parts by weight, more preferably 0.01 to 15 parts by weight, and even more preferably 0.01 to 10 parts by weight, per 100 parts by weight of the graft copolymer (P), from the viewpoint of promoting the condensation reaction of reactive silicon groups.

[0151] <Other Additives> In addition to the graft copolymer (P), (meth)acrylic acid ester polymer (Q), polyoxyalkylene polymer (R), and silanol condensation catalyst, the curable composition according to this disclosure may also contain plasticizers, fillers, adhesion promoters, rheology control agents, antioxidants, light stabilizers, ultraviolet absorbers, and other resins as additives.

[0152] Furthermore, various additives may be added to the curable composition according to this disclosure as needed for the purpose of adjusting the physical properties of the curable composition or the cured product. Examples of such additives include solvents, diluents, photocurable substances, oxygen-curable substances, surface modifiers, silicates, curing modifiers, radical inhibitors, metal deactivators, ozone degradation inhibitors, phosphorus-based peroxide decomposers, lubricants, pigments, antifungal agents, flame retardants, and foaming agents.

[0153] <Plasticizers> Plasticizers can be added to the curable composition. The addition of plasticizers can reduce the viscosity of the curable composition, making it easier to handle.

[0154] The plasticizer is not particularly limited, but examples include phthalate ester compounds such as dibutyl phthalate, diisononyl phthalate (DINP), diheptyl phthalate, di(2-ethylhexyl) phthalate, diisodecyl phthalate (DIDP), and butyl benzyl phthalate; terephthalate ester compounds such as bis(2-ethylhexyl)-1,4-benzenedicarboxylate; non-phthalate ester compounds such as 1,2-cyclohexanedicarboxylic acid diisononyl ester; and fats such as dioctyl adipicate, dioctyl sebacate, dibutyl sebacate, diisodecyl succinate, and tributyl acetylcitrate. Examples include polyvalent carboxylic acid ester compounds; unsaturated fatty acid ester compounds such as butyl oleate and methyl acetylricinoleate; phosphate ester compounds; trimellitic acid ester compounds; chlorinated paraffin; hydrocarbon oils such as alkyldiphenyl and partially hydrogenated terphenyl; process oils; epoxy plasticizers such as epoxidized soybean oil, epoxidized linseed oil, bis(2-ethylhexyl)-4,5-epoxycyclohexane-1,2-dicarbonoxylate (E-PS), epoxyoctyl stearate, epoxybutyl stearate and epoxybenzyl stearate; and alkyl sulfonic acid esters.

[0155] Polymeric plasticizers can also be used as plasticizers. Specific examples of polymeric plasticizers include vinyl polymers; polyester plasticizers; polyether polyols such as polyethylene glycol and polypropylene glycol with a number average molecular weight of 500 or more, and polyether-based plasticizers such as derivatives obtained by converting the hydroxyl groups of these polyether polyols to ester groups, ether groups, etc.; polystyrenes; polybutadiene, polybutene, polyisobutylene, butadiene-acrylonitrile, polychloroprene, etc. Among these, polymeric plasticizers are preferred, polyether-based plasticizers are more preferred, and polypropylene glycol is particularly preferred. Only one type of plasticizer may be used, or two or more types may be used in combination.

[0156] The amount of plasticizer added is preferably 5 to 150 parts by weight, more preferably 10 to 120 parts by weight, and particularly preferably 20 to 100 parts by weight, per 100 parts by weight of graft copolymer (P).

[0157] <Fillers> Fillers can be added to the curable composition. The strength of the cured product can be improved by adding fillers.

[0158] Examples of fillers include heavy calcium carbonate, colloidal calcium carbonate, magnesium carbonate, diatomaceous earth, clay, talc, titanium dioxide, fumed silica, settling silica, crystalline silica, fused silica, anhydrous silicic acid, hydrated silicic acid, alumina, carbon black, ferric oxide, aluminum powder, zinc oxide, activated zinc oxide, PVC powder, PMMA powder, glass fibers, and filaments. Organic balloons and inorganic balloons may be added to reduce the weight (low specific gravity) of the composition. Only one type of filler may be used, or two or more types may be used in combination.

[0159] The amount of filler added is preferably 1 to 300 parts by weight, and more preferably 10 to 250 parts by weight, per 100 parts by weight of graft copolymer (P).

[0160] <Adhesion-improving agent> An adhesion-improving agent may be added to the curable composition. As the adhesion-improving agent, a silane coupling agent or a reaction product of a silane coupling agent may be added.

[0161] Specific examples of silane coupling agents 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; as well as γ-isocyanatetopropyltrimethoxysilane, γ-isocyanatetopropyltriethoxysilane, and γ-iso Examples include isocyanate group-containing silanes such as cyanate-propylmethyldimethoxysilane, α-isocyanate-methyltrimethoxysilane, and α-isocyanate-methyldimethoxymethylsilane; 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. Reaction products of various silane coupling agents can also be used. The adhesion promoter may be used alone or in mixture of two or more types.

[0162] The amount of adhesion-improving agent added is preferably 0.1 to 20 parts by weight, and more preferably 0.5 to 10 parts by weight, per 100 parts by weight of graft copolymer (P).

[0163] <Rheology Control Agent> Rheology control agents may be added to the curable composition as needed to prevent sagging and improve workability.

[0164] The rheology control agents are not particularly limited, but examples include fatty acid amide waxes, hydrogenated castor oil derivatives; metal soaps such as calcium stearate, aluminum stearate, and barium stearate; dry silica, wet silica, etc. These rheology control agents may be used alone or in combination of two or more.

[0165] The amount of rheology control agent added is preferably 0.1 to 20 parts by weight per 100 parts by weight of graft copolymer (P).

[0166] <Antioxidants> Antioxidants (anti-aging agents) can be used in the curable composition. Using antioxidants 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 Japanese Patent Publication No. 4-283259 and Japanese Patent Publication No. 9-194731. The amount of antioxidant added is preferably 0.1 to 10 parts by weight, and more preferably 0.2 to 5 parts by weight, per 100 parts by weight of the graft copolymer (P).

[0167] <Light stabilizers> Light stabilizers can be used in the curable composition. Using light stabilizers can prevent photo-oxidative degradation of the cured product. Examples of light stabilizers include benzotriazole-based, hindered amine-based, and benzoate-based compounds, but hindered amine-based compounds are particularly preferred. The amount of light stabilizer to be added is preferably 0.1 to 10 parts by weight, and more preferably 0.2 to 5 parts by weight, per 100 parts by weight of the graft copolymer (P).

[0168] <UV Absorbers> UV absorbers can be used in the curable composition. Using UV absorbers can improve the surface weather resistance of the cured product. Examples of UV absorbers include benzophenone-based, benzotriazole-based, salicylate-based, substituted tolyl-based, and metal chelate compounds, but benzotriazole-based compounds are particularly preferred, and examples include commercially available products such as Chinuvin P, Chinuvin 213, Chinuvin 234, Chinuvin 326, Chinuvin 327, Chinuvin 328, Chinuvin 329, and Chinuvin 571 (all manufactured by BASF). The amount of UV absorber to be added is preferably 0.1 to 10 parts by weight, and more preferably 0.2 to 5 parts by weight, per 100 parts by weight of graft copolymer (P).

[0169] <Tackifying Resin> The curable composition according to this disclosure may contain a tackifying resin. A general tackifying resin can be used, and specific examples are not particularly limited, but include: terpene resins such as terpene resins, aromatically modified terpene resins, hydrogenated terpene resins, and terpene-phenol resins; phenol resins, alkylphenol resins, modified phenol resins (e.g., cashew oil modified phenol resins, tall oil modified phenol resins, etc.), xylene-phenol resins, cyclopentadiene-phenol resins, and coumarone indene resins; rosin resins such as gum rosin, tall oil rosin, wood rosin, hydrogenated rosin, disproportionated rosin, polymerized rosin, maleated rosin, rosin-glycerin esters, and hydrogenated rosin-glycerin esters; aromatic hydrocarbon resins such as xylene resins, low molecular weight polystyrene resins, styrene copolymer resins, styrene block copolymers and their hydrogenated products; petroleum resins such as petroleum resins (e.g., C5 hydrocarbon resins, C9 hydrocarbon resins, C5C9 hydrocarbon copolymer resins, etc.) and hydrogenated petroleum resins; and DCPD resins. You may use only one type of tackifying resin, or you may use two or more types in combination.

[0170] The amount of tackifying resin added is preferably 1 to 100 parts by weight per 100 parts by weight of graft copolymer (P). However, the curable composition according to this disclosure may substantially not contain tackifying resin, and the amount added may be less than 1 part by weight or less than 0.1 parts by weight per 100 parts by weight of graft copolymer (P).

[0171] <Epoxy resin> The curable composition according to this disclosure may contain an epoxy resin. While not limited to specific examples, examples of epoxy resins include epichlorohydrin-bisphenol A type epoxy resin, epichlorohydrin-bisphenol F type epoxy resin, flame-retardant epoxy resins such as glycidyl ether of tetrabromobisphenol A, novolac type epoxy resin, hydrogenated bisphenol A type epoxy resin, glycidyl ether type epoxy resin of bisphenol A propylene oxide adduct, p-oxybenzoic acid glycidyl ether ester type epoxy resin, m-aminophenol type epoxy resin, diaminodiphenylmethane type epoxy resin, urethane-modified epoxy resin, various alicyclic epoxy resins, N,N-diglycidylaniline, N,N-diglycidyl-o-toluidine, triglycidyl isocyanurate, polyalkylene glycol diglycidyl ether, glycidyl ether of polyhydric alcohols such as glycerin, hydantoin type epoxy resin, and epoxidized compounds of unsaturated polymers such as petroleum resin. One type of epoxy resin may be used, or two or more types may be used in combination.

[0172] The amount of epoxy resin blended is preferably 10 to 100 parts by weight per 100 parts by weight of graft copolymer (P). However, the curable composition according to this disclosure may not substantially contain epoxy resin, and the amount blended may be less than 10 parts by weight or less than 1 part by weight per 100 parts by weight of graft copolymer (P).

[0173] The curable composition according to this disclosure can be prepared as a one-component type that hardens upon contact with moisture in the air after application by pre-mixing all components and storing them in a sealed container. In this case, it is preferable to dehydrate and dry any components containing moisture before use, or to dehydrate them by reducing pressure during mixing.

[0174] For dehydration and drying, suitable methods include heat drying for solid materials such as powders, and vacuum dehydration or dehydration using synthetic zeolite, activated alumina, silica gel, quicklime, magnesium oxide, etc., for liquid materials. Alternatively, a small amount of isocyanate compound may be added and the isocyanate group may be reacted with water to dehydrate the material. Oxazolidine compounds such as 3-ethyl-2-methyl-2-(3-methylbutyl)-1,3-oxazolidine may also be added and reacted with water to dehydrate the material.

[0175] In addition to these dehydration and drying methods, storage stability can be further improved by adding lower alcohols such as methanol and ethanol, or alkoxysilane compounds. Examples of the alkoxysilane compounds include methyltrimethoxysilane, decyltrimethoxysilane, phenyltrimethoxysilane, n-propyltrimethoxysilane, vinyltrimethoxysilane, vinylmethyldimethoxysilane, γ-mercaptopropylmethyldimethoxysilane, γ-mercaptopropylmethyldiethoxysilane, and γ-glycidoxypropyltrimethoxysilane.

[0176] The amount of dehydrating agent, particularly the alkoxysilane compound, used is preferably 0.1 to 20 parts by weight, and more preferably 0.5 to 10 parts by weight, per 100 parts by weight of the graft copolymer (P).

[0177] There are no particular limitations on the method for preparing the curable composition relating to this disclosure. For example, conventional methods such as blending the above components and kneading them at room temperature or under heating using a mixer, roll, kneader, etc., or dissolving and mixing the above components using a small amount of a suitable solvent can be employed.

[0178] The curable composition according to this disclosure can exhibit good adhesion to various substrates such as plastics, metals, and composite materials. Furthermore, when used as an adhesive for non-polar materials such as polypropylene or engineering plastics with rigid molecular chains such as polyphenylene sulfide, the substrate can be pre-treated by known methods to enhance adhesion to these substrates and obtain stable adhesive strength. For example, surface treatment techniques such as sanding, flame treatment, corona discharge, arc discharge, and plasma treatment can be used. Plasma treatment is preferred because it causes less damage to the substrate and provides stable adhesion. These surface treatments are also effective in removing mold release agents that remain on the substrate surface after molding.

[0179] Since the cured product obtained by curing the curable composition according to this disclosure has good adhesion to various substrates, the curable composition can be used as an adhesive, sealant, or tack. In particular, since the curable composition according to this disclosure is solid at room temperature but becomes fluid when heated and melted, allowing it to be applied to a substrate, it can be suitably used as a hot-melt type curable composition, especially a hot-melt type adhesive.

[0180] When applying the curable composition according to this disclosure to a substrate, it is preferable to heat it to a high temperature to reduce its viscosity in order to ensure workability. The temperature at which this is done is preferably around 70 to 180°C, more preferably 90 to 160°C, and even more preferably 100 to 150°C. The method of heating is not particularly limited, and conventionally known methods can be used.

[0181] The curable composition according to this disclosure can exhibit desired physical properties by undergoing a long curing (curing) process after bonding the adherends. The conditions for the curing (curing) process are not particularly limited, but examples include a temperature of 5 to 90°C and a duration of 24 hours to 1 week.

[0182] The curable composition according to this disclosure can be used as a reactive hot-melt adhesive. This curable composition is suitable as an adhesive for joining panels of buses, trailers, trains, etc., as an adhesive for joining displays and housings in smartphones, tablet devices, and laptop computers, as an adhesive for clothing, and for joining dissimilar materials such as aluminum-steel, steel-composite, and aluminum-composite. When joining dissimilar materials, it is preferable to cover the joint with a sealer to prevent corrosion. As the sealer, a polymer having reactive silicon groups as shown in this application can be used.

[0183] More specifically, the curable composition according to this disclosure is preferably used as an adhesive in automotive parts such as vehicle panels, large vehicle parts such as trucks and buses, train car parts, aircraft parts, ship parts, electrical parts, and various machine parts.

[0184] The following sections list preferred embodiments of this disclosure, but the present invention is not limited to these sections. [Section 1] General formula (1): -SiR １ ３－ａ X ａ (1) (wherein, R １A curable composition comprising: 100 parts by weight of a graft copolymer (P) in which a (meth)acrylic acid ester polymer block (A) having a reactive silicon group represented by the general formula (1) and a polyoxyalkylene polymer block (B) having a number average molecular weight of 1,000 or more are bonded in the order A-B-A, and 5 to 65 parts by weight of a (meth)acrylic acid ester polymer (Q) having a reactive silicon group represented by the general formula (1). [Item 2] The curable composition according to Item 1, wherein the reactive silicon group of the graft copolymer (P) is a trimethoxysilyl group. [Item 3] The curable composition according to Item 1 or 2, wherein the reactive silicon group of the (meth)acrylic acid ester polymer (Q) is a dimethoxymethylsilyl group. [Item 4] The curable composition according to any one of Items 1 to 3, wherein the polymer block (A) comprises a constituent unit derived from (meth)acrylic acid ester (a1) and a constituent unit derived from a chain transfer agent (a2) having a mercapto group, and the sulfur atom concentration derived from the chain transfer agent (a2) is 4,000 to 9,000 ppm in the graft copolymer (P). [Item 5] The curable composition according to any one of Items 1 to 4, wherein the polymer block (A) contains an alkyl (meth)acrylic acid ester having 10 to 30 carbon atoms in the alkyl group, and the content of this alkyl group is 0 to 8% by weight in the graft copolymer (P). [Item 6] The curable composition according to any one of Items 1 to 5, wherein the polymer block (A) contains an alkyl (meth)acrylic acid ester with 3 or fewer carbon atoms in the alkyl group, and the content of this alkyl group is 30 to 60% by weight in the graft copolymer (P). [Item 7] A curable composition according to any one of Items 1 to 6, wherein the number average molecular weight of the (meth)acrylic acid ester polymer (Q) is 1,000 to 4,500. [Item 8] A curable composition according to any one of Items 1 to 7, further containing a polyoxyalkylene polymer (R) having a reactive silicon group represented by the general formula (1). [Item 9] A hot-melt type curable composition comprising the curable composition according to any one of Items 1 to 8. [Item 10] A cured product obtained by curing the curable composition according to any one of Items 1 to 8.

[0185] The present invention will be specifically described below with reference to examples, but these examples are not intended to limit the present invention.

[0186] 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-8120GPC Column: Tosoh TSK-GEL H-type solvent: THF Molecular weight: Polystyrene equivalent Measurement temperature: 40°C

[0187] (Sulfur atom concentration) The sulfur atom concentration is a theoretical value calculated from the total amount of components used in the production of the graft copolymer (P) and the amount of chain transfer agent (a2) having a mercapto group.

[0188] (Synthesis Example 1) Using polyoxypropylene glycol with a number average molecular weight of approximately 4,020 (end group molecular weight 2,980) as an initiator, polymerization of propylene oxide was carried out with a zinc hexacyanocobaltate grime complex catalyst to obtain polyoxypropylene having hydroxyl groups at both ends, a number average molecular weight of 21,100 (end group molecular weight 13,600), and a molecular weight distribution Mw / Mn = 1.21. 60 ppm of U-360 (dibutyltin bis(isooctyl mercaptopropionate, Nitto Chemical Co., Ltd.)) was added to the obtained polyoxypropylene, and 0.93 equivalents of Karenz AOI (2-isocyanate ethyl acrylate, Showa Denko K.K.) were added dropwise to the hydroxyl groups of the polyoxypropylene. The reaction was carried out at 90°C for 1 hour in a nitrogen atmosphere to obtain a polyoxyalkylene polymer (a4-1) having acryloyl groups at both ends (i.e., approximately 2 acryloyl groups in one polymer molecule), a number-average molecular weight of 21,100, and a weight-average molecular weight of 24,930.

[0189] (Synthesis Example 2) Using polyoxypropylene glycol with a number average molecular weight of approximately 4,020 (end group molecular weight of 2,980) as an initiator, propylene oxide was polymerized with a zinc hexacyanocobaltate grime complex catalyst to obtain polyoxypropylene having hydroxyl groups at both ends, a number average molecular weight of 14,600 (end group molecular weight of 9,130), and a molecular weight distribution Mw / Mn = 1.15. 60 ppm of U-360 was added to the obtained polyoxypropylene, and 0.95 equivalents of Karenz AOI were added dropwise to the hydroxyl groups of the polyoxypropylene. The reaction was carried out at 90°C for 1 hour in a nitrogen atmosphere to obtain a polyoxyalkylene polymer (a4-2) having acryloyl groups at both ends (i.e., approximately 2 acryloyl groups per polymer molecule), a number average molecular weight of 14,600, and a weight average molecular weight of 16,790.

[0190] (Synthesis Example 3) 42.2 parts by weight of butyl acetate was placed in a four-necked flask equipped with a stirrer and heated to 115°C under a nitrogen atmosphere. A mixed solution prepared by dissolving 43.9 parts by weight of methyl methacrylate, 0.5 parts by weight of butyl acrylate, 48.4 parts by weight of the polyfunctional macromonomer (a4-1) prepared in Synthesis Example 1, 4.0 parts by weight of 3-methacryloxypropyltrimethoxysilane, 3.2 parts by weight of 3-mercaptopropyltrimethoxysilane, and 0.9 parts by weight of 2,2'-azobis(2-methylbutyronitrile) in 17.1 parts by weight of butyl acetate was added dropwise over 3 hours. Furthermore, a mixed solution of 0.3 parts by weight of 2,2'-azobis(2-methylbutyronitrile) dissolved in 5.7 parts by weight of butyl acetate was added, and polymerization was carried out at 115°C for 2 hours to obtain a butyl acetate solution (60% solids) of a reactive silicon group-containing graft copolymer (P-1) with a number average molecular weight of 3,410 (GPC molecular weight). The polyfunctional macromonomer equivalent of the solids in this solution was 0.023 mmol / g, the reactive silicon group equivalent was 0.32 mmol / g, and the sulfur atom concentration was 5,217 ppm.

[0191] (Synthesis Example 4) 42.2 parts by weight of butyl acetate was placed in a four-necked flask equipped with a stirrer and heated to 115°C under a nitrogen atmosphere. A mixed solution prepared by dissolving 39.9 parts by weight of methyl methacrylate, 6.0 parts by weight of butyl acrylate, 48.4 parts by weight of the polyfunctional macromonomer (a4-2) prepared in Synthesis Example 2, 2.5 parts by weight of 3-methacryloxypropyltrimethoxysilane, 3.2 parts by weight of 3-mercaptopropyltrimethoxysilane, and 0.9 parts by weight of 2,2'-azobis(2-methylbutyronitrile) in 17.1 parts by weight of butyl acetate was added dropwise over 3 hours. Furthermore, a mixed solution of 0.3 parts by weight of 2,2'-azobis(2-methylbutyronitrile) dissolved in 5.7 parts by weight of butyl acetate was added, and polymerization was carried out at 115°C for 2 hours to obtain a butyl acetate solution (60% solids) of a reactive silicon group-containing graft copolymer (P-2) with a number average molecular weight of 3,960 (GPC molecular weight). The polyfunctional macromonomer equivalent of the solids in this solution was 0.033 mmol / g, the reactive silicon group equivalent was 0.26 mmol / g, and the sulfur atom concentration was 5,217 ppm.

[0192] (Synthesis Example 5) 34.8 parts by weight of butyl acetate was placed in a four-necked flask equipped with a stirrer and heated to 115°C under a nitrogen atmosphere. A mixed solution of 72.0 parts by weight of methyl methacrylate, 8.0 parts by weight of butyl acrylate, 14.0 parts by weight of stearyl methacrylate, 6.0 parts by weight of 3-methacryloxypropyl dimethoxymethylsilane, 7.9 parts by weight of 3-mercaptopropyl dimethoxymethylsilane, and 2.7 parts by weight of 2,2'-azobis(2-methylbutyronitrile) dissolved in 31.1 parts by weight of butyl acetate was added dropwise over 3 hours. A mixed solution of 0.3 parts by weight of 2,2'-azobis(2-methylbutyronitrile) dissolved in 8.2 parts by weight of butyl acetate was added and polymerization was carried out at 115°C for 2 hours to obtain a butyl acetate solution (60% solids content) of a reactive silicon group-containing (meth)acrylic acid ester copolymer (Q-1) with a number average molecular weight of 1,810 (GPC molecular weight). The reactive silicon group equivalent of the solid content of the solution is 0.70 mmol / g.

[0193] (Synthesis Example 6) 39.0 parts by weight of butyl acetate was placed in a four-necked flask equipped with a stirrer and heated to 115°C under a nitrogen atmosphere. A mixed solution of 30.0 parts by weight of methyl methacrylate, 38.2 parts by weight of butyl acrylate, 25.0 parts by weight of 2-ethylhexyl acrylate, 5.0 parts by weight of 3-methacryloxypropyltrimethoxysilane, 1.8 parts by weight of 3-mercaptopropyltrimethoxysilane, and 0.9 parts by weight of 2,2'-azobis(2-methylbutyronitrile) dissolved in 20.7 parts by weight of butyl acetate was added dropwise over 3 hours. A mixed solution of 0.3 parts by weight of 2,2'-azobis(2-methylbutyronitrile) dissolved in 13.5 parts by weight of butyl acetate was added and polymerization was carried out at 115°C for 2 hours to obtain a butyl acetate solution (60% solids content) of a reactive silicon group-containing (meth)acrylic acid ester copolymer (Q-2) with a number average molecular weight of 5,000 (GPC molecular weight). The reactive silicon group equivalent of the solid content of the solution is 0.29 mmol / g.

[0194] (Synthesis Example 7) Using polyoxypropylene glycol with a number average molecular weight of approximately 2,000 as an initiator, propylene oxide was polymerized with a zinc hexacyanocobaltate grime complex catalyst to obtain polyoxypropylene with a number average molecular weight of 14,600 (end group equivalent molecular weight of 9,100) and a molecular weight distribution Mw / Mn = 1.21, with hydroxyl groups at both ends. 1.2 molar equivalents of sodium methoxide in a 28% methanol solution were added to the hydroxyl groups of the obtained hydroxyl-terminated polyoxypropylene. After removing methanol by vacuum defoliation, 1.5 molar equivalents of allyl chloride were added to the hydroxyl groups of the hydroxyl-terminated polyoxypropylene and the reaction was carried out at 130°C for 2 hours. To 100 parts by weight of the obtained unpurified allyl-terminated polyoxypropylene, 300 parts by weight of n-hexane and 300 parts by weight of water were mixed and stirred. After removing the water by centrifugation, another 300 parts by weight of water was added to the obtained hexane solution and stirred. After removing the water again by centrifugation, the hexane was removed by defloration under reduced pressure. To 100 parts by weight of the obtained polyoxypropylene, 72 ppm of platinum divinyldisiloxane complex (3% by weight of isopropanol solution in terms of platinum) was added, and 2.1 parts by weight of trimethoxysilane were slowly added dropwise while stirring. The mixed solution was reacted at 90°C for 2 hours, and the unreacted trimethoxysilane was removed by distillation under reduced pressure to obtain a linear reactive silicon-containing polyoxypropylene polymer (R-1) having an average of 1.6 trimethoxysilyl groups per molecule and a number-average molecular weight of 14,600.

[0195] (Synthesis Example 8) Using polyoxypropylene glycol with a number average molecular weight of approximately 2,000 as an initiator, propylene oxide was polymerized with a zinc hexacyanocobaltate grime complex catalyst to obtain polyoxypropylene with a number average molecular weight of 14,600 (end group equivalent molecular weight of 9,100) and a molecular weight distribution Mw / Mn = 1.21, with hydroxyl groups at both ends. 1.2 molar equivalents of sodium methoxide in a 28% methanol solution were added to the hydroxyl groups of the obtained hydroxyl-terminated polyoxypropylene. After removing methanol by vacuum defoliation, 1.5 molar equivalents of allyl chloride were added to the hydroxyl groups of the hydroxyl-terminated polyoxypropylene and the reaction was carried out at 130°C for 2 hours. To 100 parts by weight of the obtained unpurified allyl-terminated polyoxypropylene, 300 parts by weight of n-hexane and 300 parts by weight of water were mixed and stirred. After removing the water by centrifugation, another 300 parts by weight of water was added to the obtained hexane solution and stirred. After removing the water again by centrifugation, the hexane was removed by defloration under reduced pressure. To 100 parts by weight of the obtained polyoxypropylene, 36 ppm of platinum divinyldisiloxane complex (3% by weight of isopropanol solution in terms of platinum) was added, and 1.8 parts by weight of dimethylmethylsilane was slowly added dropwise while stirring. The mixed solution was reacted at 90°C for 2 hours, and the unreacted dimethoxymethylsilane was removed by distillation under reduced pressure to obtain a linear reactive silicon-containing polyoxypropylene polymer (R-2) having an average of 1.6 dimethoxymethylsilyl groups per molecule and a number-average molecular weight of 14,600.

[0196] (Synthesis Example 9) 39.0 parts by weight of butyl acetate was placed in a four-necked flask equipped with a stirrer and heated to 115°C under a nitrogen atmosphere. A mixed solution of 65.0 parts by weight of methyl methacrylate, 25.0 parts by weight of 2-ethylhexyl acrylate, 7.4 parts by weight of n-dodecyl mercaptan, and 1.8 parts by weight of 2,2'-azobis(2-methylbutyronitrile) dissolved in 20.7 parts by weight of butyl acetate was added dropwise over 3 hours. A mixed solution of 0.30 parts by weight of 2,2'-azobis(2-methylbutyronitrile) dissolved in 13.5 parts by weight of butyl acetate was added and polymerization was carried out at 115°C for 2 hours to obtain a butyl acetate solution (60% solids content) of a (meth)acrylic acid ester copolymer (S-1) with a number average molecular weight of 1,950 (GPC molecular weight).

[0197] (Example 1) A butyl acetate solution of the reactive silicon group-containing graft copolymer (P-1) obtained in Synthesis Example 3 and a butyl acetate solution of the reactive silicon group-containing (meth)acrylic acid ester copolymer (Q-1) obtained in Synthesis Example 5 were mixed in a solid content ratio of 100 parts by weight / 15 parts by weight, and the mixture was heated and defoliated to obtain a polymer mixture that was solid at room temperature. The obtained polymer mixture was heated to 140°C, and 1 part by weight of KBM-3103C (decyltrimethoxysilane, manufactured by Shin-Etsu Chemical Co., Ltd.), 2 parts by weight of Dynasylan 1146 (diaminosilane-containing silane oligomer, manufactured by Evonik), and 0.2 parts by weight of U-810 (dioctyl tin dilaurate, manufactured by Nitto Chemical Co., Ltd.) were added and mixed to obtain a hot-melt curable composition.

[0198] (Complex Viscosity and Complex Modulus) The obtained hot-melt curable composition was subjected to dynamic viscoelasticity measurements while cooling from 150°C to 10°C using a parallel disc plate with a diameter of 20 mm as a jig and a gap of 0.5 mm. The complex viscosity was recorded at 120°C, and the complex modulus was recorded at 23°C. A rheometer (DHR-2) manufactured by TA Instruments was used. The results are shown in Table 1.

[0199] (Tensile Properties) Using the obtained hot-melt curable composition, a sheet approximately 2 mm thick was prepared and cured for 7 days under conditions of 23°C and 50% RH. The obtained sheet was punched out into a No. 3 dumbbell shape (JIS K 6251), and a tensile strength test was performed at an elongation rate of 50 mm / min to measure the strength at break (TB) and elongation at break (EB). The apparatus used was an Autograph (AGS-X) manufactured by Shimadzu Corporation. The results are shown in Table 1.

[0200] (Example 2) A hot-melt curable composition was prepared in the same manner as in Example 1, except that the solid content ratio of the butyl acetate solution of the reactive silicon group-containing graft copolymer (P-1) and the butyl acetate solution of the reactive silicon group-containing (meth)acrylic acid ester copolymer (Q-1) was changed to 100 / 60, and KBM-603 ((N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, manufactured by Shin-Etsu Chemical Co., Ltd.) was used instead of Dynasylan 1146, and the same evaluation was performed.

[0201] (Example 3) A hot-melt curable composition was prepared in the same manner as in Example 1, except that a butyl acetate solution of the reactive silicon group-containing (meth)acrylic acid ester copolymer (Q-2) obtained in Synthesis Example 6 was used instead of a butyl acetate solution of the reactive silicon group-containing (meth)acrylic acid ester copolymer (Q-1), and the same evaluation was performed.

[0202] (Example 4) A hot-melt curable composition was prepared in the same manner as in Example 2, except that a butyl acetate solution of the reactive silicon group-containing graft copolymer (P-1), a butyl acetate solution of the reactive silicon group-containing (meth)acrylic acid ester copolymer (Q-1), and the reactive silicon group-containing polyoxyalkylene polymer (R-1) obtained in Synthesis Example 7 were used in a solid content ratio of 100 / 10 / 15, and the composition was evaluated in the same manner.

[0203] (Example 5) A hot-melt curable composition was prepared in the same manner as in Example 2, except that a butyl acetate solution of the reactive silicon group-containing graft copolymer (P-1), a butyl acetate solution of the reactive silicon group-containing (meth)acrylic acid ester copolymer (Q-1), and the reactive silicon group-containing polyoxyalkylene polymer (R-2) obtained in Synthesis Example 8 were used in a solid content ratio of 100 / 10 / 15, and the composition was evaluated in the same manner.

[0204] (Comparative Example 1) A hot-melt curable composition was prepared in the same manner as in Example 2, except that a butyl acetate solution of a reactive silicon group-containing (meth)acrylic acid ester copolymer (Q-1) was not used, and only a butyl acetate solution of a reactive silicon group-containing graft copolymer (P-1) was used, and the same evaluation was performed.

[0205] (Comparative Example 2) Except for changing the solid content ratio of the butyl acetate solution of the reactive silicon group-containing graft copolymer (P-1) to the butyl acetate solution of the reactive silicon group-containing (meth)acrylic acid ester copolymer (Q-1) to 100 / 100, a hot-melt type curable composition was prepared in the same manner as in Example 2 and evaluated in the same way.

[0206] (Comparative Example 4) A hot-melt curable composition was prepared in the same manner as in Example 2, except that a butyl acetate solution of a reactive silicon group-containing (meth)acrylic acid ester copolymer (Q-1) was not used, and a butyl acetate solution of a reactive silicon group-containing graft copolymer (P-1) and a reactive silicon group-containing polyoxyalkylene polymer (R-1) were used in a solid content ratio of 100 / 60. The same evaluation was then performed.

[0207] (Comparative Example 5) A hot-melt curable composition was prepared in the same manner as in Example 2, except that a butyl acetate solution of the reactive silicon group-containing (meth)acrylic acid ester copolymer (Q-1) was not used, and a butyl acetate solution of the reactive silicon group-containing graft copolymer (P-1) and a butyl acetate solution of the (meth)acrylic acid ester copolymer (S-1) obtained in Synthesis Example 9 were used in a solid content ratio of 100 / 15. The same evaluation was then performed.

[0208]

[0209] Table 1 shows that the hot-melt curable compositions of Examples 1 to 5, which contain both a reactive silicon group-containing graft copolymer (P) and a reactive silicon group-containing (meth)acrylic acid ester copolymer (Q), exhibit a lower viscosity during heating and melting (complex viscosity at 120°C) compared to Comparative Example 1, which does not contain the reactive silicon group-containing (meth)acrylic acid ester copolymer (Q). Furthermore, the elongation (EB) after curing is either equal to or greater than that of the two compositions, or maintains its value without significant decrease.

[0210] On the other hand, in Comparative Example 2, where the blending ratio of the reactive silicon group-containing graft copolymer (P) and the reactive silicon group-containing (meth)acrylic acid ester copolymer (Q) was 100 / 100, the elongation after curing was halved compared to Comparative Example 1. Furthermore, in Comparative Examples 4 and 5, which did not contain the reactive silicon group-containing (meth)acrylic acid ester copolymer (Q) but contained a reactive silicon group-containing polyoxyalkylene polymer (R) or a (meth)acrylic acid ester copolymer (S) without reactive silicon groups, the elongation after curing was about 60% of that of Comparative Example 1.

[0211] (Example 6) A hot-melt curable composition was prepared in the same manner as in Example 1, except that a butyl acetate solution of the reactive silicon group-containing graft copolymer (P-2) obtained in Synthesis Example 4 was used instead of a butyl acetate solution of the reactive silicon group-containing graft copolymer (P-1), and KBM-603 was used instead of Dynasylan 1146, and the same evaluation was performed.

[0212] (Example 7) A hot-melt curable composition was prepared in the same manner as in Example 6, except that a butyl acetate solution of the reactive silicon group-containing (meth)acrylic acid ester copolymer (Q-2) obtained in Synthesis Example 6 was used instead of a butyl acetate solution of the reactive silicon group-containing (meth)acrylic acid ester copolymer (Q-1), and the same evaluation was performed.

[0213] (Example 8) A hot-melt curable composition was prepared in the same manner as in Example 6, except that a butyl acetate solution of a reactive silicon group-containing graft copolymer (P-2), a butyl acetate solution of a reactive silicon group-containing (meth)acrylic acid ester copolymer (Q-1), and a reactive silicon group-containing polyoxyalkylene polymer (R-1) were used in a solid content ratio of 100 / 15 / 10, and the same evaluation was performed.

[0214] (Example 9) A hot-melt curable composition was prepared in the same manner as in Example 8, except that a reactive silicon group-containing polyoxyalkylene polymer (R-2) was used instead of the reactive silicon group-containing polyoxyalkylene polymer (R-1), and the same evaluation was performed.

[0215] (Comparative Example 3) A hot-melt curable composition was prepared in the same manner as in Example 6, except that a butyl acetate solution of a reactive silicon group-containing (meth)acrylic acid ester copolymer (Q-1) was not used, and only a butyl acetate solution of a reactive silicon group-containing graft copolymer (P-2) was used, and the same evaluation was performed.

[0216]

[0217] Table 2 shows that the hot-melt curable compositions of Examples 6 to 9, which contain both the reactive silicon group-containing graft copolymer (P) and the reactive silicon group-containing (meth)acrylic acid ester copolymer (Q), show a decrease in viscosity during heating and melting (complex viscosity at 120°C) compared to Comparative Example 3, which does not contain the reactive silicon group-containing (meth)acrylic acid ester copolymer (Q). Furthermore, the elongation (EB) after curing is either equivalent to or greater than that of Comparative Example 3, or does not decrease significantly and remains constant.

Claims

1. General formula (1): -SiR １ ３－ａ X ａ (1) (wherein, R １ A curable composition comprising: 100 parts by weight of a graft copolymer (P) in which a (meth)acrylic acid ester polymer block (A) having a reactive silicon group represented by the general formula (1) and a polyoxyalkylene polymer block (B) having a number average molecular weight of 1,000 or more are bonded in the order A-B-A; and 5 to 65 parts by weight of a (meth)acrylic acid ester polymer (Q) having a reactive silicon group represented by the general formula (1).

2. The curable composition according to claim 1, wherein the reactive silicon group of the graft copolymer (P) is a trimethoxysilyl group.

3. The curable composition according to claim 1 or 2, wherein the reactive silicon group of the (meth)acrylic acid ester polymer (Q) is a dimethoxymethylsilyl group.

4. The curable composition according to claim 1 or 2, wherein the polymer block (A) comprises a constituent unit derived from (meth)acrylic acid ester (a1) and a constituent unit derived from a chain transfer agent (a2) having a mercapto group, and the sulfur atom concentration derived from the chain transfer agent (a2) is 4,000 to 9,000 ppm in the graft copolymer (P).

5. The curable composition according to claim 1 or 2, wherein the content of alkyl (meth)acrylate ester having 10 to 30 C1 of the alkyl group in the polymer block (A) is 0 to 8% by weight in the graft copolymer (P).

6. The curable composition according to claim 1 or 2, wherein the content of alkyl (meth)acrylate esters with three or fewer C atoms in the polymer block (A) is 30 to 60% by weight in the graft copolymer (P).

7. The curable composition according to claim 1 or 2, wherein the number average molecular weight of the (meth)acrylic acid ester polymer (Q) is 1,000 to 4,500.

8. The curable composition according to claim 1 or 2, further comprising a polyoxyalkylene polymer (R) having a reactive silicon group represented by the general formula (1).

9. A hot-melt type curable composition comprising the curable composition according to claim 1 or 2.

10. A cured product obtained by curing the curable composition according to claim 1 or 2.

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