Curable composition, and method for producing the curable composition

Abstract

To provide a method for producing a curable composition capable of producing a curable composition which contains a polyoxyalkylene-based polymer having a reactive silicon group, a (meth)acrylic polymer having a reactive silicon group, a hindered amine-based photostabilizer, and a hindered phenolic antioxidant, and gives a cured product that is difficult to be colored by a weathering test and generate tackiness thereon.SOLUTION: When a curable composition containing a polyoxyalkylene-based polymer (A) having a reactive silicon group, a (meth)acrylic polymer (B) having a reactive silicon group, a hindered amine-based photostabilizer (C), and a hindered phenolic antioxidant (D) is produced, a liquid resin component which contains at least one kind of the polyoxyalkylene-based polymer (A) and a (meth)acrylic polymer (B), and is 50°C or higher, and a melted hindered phenolic antioxidant are mixed.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a curable composition comprising (A) a polyoxyalkylene polymer having a reactive silicon group, (B) a (meth)acrylic polymer having a reactive silicon group, (C) a hindered amine light stabilizer, and (D) a hindered phenol antioxidant, and a method for producing the curable composition. [Background technology]

[0002] Organic polymers having at least one reactive silicon group in the molecule can be crosslinked even at room temperature by forming siloxane bonds accompanied by hydrolysis of the silyl groups due to moisture, etc. It is known that organic polymers having reactive silicon groups have the property of giving rubber-like cured products through such crosslinking reactions.

[0003] Among organic polymers having reactive silicon groups, polyoxyalkylene polymers having reactive silicon groups are widely used in construction sealants and industrial sealants, where the curable compositions containing the polyoxyalkylene polymers having reactive silicon groups are required to have excellent long-term weather resistance.

[0004] For this reason, when producing a curable composition, a polyoxyalkylene polymer having a reactive silicon group is generally blended with a combination of an antioxidant, a light stabilizer, an ultraviolet absorber, etc. In particular, high-molecular-weight hindered amine light stabilizers are known to be effective in improving weather resistance (Patent Document 1). Also, it is generally known that hindered phenol antioxidants are effective in enhancing the light stabilizing effect of light stabilizers and improving heat resistance.

[0005] Another known method for improving the weather resistance of a cured product is to combine a (meth)acrylic polymer having a reactive silicon group and a polyoxyalkylene polymer having a reactive silicon group in a curable composition (Patent Document 2). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-006886 [Patent Document 2] Japanese Patent Application Publication No. 2024-002114 Summary of the Invention [Problem to be solved by the invention]

[0007] However, when a weather resistance test is performed on a cured product of a curable composition containing a polyoxyalkylene polymer having a reactive silicon group, a (meth)acrylic polymer having a reactive silicon group, a hindered amine light stabilizer, and a hindered phenol antioxidant, the cured product may become discolored or tack may occur on the surface of the cured product.

[0008] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a method for producing a curable composition that contains a polyoxyalkylene polymer having a reactive silicon group, a (meth)acrylic polymer having a reactive silicon group, a hindered amine light stabilizer, and a hindered phenol antioxidant, and that can produce a curable composition that gives a cured product that is resistant to discoloration and surface tackiness in a weather resistance test. [Means for solving the problem]

[0009] The present inventors have discovered that the above-mentioned problems can be solved by mixing a liquid resin component containing at least one of the polyoxyalkylene polymer (A) and the (meth)acrylic polymer (B), a hindered amine light stabilizer (C), and a hindered phenol antioxidant (D) at 50°C or higher with molten hindered phenol antioxidant (D), when producing a curable composition containing a polyoxyalkylene polymer (A) having a reactive silicon group, a (meth)acrylic polymer (B) having a reactive silicon group, a hindered amine light stabilizer (C), and a hindered phenol antioxidant (D), thereby completing the present invention.

[0010] More specifically, the present invention provides the following (1) to (6). (1) A method for producing a curable composition comprising a polyoxyalkylene polymer (A) having a reactive silicon group, a (meth)acrylic polymer (B) having a reactive silicon group, a hindered amine light stabilizer (C), and a hindered phenol antioxidant (D), the method comprising: the aforementioned production method includes mixing a liquid resin component containing at least one of a polyoxyalkylene polymer (A) and a (meth)acrylic polymer (B) and having a temperature of 50°C or higher with a molten hindered phenol-based antioxidant (D); The production method, wherein the (meth)acrylic polymer (B) contains a structural unit derived from a (meth)acrylic acid alkyl ester. (2) The number of moles N of hydroxy groups in the hindered phenol antioxidant (D) OH The number of moles N of nitrogen atoms contained in the hindered amine light stabilizer (C) relative to N Ratio of N N / N OH is 0.1 to 10. (3) Weight W of (meth)acrylic polymer (B) B The weight W of the polyoxyalkylene polymer (A) relative to A Ratio of W A / W B The manufacturing method according to (1) or (2), wherein the ratio is 20 / 80 to 80 / 20. (4) The curable composition was cured at 23°C and a relative humidity of 55% to obtain a 3 mm thick sheet-shaped test piece, and the illuminance was 435 mW / cm. 2 More than 470mW / cm 2 The cumulative light intensity is 10,000mJ / cm 2 More than 12,000mJ / cm 2 The manufacturing method according to any one of (1) to (3), wherein the cured product when irradiated with UV light has a rolling distance of more than 150 mm as measured according to ASTM D 3121. (5) A curable composition produced by the production method according to any one of (1) to (3). (6) The curable composition was cured at 23°C and a relative humidity of 55% to obtain a test piece of a 3 mm thick sheet-like cured product, and the illuminance was 435 mW / cm. 2 More than 470mW / cm 2 The cumulative light intensity is 10,000mJ / cm 2 More than 12,000mJ / cm 2 The curable composition according to (5), wherein the cured product when irradiated with UV light has a rolling distance of more than 150 mm as measured according to ASTM D 3121. [Effects of the Invention]

[0011] According to the present invention, there is provided a method for producing a curable composition which comprises a polyoxyalkylene polymer having a reactive silicon group, a (meth)acrylic polymer having a reactive silicon group, a hindered amine light stabilizer, and a hindered phenol antioxidant, and which can produce a cured product which is resistant to discoloration and surface tackiness in weathering tests. DETAILED DESCRIPTION OF THE INVENTION

[0012] The present invention will be described in detail below.

[0013] ≪Curable composition≫ The curable composition contains a polyoxyalkylene polymer (A) having a reactive silicon group, a (meth)acrylic polymer (B) having a reactive silicon group, a hindered amine light stabilizer (C), and a hindered phenol antioxidant (D). The (meth)acrylic polymer (B) contains a structural unit derived from a (meth)acrylic acid alkyl ester. The curable composition may optionally contain various other additives.

[0014] The curable composition is produced by a method including mixing a liquid resin component containing at least one of a polyoxyalkylene polymer (A) and a (meth)acrylic polymer (B) and having a temperature of 50°C or higher with a molten hindered phenol-based antioxidant (D).

[0015] Essential and optional components that the curable composition may contain are described below.

[0016] <Polyoxyalkylene polymer (A)> The polyoxyalkylene polymer (A) (hereinafter sometimes simply referred to as "polymer (A)") has a reactive silicon group at the end of the molecular chain. The reactive silicon group is not particularly limited as long as it can form a siloxane bond. Preferred examples of the reactive silicon group include those represented by the following formula (1): -SiR 1 3-a X a (1) (In formula (1), R 1 is a substituted or unsubstituted hydrocarbon group having 1 to 20 carbon atoms, or R 0 3SiO-, and three R 0 are hydrocarbon groups having 1 to 20 carbon atoms, which may be the same or different, X represents a hydroxyl group or a hydrolyzable group; a is 1, 2, or 3; R 1 , X, when there are multiple of them, they may be the same or different.) Examples of reactive silicon groups include those represented by the following formula: Polymer (A) has a polymer backbone and a polymer chain end bonded to the polymer backbone. In the specification and claims of this application, the polymer backbone is also referred to as the "main chain structure." The polymer backbone is a structure in which multiple structural units derived from monomers are bonded in succession. The monomer may be one type or multiple types.

[0017] The polymer chain end is a moiety located at the end of the polymer (A). The number of polymer chain ends of the polymer (A) is 2 when the main chain structure is linear, and 3 or more when the polymer backbone is branched. When the polymer (A) is a mixture of a polymer having a linear main chain structure and a polymer having a branched main chain structure, the number of polymer chain ends is an average value between 2 and 3.

[0018] The reactive silicon group may be present in the polymer backbone or at the polymer chain terminal. Furthermore, two or more reactive silicon groups may be present at the polymer chain terminal. When the curable composition is used as an adhesive, a sealant, an elastic coating agent, a pressure-sensitive adhesive, or the like, it is preferred that the reactive silicon group in the polymer (A) be present at the polymer chain terminal.

[0019] <Reactive silicon group> The reactive silicon group is a group that can generate a silanol group by hydrolysis. When the reactive silicon group generates a silanol group, the polymer (A) is crosslinked by a condensation reaction between the silanol groups. As mentioned above, the reactive silicon group is not particularly limited, but the reactive silicon group is preferably a group represented by the following formula (1): -SiR 1 3-a X a (1)

[0020] In formula (1), R 1 is a substituted or unsubstituted hydrocarbon group having 1 to 20 carbon atoms, or R 0 3SiO- represents a triorganosiloxy group. 0are hydrocarbon groups having 1 to 20 carbon atoms, and they may be the same or different. X represents a hydroxyl group or a hydrolyzable group. a is 1, 2, or 3. R 1 , X, when there are a plurality of them, they may be the same or different.

[0021] R in formula (1) 1 Specific examples of R include alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl, n-hexyl, 2-ethylhexyl, and n-dodecyl; unsaturated hydrocarbon groups such as vinyl, isopropenyl, and allyl; alkoxymethyl groups such as methoxymethyl; halogenated methyl groups such as chloromethyl; cycloalkyl groups such as cyclohexyl; aryl groups such as phenyl, toluyl, and 1-naphthyl; and aralkyl groups such as benzyl. Among these groups, alkyl and aryl groups are preferred, with methyl, ethyl, and phenyl groups being more preferred, methyl and ethyl groups being even more preferred, and methyl being particularly preferred. In formula (1), R 1 If there are multiple R 1 may be the same group or a combination of two or more different groups.

[0022] X in formula (1) is a hydroxyl group or a hydrolyzable group. The hydrolyzable group is not particularly limited and may be a known hydrolyzable group. Specific examples of the hydrolyzable group include a hydrogen atom, a halogen atom, 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, an alkoxy group, an acyloxy group, a ketoximate group, and an alkenyloxy group are preferred, and an alkoxy group such as a methoxy group and an ethoxy group is more preferred because of its mild hydrolysis and ease of handling. A methoxy group is preferred because it allows for easy adjustment of the curability of the curable composition.

[0023] The reactive silicon group represented by formula (1) is not particularly limited. Specific examples of the reactive silicon group represented by formula (1) include dimethoxymethylsilyl, diethoxymethylsilyl, trimethoxysilyl, triethoxysilyl, dimethoxyphenylsilyl, methoxymethyldimethoxysilyl, methoxymethyldiethoxysilyl, triisopropenyloxysilyl, and triacetoxysilyl. Among these, dimethoxymethylsilyl and trimethoxysilyl are preferred because they facilitate the synthesis of polymer (A). Trimethoxysilyl and methoxymethyldimethoxysilyl are preferred because they have excellent curability. Dimethoxymethylsilyl is particularly preferred because it has excellent stability.

[0024] (Main chain structure of polymer (A)) The polymer (A) is a polyoxyalkylene polymer. Therefore, the main chain structure of the polymer is made of a polyoxyalkylene polymer. Specific examples of the main chain structure of the polymer (A) include polyoxyalkylene polymers such as polyoxyethylene polymers, polyoxypropylene polymers, polyoxybutylene polymers, polyoxytetramethylene polymers, polyoxyethylene-polyoxypropylene copolymers, and polyoxypropylene-polyoxybutylene copolymers.

[0025] Among polyoxyalkylene polymers, polyoxypropylene is preferred as the main chain structure because it has excellent deep curing properties as a one-component composition due to its high moisture permeability and also has excellent adhesive properties.

[0026] The polyoxyalkylene polymer is -R 3 It is a polymer having a repeating unit represented by -O-. 3 R is a linear or branched alkylene group having 1 to 14 carbon atoms. 3 As —R, a linear or branched alkylene group having 2 to 4 carbon atoms is more preferred. 3Specific examples of the repeating unit represented by -O- include -CHO-, -CHCHO-, -CHCH(CH)O-, -CHCH(CH)O-, -CHC(CH)(CH)O-, and -CHCHCHCHO-. The main chain structure of the polyoxyalkylene polymer may consist of only one type of repeating unit, or may consist of two or more types of repeating units. In particular, when the curable composition is used as a sealant, adhesive, or the like, a polyoxypropylene polymer having oxypropylene repeating units in an amount of 50% by weight or more, preferably 80% by weight or more, of the polymer main chain structure is preferred as the polyoxyalkylene polymer. This is because such polyoxyalkylene polymers are amorphous and have relatively low viscosity.

[0027] The main chain structure of the polyoxyalkylene polymer may be linear or branched.

[0028] The polyoxyalkylene polymer is preferably a polymer obtained by ring-opening polymerization of a cyclic ether compound in the presence of an initiator using a polymerization catalyst.

[0029] Examples of the cyclic ether compound include ethylene oxide, propylene oxide, butylene oxide, tetramethylene oxide, tetrahydrofuran, etc. These cyclic ether compounds may be used alone or in combination of two or more. Among these cyclic ether compounds, propylene oxide is particularly preferred because it can give an amorphous polyether polymer having a relatively low viscosity.

[0030] Specific examples of the initiator 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 polyoxyalkylene polymers such as polyoxypropylene diol, polyoxypropylene triol, polyoxyethylene diol, and polyoxyethylene triol.

[0031] The method for synthesizing the polyoxyalkylene polymer is not particularly limited. Examples of methods for synthesizing polyoxyalkylene polymers include a polymerization method using an alkali catalyst such as KOH; a polymerization method using a transition metal compound-porphyrin complex catalyst, such as the complex obtained by reacting an organoaluminum compound with porphyrin, as disclosed in JP-A-61-215623; a polymerization method using a composite metal cyanide complex catalyst, as disclosed in JP-B-46-27250, JP-B-59-15336, U.S. Pat. Nos. 3,278,457, 3,278,458, 3,278,459, 3,427,256, 3,427,334, and 3,427,335; a polymerization method using a catalyst made of a polyphosphazene salt, as exemplified in JP-A-10-273512; and a polymerization method using a catalyst made of a phosphazene compound, as exemplified in JP-A-11-060722. The polymerization method using a double metal cyanide complex catalyst is more preferred because it has low production costs and can produce a polymer with a narrow molecular weight distribution.

[0032] The main chain structure of the polymer (A) may be a polyoxyalkylene polymer containing bonds other than ether bonds, such as urethane bonds and urea bonds, within the range that does not significantly impair the desired effects. Specific examples of polymers having such a main chain structure include polyurethane prepolymers and polyurea prepolymers.

[0033] The polyurethane prepolymer can be obtained by a known method such as a method of reacting a polyol compound with a polyisocyanate compound, and the polyurea prepolymer can be obtained by a known method such as a method of reacting a polyamine compound with a polyisocyanate compound. The main chain structure may be a prepolymer having a combination of urethane bonds and urea bonds, which is obtained by reacting a polyol compound and a polyamine compound with a polyisocyanate compound.

[0034] Specific examples of the polyol compound include polyether polyol, polyester polyol, polycarbonate polyol, and polyether polyester polyol.

[0035] Specific examples of polyisocyanate compounds include diphenylmethane diisocyanate, tolylene diisocyanate, xylylene diisocyanate, methylene-bis(cyclohexyl isocyanate), isophorone diisocyanate, and hexamethylene diisocyanate.

[0036] The polyurethane prepolymer may have a terminal group of either a hydroxyl group or an isocyanate group, and the polyurea prepolymer may have a terminal group of either an amino group or an isocyanate group.

[0037] In a cured product of a curable composition containing, as the polymer (A), a polymer having one or more bonds selected from a urethane bond, a urea bond, and an ester bond in the main chain structure, the strength of the cured product may decrease due to cleavage of the urethane bond, urea bond, or ester bond in the main chain structure due to heat or the like.

[0038] When a polymer containing an amide bond in the main chain structure is used as the organic polymer, the curability of the curable composition may be improved. 4 It is represented by -C(=O)-. 4is a hydrogen atom or an organic group which may have a substituent. When the amount of amide bonds in the main chain structure is within an appropriate range, the viscosity of the polymer is low, and a decrease in strength of the cured product due to cleavage of the amide bonds due to heat or the like and an increase in viscosity of the curable composition due to storage are unlikely to occur, and the workability of the curable composition is good.

[0039] When the polymer (A) contains an amide bond in its main chain structure, the average number of amide bonds per molecule is preferably 1 to 10, more preferably 1.5 to 5, and even more preferably 2 to 3. When the average number of amide bonds per molecule is within this range, the curable composition has good curability, the viscosity of the polymer (A) is low, and the polymer (A) and the curable composition are easy to handle.

[0040] As the polymer (A) described above, a polyoxyalkylene polymer that does not contain a urethane bond, a urea bond, an ester bond, or an amide bond in the main chain structure is most preferred, from the viewpoint of obtaining a curable composition excellent in storage stability and workability.

[0041] The polymer (A) is preferably a polymer obtained by introducing a reactive silicon group into a polymer by any of the following methods (a) to (d). (a) After converting the terminal hydroxyl groups of the hydroxyl-terminated organic polymer into carbon-carbon unsaturated groups, the carbon-carbon unsaturated groups are converted into HSiR 1 3-a X a A method of hydrosilylation using a hydrosilane represented by the formula R 1 , X, and a are the same as those in general formula (1). (b) OCN-W-SiR 1 3-a X a A method of reacting an isocyanate alkylsilane compound represented by the formula: W is a divalent organic group. 1 , X, and a are the same as those in general formula (1). (c) After converting the terminal hydroxyl groups of the hydroxyl-terminated organic polymer to carbon-carbon unsaturated groups, the carbon-carbon unsaturated groups and HS-W-SiR1 3-a X a A method of carrying out an ene-thiol reaction with a mercaptoalkylsilane compound represented by the formula: W is a divalent organic group. 1 , X, and a are the same as those in general formula (1). (d) A hydroxyl-terminated organic polymer is reacted with a polyisocyanate compound to synthesize an NCO-terminated organic polymer, and then the terminal NCO groups are converted into an NCO-terminated organic polymer by the reaction of HNR 5 -W-SiR 1 3-a X a , or HS-W-SiR 1 3-a X a A method of reacting a silane compound represented by the formula: W is a divalent organic group. 5 is a hydrogen atom or an alkyl group. 1 , X, and a are the same as those in general formula (1).

[0042] In the above methods (a) and (c), examples of the terminal carbon-carbon unsaturated group include a vinyl group, an allyl group, a methallyl group, an allenyl group, and a propargyl group.

[0043] In any of the above methods (b) to (d), the polymer (A) obtained by using a silane compound in which W is methylene exhibits very high curability.

[0044] Method (a) is preferred because it is easy to obtain a polymer (A) having good storage stability, while methods (b), (c), and (d) are preferred because they can achieve a high conversion rate in a relatively short reaction time.

[0045] The method for introducing a reactive silicon group by method (a) has been proposed in Japanese Patent Publication Nos. 45-36319, 46-12154, Japanese Patent Laid-Open Nos. 50-156599, 54-6096, 55-13767, 55-13468, 57-164123, Japanese Patent Publication No. 3-2450, U.S. Pat. Nos. 3,632,557, 4,345,053, 4,366,307, and 4,960,844. Examples of such methods include the method proposed in Japanese Patent Laid-Open Nos. 61-197631, 61-215622, 61-215623, and 61-218632, in which reactive silicon groups are introduced by hydrosilylation or the like into a high-molecular-weight, narrow-molecular-weight distribution polyoxypropylene polymer having a number-average molecular weight of 6,000 or more and an Mw / Mn ratio of 1.6 or less, as well as the method proposed in Japanese Patent Laid-Open No. 3-72527. Furthermore, a method for introducing more than one reactive silicon group into a molecular terminal is proposed in Japanese Patent No. 6,096,320.

[0046] The number average molecular weight of the polymer (A) is not particularly limited. The number average molecular weight of the polymer (A), as polystyrene-equivalent molecular weight measured by GPC, is preferably 3,000 to 100,000, more preferably 3,000 to 50,000, and particularly preferably 3,000 to 30,000. When the number average molecular weight is within the above range, the amount of reactive silicon groups introduced is appropriate, making it easy to obtain a polymer (A) that has a viscosity that is easy to handle and excellent workability, while keeping production costs within an appropriate range.

[0047] The molecular weight of polymer (A) can also be expressed as an end-group-converted molecular weight calculated by directly measuring the end-group concentration of a polymer precursor before the introduction of reactive silicon groups using titration analysis based on the principles of the hydroxyl value measurement method specified in JIS K 1557 and the iodine value measurement method specified in JIS K 0070, and taking into account the polymer structure (the degree of branching determined by the polymerization initiator used).The end-group-converted molecular weight of polymer (A) can also be calculated by creating a calibration curve of the number average molecular weight determined by general GPC measurement of the polymer precursor and the end-group-converted molecular weight, and converting the number average molecular weight determined by GPC of polymer (A) into an end-group-converted molecular weight.

[0048] The molecular weight distribution (Mw / Mn) of the polymer (A) is not particularly limited. It is preferable that the molecular weight distribution of the polymer (A) is narrow. Specifically, the molecular weight distribution is preferably 1.6 or less, more preferably 1.4 or less, even more preferably 1.3 or less, and particularly preferably 1.2 or less. The molecular weight distribution of the polymer (A) can be determined from the number average molecular weight and weight average molecular weight obtained by GPC measurement.

[0049] To obtain a good rubber-like cured product, the reactive silicon groups of the polymer (A) are preferably present at the polymer chain terminals. The number of reactive silicon groups per polymer chain terminal is preferably 0.5 or more and 3.0 or less on average, more preferably 0.6 or more and 2.5 or less, even more preferably 0.7 or more and 2.2 or less, and particularly preferably 0.8 or more and 2.0 or less. When the number of reactive silicon groups is 0.5 or more, the curability of the polymer (A) and the curable composition is good, and the cured product of the curable composition has good rubber elasticity.

[0050] The number of reactive silicon groups in one molecule is preferably 1 to 7 on average, more preferably 1 to 4, and particularly preferably 1 to 3.

[0051] Furthermore, as described in WO2013 / 180203, an organic polymer having two or more reactive silicon groups at the polymer chain terminals can also be used as the polymer (A). Such a polymer (A) exhibits high curability, and the resulting cured product can be expected to have high strength and high recovery.

[0052] Specific examples of commercially available polymer (A) products include various reactive silicon group-containing polyoxypropylene products such as Kaneka MS Polymer (registered trademark) and Kaneka Silyl (registered trademark). All of these commercially available polymers (A) are products of Kaneka Corporation. Other usable products include EXCESTAR (registered trademark) from AGC Corporation, GENIOSIL (registered trademark) from WACKER, and STP from RISUN POLYMER.

[0053] <(Meth)acrylic polymer (B)> The (meth)acrylic polymer (B) (hereinafter sometimes simply referred to as "polymer (B)") has a reactive silicon group at the end of the molecular chain. The reactive silicon group is not particularly limited as long as it can form a siloxane bond. The reactive silicon group is preferably a reactive silicon group represented by the above formula (1). The polymer (B) has a polymer backbone and a polymer chain end bonded to the polymer backbone. The polymer backbone is a structure in which multiple structural units derived from monomers are bonded in succession. The monomer may be one type or multiple types.

[0054] The polymer chain end is a moiety located at the end of the polymer (B). The number of polymer chain ends of the polymer (B) is 2 when the main chain structure is linear, and 3 or more when the polymer backbone is branched. When the polymer (B) is a mixture of a polymer having a linear main chain structure and a polymer having a branched main chain structure, the number of polymer chain ends is an average value between 2 and 3.

[0055] The reactive silicon group may be present in the polymer backbone or at the polymer chain terminal. Furthermore, two or more reactive silicon groups may be present at the polymer chain terminal. When the curable composition is used as an adhesive, a sealant, an elastic coating agent, a pressure-sensitive adhesive, or the like, it is preferred that the reactive silicon group in the polymer (B) be present at the polymer chain terminal.

[0056] The reactive silicon group in the polymer (B) may be the same as or different from the reactive silicon group in the polymer (A).

[0057] (Main chain structure of polymer (B)) The polymer (B) contains a structural unit derived from a (meth)acrylic acid alkyl ester. The polymer (B) may contain structural units derived from two or more types of (meth)acrylic acid alkyl esters. The (meth)acrylic acid alkyl ester means an acrylic acid alkyl ester and / or a methacrylic acid alkyl ester. Specific examples of acrylic acid alkyl esters include methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, isobutyl acrylate, tert-butyl acrylate, n-hexyl acrylate, 2-ethylhexyl acrylate, n-decyl acrylate, n-undecyl acrylate, lauryl acrylate, n-tridecyl acrylate, myristyl acrylate, cetyl acrylate, stearyl acrylate, and behenyl acrylate.

[0058] Specific examples of methacrylic acid alkyl esters include methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, tert-butyl methacrylate, n-hexyl methacrylate, 2-ethylhexyl methacrylate, n-decyl methacrylate, n-undecyl methacrylate, lauryl methacrylate, n-tridecyl methacrylate, myristyl methacrylate, cetyl methacrylate, stearyl methacrylate, and behenyl methacrylate.

[0059] The ratio of the weight of the structural units derived from a (meth)acrylic acid alkyl ester to the weight of the polymer (B) is preferably 50% by weight or more, and more preferably 70% by weight or more.

[0060] In terms of the compatibility of polymer (B) with polymer (A) and the like and the stability of polymer (B), the monomer for preparing polymer (B) is preferably a (meth)acrylic acid alkyl ester having an alkyl group having 1 to 30 carbon atoms.

[0061] The (meth)acrylic acid alkyl ester having an alkyl group having 1 to 30 carbon atoms is represented by the following formula (B1): CH2=CR b1 COOR b2 (B1) (In formula (B1), R b1 is a hydrogen atom or a methyl group. b2 is an alkyl group having 1 to 30 carbon atoms. It is expressed as:

[0062] In formula (B1), R b2 Examples of the alkyl group include alkyl groups having 1 to 30 carbon atoms, such as a methyl group, an ethyl group, an n-propyl group, an n-butyl group, a tert-butyl group, a 2-ethylhexyl group, a lauryl group, an n-tridecyl group, a cetyl group, and a stearyl group. R b2 The alkyl group as the group preferably has 1 to 20 carbon atoms.

[0063] The monomers for producing the polymer (B) may contain other monomers in addition to the alkyl (meth)acrylate ester. Other monomers include acrylic acid and methacrylic acid; (meth)acrylamides such as acrylamide, methacrylamide, N-methylolacrylamide, and N-methylolmethacrylamide; epoxy group-containing (meth)acrylic acid esters such as glycidyl acrylate and glycidyl methacrylate; amino group-containing unsaturated compounds such as 2-(N,N-diethylamino)ethyl methacrylate and 2-aminoethyl vinyl ether; acrylonitrile and methacrylonitrile; styrenes such as styrene and α-methylstyrene; alkyl vinyl ethers; vinyl chloride; and fatty acid vinyl esters such as vinyl acetate and vinyl propionate.

[0064] The molecular weight of the polymer (B) is not particularly limited as long as the desired effects are not impaired. The molecular weight of the (meth)acrylic copolymer (B) is preferably 500 to 100,000, more preferably 1,000 to 10,000, in terms of polystyrene equivalent number average molecular weight measured by GPC. The molecular weight distribution (Mw / Mn) of the polymer (B) is not particularly limited. It is preferable that the molecular weight distribution of the polymer (B) is narrow. Specifically, the molecular weight distribution is preferably 1.6 or less, more preferably 1.4 or less, even more preferably 1.3 or less, and particularly preferably 1.2 or less. The molecular weight distribution of the polymer (B) can be determined from the number average molecular weight and weight average molecular weight obtained by GPC measurement.

[0065] The polymer (B) can be produced by a conventional vinyl polymerization method. Examples of the vinyl polymerization method include a solution polymerization method using a radical reaction and a bulk polymerization method. The vinyl polymerization method is not limited to these methods. The above polymerization reaction is typically carried out at 50 to 150° C. in the presence of monomers, a radical initiator, a chain transfer agent, a solvent, and the like. The polymerization reaction conditions are not limited to the above conditions.

[0066] Specific examples of the radical initiator include azobisisobutyronitrile, 2,2'-azobis(2-methylbutyronitrile), and benzoyl peroxide. Specific examples of the chain transfer agent include mercaptans such as n-dodecyl mercaptan, tert-dodecyl mercaptan, and lauryl mercaptan, and halogen-containing compounds. As the solvent, for example, solvents inert to the polymerization reaction, such as ethers, hydrocarbons, and esters, can be preferably used.

[0067] Various methods are known for introducing reactive silicon groups into (meth)acrylic polymers. Specific examples include: I) A method of copolymerizing a compound having an ethylenically unsaturated double bond and a reactive silicon group with a (meth)acrylic acid alkyl ester represented by formula (B1); II) A method in which a compound having an ethylenically unsaturated double bond and a reactive functional group (e.g., acrylic acid) is copolymerized with a (meth)acrylic acid alkyl ester represented by formula (B1), and the reactive functional group in the copolymer is reacted with reactive silicon and a compound capable of reacting with the reactive group (e.g., a reactive silicon group-containing isocyanate compound); III) A method of polymerizing a (meth)acrylic acid alkyl ester represented by formula (B1) in the presence of a mercaptan having a reactive silicon group as a chain transfer agent; VI) A method of polymerizing a (meth)acrylic acid alkyl ester represented by formula (B1) using an azobisnitrile compound having a reactive silicon group or a disulfide compound having a reactive silicon group as an initiator; and V) A method of introducing a reactive silicon group into the molecular chain terminal of a polymer obtained by polymerizing an alkyl (meth)acrylate ester represented by formula (B1) by living radical polymerization can be mentioned. The method for introducing a reactive silicon group into a (meth)acrylic polymer is not limited to the above-mentioned method.

[0068] The compound having an ethylenically unsaturated double bond and a reactive silicon group used in the above method I) includes compounds represented by the following formula (B2): CH2=CR b5 COOR b6 -SiR 1 3-a X a (B2) (In formula (B2), R 1 , X, and a are R in formula (1). 1 , X, and a. R b5 is a hydrogen atom or a methyl group. b6 is an alkylene group having 1 to 6 carbon atoms. A compound represented by the following formula is preferred.

[0069] In formula (B2), R b6 The alkylene group as is an alkylene group having 1 to 6 carbon atoms such as a methylene group, an ethane-1,2-diyl group (ethylene group), and a propane-1,3-diyl group (trimethylene group), and is preferably an alkylene group having 1 to 4 carbon atoms.

[0070] Specific examples of compounds having an ethylenically unsaturated double bond and a reactive silicon group include γ-methacryloxypropylalkoxysilanes such as γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropylmethyldimethoxysilane, and γ-methacryloxypropyltriethoxysilane; γ-acryloxypropylalkoxysilanes such as γ-acryloxypropyltrimethoxysilane, γ-acryloxypropylmethyldimethoxysilane, and γ-acryloxypropyltriethoxysilane; and vinylalkoxysilanes such as vinyltrimethoxysilane, vinylmethyldimethoxysilane, and vinyltriethoxysilane.

[0071] In the compound having an ethylenically unsaturated double bond and a reactive functional group used in the above method II), examples of the reactive functional group include an amino group, a hydroxyl group, and a carboxyl group. Examples of groups that can react with these reactive functional groups include an isocyanate group. Other examples include allyl groups as reactive functional groups, as described in JP-A-54-36395, JP-A-01-272654, and JP-A-02-214759, etc. Examples of groups that can react with allyl groups include silicon hydride groups (H—Si).

[0072] Examples of mercaptans containing a reactive silicon group that can be used as chain transfer agents in the above method III) include γ-mercaptopropyltrimethoxysilane, γ-mercaptopropylmethyldimethoxysilane, and γ-mercaptopropyltriethoxysilane.

[0073] Examples of the azobisnitrile compound having a reactive silicon group and the disulfide compound used in the above method IV) include the azobisnitrile compound having an alkoxysilyl group and the disulfide compound having an alkoxysilyl group described in JP-A-60-23405 and JP-A-62-70405.

[0074] The above method V) includes the method described in JP-A-09-272714.

[0075] Other methods include those described in JP-A Nos. 59-168014 and 60-228516, which use a mercaptan having a reactive silicon group in combination with a radical polymerization initiator having a reactive silicon group.

[0076] The number of reactive silicon groups contained in the polymer (B) is not particularly limited, and the average number of reactive silicon groups contained in the polymer (B) is preferably 0.1 to 2.0, more preferably 0.5 to 1.5, per molecule.

[0077] The amount of the polymer (B) used in the curable composition is not particularly limited as long as the desired effects are not impaired. In the curable composition, the weight W of the (meth)acrylic polymer (B) B The weight W of the polyoxyalkylene polymer (A) relative to A Ratio of W A / W B The ratio is preferably 20 / 80 to 80 / 20, and may be 30 / 70 to 70 / 30.

[0078] It is common knowledge among those skilled in the art that the monomer composition of the polymer (B) is selected depending on the use and purpose of the curable composition. When the curable composition is used for applications requiring strength, such as adhesives, it is preferable that the polymer (B) has a relatively high glass transition temperature (Tg). Specifically, the Tg of the (meth)acrylic acid ester polymer (B) is preferably 0 to 200°C, and more preferably 20 to 100°C. Tg can be calculated using the following Fox formula.

[0079] Fox's formula: 1 / (Tg(K))=Σ(Mi / Tgi) (In the formula, Mi is the weight fraction of the monomer i component constituting the polymer, and Tgi is the glass transition temperature (K) of the homopolymer of monomer i.)

[0080] For example, polymethyl methacrylate is known as a (meth)acrylic polymer with a relatively high glass transition temperature (Tg). Therefore, in the monomers used to produce polymer (B), the higher the weight ratio of methyl methacrylate to the weight of the monomer, the higher the glass transition temperature (Tg) of polymer (B) tends to be. Conversely, the lower the weight ratio of methyl methacrylate to the weight of the monomer, the lower the glass transition temperature (Tg) of polymer (B) tends to be. When the curable composition is used as an adhesive, it is preferable that the weight ratio of methyl methacrylate to the weight of the monomers used in producing the polymer (B) is 50% or more, as this makes it easier to form a high-strength cured product. When the curable composition is used as a sealant, it is preferable that the ratio by weight of methyl methacrylate to the weight of the monomers used in producing the polymer (B) is less than 50%, since this results in a low viscosity of the curable composition and good workability.

[0081] <Hindered amine light stabilizer (C)> The curable composition contains a hindered amine light stabilizer (C). Use of the hindered amine light stabilizer (C) inhibits photooxidative deterioration of the cured product, thereby improving the weather resistance of the cured product. The amount of the hindered amine light stabilizer (C) used is preferably 0.1 to 10 parts by weight, more preferably 0.2 to 7 parts by weight, per 100 parts by weight of the total of the weight of the polymer (A) and the weight of the polymer (B).

[0082] The type of the hindered amine light stabilizer (C) is not particularly limited as long as the desired effect is not impaired. Suitable hindered amine light stabilizers (C) include tertiary amine-containing hindered amine light stabilizers. Tertiary amine-containing hindered amine light stabilizers include TINUVIN 123, TINUVIN 144, TINUVIN 249, TINUVIN 292, TINUVIN 312, TINUVIN 622LD, TINUVIN 765, TINUVIN 770, TINUVIN 880, TINUVIN 5866, TINUVIN B97, CHIMASSORB119FL, and CHIMASSORB944LD (all manufactured by BASF); ADK STAB LA-57, LA-62, LA-63P, LA-67, and LA-68 (all manufactured by ADEKA Corporation); SANOL LS-292, LS-2626, LS-765, LS-744, and LS-1114 (all manufactured by Sankyo Lifetech Co., Ltd.), SABOSTAB UV91, SABOSTAB UV119, SONGSORB CS5100, SONGSORB CS622, and SONGSORB Examples include CS944 (all manufactured by SONGWON) and Nocrac CD (manufactured by Ouchi Shinko Chemical Industry Co., Ltd.). The hindered amine light stabilizer (C) may be used alone or in combination of two or more kinds.

[0083] The molecular weight of the hindered amine light stabilizer (C) is preferably from 300 to 3,000, and more preferably from 400 to 2,500 from the viewpoint of solubility in the resin component. The melting point of the hindered amine light stabilizer (C) is preferably from 0 to 200°C, more preferably from 50 to 150°C, in order to provide a good usability of the curable composition.

[0084] <Hindered phenol antioxidant (D)> The curable composition contains a hindered phenol-based antioxidant (D). The use of the hindered phenol-based antioxidant (D) enhances the weather resistance of the cured product. The type of hindered phenol antioxidant (D) is not particularly limited as long as the desired effect is not impaired. Examples of the hindered phenol antioxidant (D) include Irganox 245, Irganox 1010, Irganox 1035, Irganox 1076, Irganox 1135, Irganox 1330, and Irganox 1520 (all manufactured by BASF); SONGNOX 1076 (manufactured by SONGWON); and BHT. The hindered phenol-based antioxidant (D) may be used alone or in combination of two or more kinds.

[0085] The amount of antioxidant used is preferably 0.1 to 10 parts by weight, more preferably 0.15 to 5 parts by weight, per 100 parts by weight of the total of the weight of the polymer (A) and the weight of the (meth)acrylic polymer (B).

[0086] The molecular weight of the hindered phenol-based antioxidant (D) is preferably from 300 to 1,500, and more preferably from 400 to 1,000 from the viewpoint of solubility in the resin component. The melting point of the hindered phenol-based antioxidant (D) is preferably from 0°C to 200°C, more preferably from 50 to 150°C, in order to provide a good usability for the curable composition.

[0087] In the curable composition, the number of moles N of hydroxy groups contained in the hindered phenol-based antioxidant (D) is OH The number of moles N of nitrogen atoms contained in the hindered amine light stabilizer (C) relative to N Ratio of N N / N OH is preferably 0.1 to 10. In the curable composition, the number of moles N of the hindered phenol-based antioxidant (D) D The number of moles N of the hindered amine light stabilizer (C) relative to C Ratio of N C / N D However, it is preferably 20 / 80 to 80 / 20, and may be 30 / 70 to 70 / 30.

[0088] <Other additives> The curable composition may contain additives other than the polymer (A), the polymer (B), the hindered amine light stabilizer (C), and the hindered phenolic antioxidant (D), provided that the desired effects are not impaired. Examples of such additives include curing catalysts, fillers, adhesion promoters, plasticizers, solvents, diluents, thixotropy-imparting agents, antioxidants, light stabilizers, UV absorbers, physical property modifiers, tackifying resins, epoxy group-containing compounds, photocurable substances, oxygen-curable substances, epoxy resins, other resins, surface property modifiers, foaming agents, curability modifiers, flame retardants, silicates, radical inhibitors, metal deactivators, phosphorus-based peroxide decomposers, lubricants, pigments, and mildew inhibitors.

[0089] (curing catalyst) The curable composition may contain a silanol condensation catalyst as a curing catalyst for the purpose of promoting a hydrolysis condensation reaction between the reactive silicon groups of the polymer (A) and the polymer (B) and chain-extending or crosslinking the polymer. Examples of the silanol condensation catalyst include organotin compounds, metal carboxylates, amine compounds, carboxylic acids, and alkoxy metals.

[0090] Specific examples of organotin compounds include dibutyltin dilaurate, dibutyltin dioctanoate, dibutyltin bis(butyl maleate), dibutyltin diacetate, dibutyltin oxide, dibutyltin diacetylacetonate, dioctyltin diacetylacetonate, dioctyltin dilaurate, dioctyltin distearate, dioctyltin diacetate, dioctyltin oxide, a reaction product of dibutyltin oxide with a silicate compound, a reaction product of dioctyltin oxide with a silicate compound, and a reaction product of dibutyltin oxide with a phthalate ester.

[0091] Specific examples of the metal carboxylate include tin carboxylate, bismuth carboxylate, titanium carboxylate, zirconium carboxylate, iron carboxylate, etc. Furthermore, as the metal carboxylate, salts of the following carboxylic acids combined with various metals can be used.

[0092] Specific examples of the amine compound include amines such as octylamine, 2-ethylhexylamine, laurylamine, and stearylamine; nitrogen-containing heterocyclic compounds such as pyridine, 1,8-diazabicyclo[5,4,0]undecene-7 (DBU), and 1,5-diazabicyclo[4,3,0]nonene-5 (DBN); guanidines such as guanidine, phenylguanidine, and diphenylguanidine; biguanides such as butylbiguanide, 1-o-tolylbiguanide, and 1-phenylbiguanide; amino group-containing silane coupling agents; and ketimine compounds.

[0093] 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.

[0094] Specific examples of alkoxy metals include titanium compounds such as tetrabutyl titanate, titanium tetrakis(acetylacetonate), and diisopropoxytitanium bis(ethylacetoacetate); aluminum compounds such as aluminum tris(acetylacetonate) and diisopropoxyaluminum ethylacetoacetate; and zirconium compounds such as zirconium tetrakis(acetylacetonate). Other silanol condensation catalysts that can be used include fluorine anion-containing compounds, photoacid generators, and photobase generators. Two or more different silanol condensation catalysts may be used in combination. The amount of the silanol condensation catalyst used is preferably 0.001 to 20 parts by weight, more preferably 0.01 to 15 parts by weight, and particularly preferably 0.01 to 10 parts by weight, per 100 parts by weight of the total of the weight of the polyoxyalkylene polymer (A) and the weight of the (meth)acrylic polymer (B).

[0095] (filler) The curable composition may contain various fillers, such as reinforcing fillers such as fumed silica, precipitated silica, crystalline silica, fused silica, dolomite, anhydrous silicic acid, hydrous silicic acid, and carbon black; heavy calcium carbonate, colloidal calcium carbonate, magnesium carbonate, diatomaceous earth, calcined clay, clay, talc, titanium oxide, bentonite, organic bentonite, ferric oxide, fine aluminum powder, flint powder, zinc oxide, activated zinc oxide, and resin powder; and fibrous fillers such as asbestos, glass fiber, and filament. Examples of resin powder include PVC powder and PMMA powder. When a filler is used, the amount of the filler used is preferably 1 to 300 parts by weight, more preferably 10 to 200 parts by weight, per 100 parts by weight of the total of the weight of the polyoxyalkylene polymer (A) and the weight of the (meth)acrylic polymer (B).

[0096] When it is desired to obtain a cured product having high strength by using these fillers, fillers selected from the group consisting of fumed silica, precipitated silica, crystalline silica, fused silica, dolomite, silicic acid anhydride, hydrated silicic acid, carbon black, surface-treated fine calcium carbonate, calcined clay, clay, and activated zinc oxide are preferably used. The amount of these fillers used, which is preferable in terms of the strength of the cured product, is preferably 1 to 200 parts by weight per 100 parts by weight of the total weight of the polyoxyalkylene polymer (A) and the (meth)acrylic polymer (B). Furthermore, when a cured product with low strength and high elongation at break is desired, fillers selected from titanium oxide, calcium carbonate, magnesium carbonate, talc, ferric oxide, zinc oxide, shirasuballoon, and the like can be preferably used. The amount of these fillers used, which is preferable in terms of the elongation at break of the cured product, is preferably 5 to 200 parts by weight per 100 parts by weight of the total weight of the polyoxyalkylene polymer (A) and the (meth)acrylic polymer (B).

[0097] Generally, the larger the specific surface area of ​​calcium carbonate, the greater the effect of improving the breaking strength, breaking elongation, and adhesiveness of the cured product. These fillers can be used alone or in combination with two or more types. Fatty acid surface-treated colloidal calcium carbonate can be used in combination with calcium carbonate with a particle size of 1 μm or more, such as untreated ground calcium carbonate.

[0098] The curable composition may contain spherical hollow bodies such as balloons for the purpose of reducing the weight (specific gravity) of the cured product. Balloons are hollow spherical fillers. Examples of balloon materials include inorganic materials such as glass, shirasu, and silica, and organic materials such as phenolic resin, urea resin, polystyrene, saran, and acrylonitrile. The balloon material is not limited to these materials. The balloon material may also be a composite material composed of an inorganic material and an organic material. The balloon material may also be a laminate of multiple layers. One type of balloon may be used alone, or two or more types may be used in combination. The surface of the balloon may be surface-treated, coated, or treated with various surface treatment agents. For example, organic balloons coated with calcium carbonate, talc, titanium oxide, etc., or inorganic balloons surface-treated with a silane coupling agent may be used.

[0099] The particle size of the balloons is preferably 3 μm to 200 μm, and particularly preferably 10 μm to 110 μm. When the particle size of the balloons is within this range, the use of an appropriate amount of balloons can reduce the weight of the cured product to a desired extent, and a cured product can be formed while suppressing the occurrence of surface irregularities and a decrease in elongation.

[0100] When balloons are used, an anti-slip agent such as that described in JP-A-2000-154368 or an amine compound for imparting a matte finish to the surface of the cured product by providing a roughened surface such as that described in JP-A-2001-164237 can be added to the curable composition. As the amine compound, primary and / or secondary amines with a melting point of 35° C. or higher are particularly preferred.

[0101] Specific examples of balloons are described in JP-A Nos. 2-129262, 4-8788, 4-173867, 5-1225, 7-113073, 9-53063, 10-251618, 2000-154368, 2001-164237, WO97 / 05201, and the like.

[0102] The amount of spherical hollow bodies (balloons) used is preferably 0.01 to 30 parts by weight per 100 parts by weight of the total of the weight of the polyoxyalkylene polymer (A) and the weight of the (meth)acrylic polymer (B). The lower limit is more preferably 0.1 part by weight, and the upper limit is more preferably 20 parts by weight. When the amount of spherical hollow bodies is within the above range, the curable composition has good properties and a cured product having excellent elongation and breaking strength is easily formed.

[0103] (adhesion imparting agent) The curable composition may contain an adhesion promoter, such as a silane coupling agent. A silane coupling agent is a compound having a hydrolyzable silicon group and a functional group other than the hydrolyzable silicon group in the molecule. When the curable composition is applied to various adherends, such as inorganic substrates such as glass, aluminum, stainless steel, zinc, copper, and mortar, or organic substrates such as vinyl chloride, acrylic, polyester, polyethylene, polypropylene, and polycarbonate, the use of a silane coupling agent exhibits a significant adhesive improvement effect under non-primer conditions or primer-treated conditions. When the curable composition is used under non-primer conditions, the effect of improving adhesion to various adherends is particularly significant. In addition to the above functions, the silane coupling agent can also function as a dehydrating agent, a physical property adjuster, a dispersibility improver for inorganic fillers, etc.

[0104] The hydrolyzable group in the hydrolyzable silicon group contained in the silane coupling agent is not particularly limited. Examples of hydrolyzable groups include hydrogen atoms, halogen atoms, alkoxy groups, aryloxy groups, alkenyloxy groups, acyloxy groups, ketoximate groups, amino groups, amide groups, acid amide groups, aminooxy groups, and mercapto groups. Among these, halogen atoms, alkoxy groups, alkenyloxy groups, and aryloxy groups are preferred due to their high activity. Chlorine atoms and alkoxy groups are preferred because they are easily introduced into the silane coupling agent. Alkoxy groups such as methoxy groups and ethoxy groups are more preferred because of their mild hydrolysis and ease of handling, with methoxy groups and ethoxy groups being particularly preferred. Furthermore, ethoxy groups and isopropenyloxy groups are preferred from the standpoint of safety, as the compounds that are eliminated by reaction are ethanol and acetone, respectively. The number of hydrolyzable groups bonded to the silicon atom in the silane coupling agent may be preferably three to ensure good adhesion. Furthermore, two may be preferable to ensure the storage stability of the curable composition.

[0105] When a silane coupling agent is used as an adhesion promoter, an aminosilane coupling agent having a hydrolyzable silicon group and a substituted or unsubstituted amino group is preferred because it has a significant effect of improving adhesion. The substituent in the substituted amino group is not particularly limited. Examples of the substituent include an alkyl group, an aralkyl group, and an aryl group.

[0106] Specific examples of aminosilane coupling agents include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropyltriisopropoxysilane, 3-aminopropylmethyldimethoxysilane, 3-aminopropylmethyldiethoxysilane, 3-(2-aminoethylamino)propyltrimethoxysilane, 3-(2-aminoethylamino)propylmethyldimethoxysilane, 3-(2-aminoethylamino)propyltriethoxysilane, 3-(2-aminoethylamino)propylmethyldiethoxysilane, 3-(2-aminoethylamino)propyltriisopropoxysilane, 3-(2-(2-aminoethylamino)ethylamino)propyltrimethoxysilane, 3-(6-aminohexylamino)propyltrimethoxysilane, and 3-ethylamino-2-methylpropyltrimethoxysilane. amino group-containing silanes such as methyl silane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, 3-phenylaminopropyltrimethoxysilane, 3-benzylaminopropyltrimethoxysilane, 3-(vinylbenzylamino)propyltriethoxysilane, N-cyclohexylaminomethyltriethoxysilane, N-cyclohexylaminomethyldiethoxymethylsilane, N-phenylaminomethyltrimethoxysilane, N-butylaminopropyltrimethoxysilane, (2-aminoethylamino)methyltrimethoxysilane, N,N'-bis[3-(trimethoxysilyl)propyl]ethylenediamine, and bis(trimethoxysilylpropyl)amine; and ketimine-type silanes such as N-(1,3-dimethylbutylidene)-3-(triethoxysilyl)-1-propanamine.

[0107] Among these, 3-aminopropyltrimethoxysilane, 3-(2-aminoethylamino)propyltrimethoxysilane, and 3-(2-aminoethylamino)propylmethyldimethoxysilane are preferred in terms of good adhesiveness of the cured product. Only one type of aminosilane coupling agent may be used, or two or more types may be used in combination. It has been noted that 3-(2-aminoethylamino)propyltrimethoxysilane is more irritating than other aminosilanes. The irritating effect can be alleviated by using 3-aminopropyltrimethoxysilane in combination with 3-(2-aminoethylamino)propyltrimethoxysilane instead of reducing the amount of 3-(2-aminoethylamino)propyltrimethoxysilane. Furthermore, silane coupling agents oligomerized by partial condensation of hydrolyzable silicon groups are also suitable in terms of safety and stability. The condensed silane coupling agents may be a single type or multiple types. Examples of oligomerized silane coupling agents include Dynasylan 1146 from Evonik. In terms of good storage stability of the curable composition, 3-aminopropyltrimethoxysilane and 3-(2-aminoethylamino)propylmethyldimethoxysilane are preferred.

[0108] Specific examples of silane coupling agents other than aminosilane coupling agents include epoxy group-containing silane coupling agents such as 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, and 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane; isocyanate group-containing silane coupling agents such as 3-isocyanatepropyltrimethoxysilane, 3-isocyanatepropyltriethoxysilane, 3-isocyanatepropylmethyldiethoxysilane, 3-isocyanatepropylmethyldimethoxysilane, (isocyanatemethyl)trimethoxysilane, and (isocyanatemethyl)dimethoxymethylsilane; and 3-mercaptopropyltrimethoxysilane and 3-mercaptopropyltriethoxysilane. Examples of suitable coupling agents include mercapto group-containing silane coupling agents such as 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropylmethyldiethoxysilane, and mercaptomethyltriethoxysilane; carboxy silane coupling agents such as 2-carboxyethyltriethoxysilane, 2-carboxyethylphenylbis(2-methoxyethoxy)silane, and N-2-(carboxymethylamino)ethyl-3-aminopropyltrimethoxysilane; vinyl-type unsaturated group-containing silane coupling agents such as vinyltrimethoxysilane, vinyltriethoxysilane, 3-methacryloyloxypropylmethyldimethoxysilane, and 3-acryloyloxypropylmethyltriethoxysilane; halogen-containing silane coupling agents such as 3-chloropropyltrimethoxysilane; and isocyanurate silane coupling agents such as tris(trimethoxysilyl)isocyanurate. Condensates obtained by partially condensing the above silane coupling agents can also be used. Examples of such condensates include Dynasylan 6490 and Dynasylan 6498 manufactured by Evonik.Furthermore, modified derivatives of these compounds, such as amino-modified silyl polymers, silylated amino polymers, unsaturated aminosilane complexes, phenylamino long-chain alkylsilanes, aminosilylated silicones, and silylated polyesters, can also be used as silane coupling agents.

[0109] Of these, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, and 3-glycidoxypropylmethyldimethoxysilane are preferred in terms of good adhesiveness of the cured product.

[0110] The above silane coupling agents may be used alone or in combination of two or more. The amount of the silane coupling agent used is preferably 0.1 to 20 parts by weight, more preferably 0.5 to 10 parts by weight, per 100 parts by weight of the total of the weight of the polyoxyalkylene polymer (A) and the weight of the (meth)acrylic polymer (B).

[0111] (plasticizer) The curable composition may contain a plasticizer. The addition of a plasticizer can adjust the viscosity and slump of the curable composition, as well as the mechanical properties such as tensile strength and elongation of the cured product.

[0112] Specific examples of plasticizers 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 compounds such as bis(2-ethylhexyl)-1,4-benzenedicarboxylate; hydrogenated phthalate compounds such as 1,2-cyclohexanedicarboxylic acid diisononyl ester; dioctyl adipate, dioctyl sebacate, dibutyl sebacate, dioctyl succinate; Examples of suitable oils include aliphatic polycarboxylic acid ester compounds such as isodecyl and tributyl acetyl citrate; unsaturated fatty acid ester compounds such as butyl oleate and methyl acetylricinoleate; alkylsulfonic acid phenyl esters; phosphate ester compounds such as tricresyl phosphate and tributyl phosphate; trimellitic acid ester compounds; chlorinated paraffins; hydrocarbon oils such as alkyldiphenyls and partially hydrogenated terphenyls; process oils; and epoxy plasticizers such as epoxidized soybean oil and benzyl epoxy stearate. A specific example of a terephthalic acid ester compound is EASTMAN168 (trade name, manufactured by EASTMAN CHEMICAL). A specific example of a non-phthalic acid ester compound is Hexamoll DINCH (trade name, manufactured by BASF). A specific example of an alkylsulfonic acid phenyl ester is Mesamoll (trade name, manufactured by LANXESS).

[0113] Polymeric plasticizers can also be used. The use of polymeric plasticizers allows the initial physical properties of the cured product to be maintained for a longer period of time than when low-molecular-weight plasticizers are used. Furthermore, the drying properties (paintability) of the cured product when coated with an alkyd paint are improved.

[0114] Specific examples of polymeric plasticizers include vinyl polymers, which are polymers of vinyl monomers; esters of polyalkylene glycols and polyols, such as diethylene glycol dibenzoate, triethylene glycol dibenzoate, and pentaerythritol ester; polyester plasticizers obtained from dibasic acids, such as sebacic acid, adipic acid, azelaic acid, and phthalic acid, and dihydric alcohols, such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, and dipropylene glycol; polyether polyols (polyoxyalkylene compounds), such as polyethylene glycol, polypropylene glycol, and polytetramethylene glycol, having a number-average molecular weight of 500 or more, or even 1,000 or more; derivatives of these polyether polyols in which the hydroxyl groups have been converted to ester groups, ether groups, or the like; polystyrenes, such as poly-α-methylstyrene; polybutadiene, polybutene, polyisobutylene, butadiene-acrylonitrile, and polychloroprene. Polymeric plasticizers are not limited to these.

[0115] The polymeric plasticizer is preferably compatible with the polyoxyalkylene polymer (A) and / or the (meth)acrylic polymer (B). From this viewpoint, polyethers and vinyl polymers are preferred. When polyethers are used as plasticizers, surface curability and deep curability are improved, and curing delay after storage does not occur. Among polyethers, polypropylene glycol is more preferred. Vinyl polymers are preferred from the viewpoint of compatibility with the polyoxyalkylene polymer (A) and / or the (meth)acrylic polymer (B) and the weather resistance and heat resistance of the cured product. Among vinyl polymers, acrylic polymers and / or methacrylic polymers are preferred, and acrylic polymers such as polyacrylic acid alkyl esters are more preferred. As a method for synthesizing vinyl polymers, living radical polymerization is preferred, and atom transfer radical polymerization is more preferred, since it produces polymers with narrow molecular weight distributions and low viscosity. Furthermore, the so-called SGO process, which is described in Japanese Patent Application Laid-Open No. 2001-207157 and involves continuous bulk polymerization of an acrylic acid alkyl ester monomer at high temperature and pressure, is also preferred as a method for producing a vinyl polymer.

[0116] The number average molecular weight of the polymer plasticizer is preferably 500 to 15,000, more preferably 800 to 10,000, still more preferably 1,000 to 8,000, particularly preferably 1,000 to 5,000, and most preferably 1,000 to 3,000. When the number average molecular weight of the polymer plasticizer is within the above range, the initial physical properties of the cured product can be maintained over a long period of time while preventing the plasticizer from leaking out from the cured product over time due to heat, rainfall, etc., and the curable composition has an appropriate viscosity and good workability. The molecular weight distribution of the polymeric plasticizer is not particularly limited, but is preferably narrow. Specifically, the molecular weight distribution is preferably less than 1.80, more preferably 1.70 or less, even more preferably 1.60 or less, still more preferably 1.50 or less, particularly preferably 1.40 or less, and most preferably 1.30 or less.

[0117] The number average molecular weight of vinyl polymers is measured by GPC. The number average molecular weight of polyether polymers is measured by end group analysis. The molecular weight distribution (Mw / Mn) is measured by GPC (polystyrene equivalent).

[0118] The polymeric plasticizer may or may not have a reactive silicon group. When the polymeric plasticizer has a reactive silicon group, it acts as a reactive plasticizer and can prevent the plasticizer from migrating from the cured product. When the polymeric plasticizer has a reactive silicon group, the number of reactive silicon groups per molecule is preferably 1 or less, more preferably 0.8 or less, on average. When using a plasticizer having a reactive silicon group, particularly a polyether polymer having a reactive silicon group, its number average molecular weight must be lower than the number average molecular weight of the polyoxyalkylene polymer (A) and / or the number average molecular weight of the (meth)acrylic polymer (B).

[0119] Among the plasticizers described above, at least one selected from the group consisting of phthalate esters, hydrogenated phthalate esters, and polyoxyalkylene compounds is preferred.

[0120] The amount of plasticizer used is preferably 5 to 150 parts by weight, more preferably 10 to 120 parts by weight, and even more preferably 20 to 100 parts by weight, per 100 parts by weight of the total weight of the polyoxyalkylene polymer (A) and the (meth)acrylic polymer (B). When the amount of plasticizer used is within the above range, it is possible to obtain the desired effects of using the plasticizer sufficiently, while forming a cured product excellent in mechanical strength. The plasticizer may be used alone, or two or more types may be used in combination. A low-molecular-weight plasticizer may be used in combination with a polymeric plasticizer. These plasticizers may be blended with the polyoxyalkylene polymer (A) or the (meth)acrylic polymer (B) when producing the polyoxyalkylene polymer (A) or the (meth)acrylic polymer (B).

[0121] (solvents, diluents) The curable composition may contain a solvent or a diluent. The solvent and diluent are not particularly limited. Examples of solvents and diluents that can be used include aliphatic hydrocarbons, aromatic hydrocarbons, alicyclic hydrocarbons, halogenated hydrocarbons, alcohols, esters, ketones, and ethers. When using a solvent or a diluent, the boiling point of the solvent is preferably 150°C or higher, more preferably 200°C or higher, and particularly preferably 250°C or higher, in order to prevent air pollution when the curable composition is used indoors. The above solvents or diluents may be used alone or in combination of two or more.

[0122] (thixotropic agent) The curable composition may contain a thixotropy-imparting agent, if necessary, to prevent sagging and improve workability. The thixotropy-imparting agent is not particularly limited. Examples of thixotropy-imparting agents include polyamide waxes; hydrogenated castor oil derivatives; and metal soaps such as calcium stearate, aluminum stearate, and barium stearate. Examples of trade names include Disparlon 6500, Disparlon 308, Disparlon 6300, Crayvallac SL, and Crayvallac SLT. These thixotropy-imparting agents may be used alone or in combination of two or more. The amount of the thixotropy-imparting agent used is preferably 0.1 to 20 parts by weight per 100 parts by weight of the total of the weight of the polyoxyalkylene polymer (A) and the weight of the (meth)acrylic polymer (B).

[0123] (antioxidant) The curable composition may contain an antioxidant (antiaging agent) other than the hindered phenol-based antioxidant (D). The use of an antioxidant can improve the weather resistance of the cured product. Examples of antioxidants other than the hindered phenol-based antioxidant (D) include monophenol-based compounds, bisphenol-based compounds, and polyphenol-based compounds. As the antioxidant, antioxidants such as SONGNOX 4120, Naugard 445, and OKABEST CLX050 can also be used. Specific examples of antioxidants are also described in Japanese Patent Application Laid-Open Nos. 4-283259 and 9-194731. The amount of antioxidant other than the hindered phenol-based antioxidant (D) used is preferably 0.1 to 10 parts by weight, more preferably 0.2 to 5 parts by weight, per 100 parts by weight of the total of the weight of the polyoxyalkylene polymer (A) and the weight of the (meth)acrylic polymer (B).

[0124] (light stabilizer) The curable composition may contain a light stabilizer other than the hindered amine light stabilizer (C). The use of a light stabilizer can prevent photooxidative deterioration of the cured product. Examples of light stabilizers include benzotriazole compounds and benzoate compounds. The amount of the light stabilizer other than the hindered amine light stabilizer (C) used is preferably 0.1 to 10 parts by weight, more preferably 0.2 to 5 parts by weight, per 100 parts by weight of the total of the weight of the polyoxyalkylene polymer (A) and the weight of the (meth)acrylic polymer (B). Specific examples of light stabilizers are described in, for example, JP-A-9-194731.

[0125] (ultraviolet absorber) The curable composition may contain an ultraviolet absorber. The use of an ultraviolet absorber can improve the surface weather resistance of the cured product. Examples of ultraviolet absorbers include benzophenone-based compounds, benzotriazole-based compounds, salicylate-based compounds, triazine-based compounds, substituted tolyl-based compounds, and metal chelate-based compounds. Among these, benzotriazole-based compounds are particularly preferred. Specific examples of benzotriazole-based compounds include Tinuvin 234, Tinuvin 326, Tinuvin 327, Tinuvin 328, Tinuvin 329, Tinuvin 350, Tinuvin 571, Tinuvin 900, Tinuvin 928, Tinuvin 1130, and Tinuvin 1600 (all manufactured by BASF); and SONGSORB 3290 (manufactured by SONGWON). Specific examples of triazine compounds include TINUVIN 400, TINUVIN 405, TINUVIN 477, and TINUVIN 1577ED (all manufactured by BASF), and SONGSORB CS400 and SONGSORB 1577 (manufactured by SONGWON).Specific examples of benzophenone compounds include SONGSORB 8100 (manufactured by SONGWON). The amount of the ultraviolet absorber used is preferably 0.1 to 10 parts by weight, more preferably 0.2 to 5 parts by weight, based on 100 parts by weight of the total of the weight of the polyoxyalkylene polymer (A) and the weight of the (meth)acrylic polymer (B). It is preferable to use a phenolic antioxidant or a hindered phenolic antioxidant in combination with a hindered amine light stabilizer and a benzotriazole ultraviolet absorber. Addworks IBC760 (manufactured by Clariant) can be used as a product containing a mixture of antioxidants, light stabilizers, and UV absorbers.

[0126] (Physical property adjuster) The curable composition may contain a physical property adjuster to adjust the tensile properties of the cured product, as needed. The physical property adjuster is not particularly limited. Examples of the physical property adjuster include alkylalkoxysilanes such as methyltrimethoxysilane, dimethyldimethoxysilane, trimethylmethoxysilane, and n-propyltrimethoxysilane; alkylisopropenoxysilanes such as dimethyldiisopropenoxysilane, methyltriisopropenoxysilane, and 3-glycidoxypropylmethyldiisopropenoxysilane; alkoxysilanes having functional groups such as 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, vinyltrimethoxysilane, vinyldimethylmethoxysilane, 3-aminopropyltrimethoxysilane, N-2-aminoethyl-3-aminopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, and 3-mercaptopropylmethyldimethoxysilane; silicone varnishes; and polysiloxanes. The use of a physical property modifier can increase the hardness of the cured product, or conversely, decrease the hardness of the cured product and increase the elongation at break. The physical property modifiers may be used alone or in combination of two or more.

[0127] In particular, compounds that hydrolyze to form a compound having a monovalent silanol group in the molecule have the effect of reducing the modulus of the cured product without increasing the stickiness of the surface of the cured product. Compounds that hydrolyze to form a compound having a monovalent silanol group in the molecule are particularly preferred, with compounds that form trimethylsilanol being particularly preferred. Examples of compounds that hydrolyze to form a compound having a monovalent silanol group in the molecule include the compounds described in JP-A-5-117521. Other examples include derivatives of alkyl alcohols such as hexanol, octanol, and decanol that hydrolyze to form trialkylsilanols such as trimethylsilanol, and derivatives of polyhydric alcohols with three or more hydroxyl groups such as trimethylolpropane, glycerin, pentaerythritol, and sorbitol that hydrolyze to form trialkylsilanols such as trimethylsilanol, as described in JP-A-11-241029. Examples include derivatives of oxyalkylene polymers that produce silicon compounds that produce trialkylsilanols such as trimethylsilanol upon hydrolysis, as described in JP-A-7-258534. Furthermore, polymers having crosslinkable hydrolyzable silicon-containing groups and silicon-containing groups that can be hydrolyzed to monosilanol-containing compounds, as described in JP-A-6-279693, can also be used. The physical property adjusting agent is used in an amount of 0.1 to 20 parts by weight, preferably 0.5 to 10 parts by weight, per 100 parts by weight of the total of the weight of the polyoxyalkylene polymer (A) and the weight of the (meth)acrylic polymer (B).

[0128] (tackifying resin) The curable composition may contain a tackifier resin for the purpose of increasing the adhesiveness or adhesion of the cured product to a substrate, etc. The tackifier resin is not particularly limited, and any tackifier resin commonly used in various curable compositions can be used. Specific examples of tackifying resins include terpene resins, aromatic modified terpene resins, hydrogenated terpene resins, terpene-phenol resins, phenol resins, modified phenol resins, xylene-phenol resins, cyclopentadiene-phenol resins, coumarone-indene resins, rosin resins, rosin ester resins, hydrogenated rosin ester resins, xylene resins, low-molecular-weight polystyrene resins, styrene copolymer resins, styrene block copolymers, hydrogenated styrene block copolymers, petroleum resins, hydrogenated petroleum resins, and DCPD resins. Examples of petroleum resins include C5 hydrocarbon resins, C9 hydrocarbon resins, and C5C9 hydrocarbon copolymer resins. These may be used alone or in combination. The amount of the tackifier resin used is preferably 2 to 100 parts by weight, more preferably 5 to 50 parts by weight, and even more preferably 5 to 30 parts by weight, per 100 parts by weight of the total weight of the polyoxyalkylene polymer (A) and the (meth)acrylic polymer (B). Using an amount of the tackifier resin within this range allows for the formation of a cured product with good adhesion and cohesion to the substrate. The curable composition has an appropriate viscosity, and the curable composition is easy to handle.

[0129] (compounds containing epoxy groups) The curable composition may contain a compound containing an epoxy group. The use of a compound having an epoxy group can improve the recovery of the cured product. Examples of compounds having an epoxy group include epoxidized unsaturated fats and oils, epoxidized unsaturated fatty acid esters, alicyclic epoxy compounds, epichlorohydrin derivatives, and mixtures thereof. Specific examples of compounds having an epoxy group include epoxidized soybean oil, epoxidized linseed oil, bis(2-ethylhexyl)-4,5-epoxycyclohexane-1,2-dicarboxylate (E-PS), epoxy octyl stearate, and epoxy butyl stearate. The amount of the epoxy group-containing compound used is preferably 0.5 to 50 parts by weight per 100 parts by weight of the total of the weight of the polyoxyalkylene polymer (A) and the weight of the (meth)acrylic polymer (B).

[0130] (epoxy resin) The curable composition may contain an epoxy resin. The curable composition containing an epoxy resin is preferred as an adhesive, particularly as an adhesive for exterior wall tiles. Examples of the epoxy resin include bisphenol A epoxy resins and novolac epoxy resins. The ratio of the total weight of the polyoxyalkylene polymer (A) and the (meth)acrylic polymer (B) to the weight of the epoxy resin is preferably in the range of 100 / 1 to 1 / 100, expressed as (weight of polymer (A) and weight of polymer (B)) / (weight of epoxy resin). When the polymers (A) and (B) are used with the epoxy resin in the above ratio, a high-strength cured product having excellent impact strength and toughness is easily formed. When an epoxy resin is used, the curable composition may contain a curing agent together with the epoxy resin. The type of curing agent is not particularly limited, and a commonly used curing agent can be used. The amount of the curing agent used is preferably 0.1 to 300 parts by weight based on 100 parts by weight of the epoxy resin.

[0131] (light curing substance) The curable composition may contain a photocurable substance. When a photocurable substance is used, a film of the photocurable substance is formed on the surface of the cured product, improving the stickiness and weather resistance of the cured product. Various compounds such as organic monomers, oligomers, and resins are known as photocurable substances. Many compositions containing photocurable substances are also known. Representative photocurable substances include unsaturated acrylic compounds, polyvinyl cinnamates, and azido resins. Examples of unsaturated acrylic compounds include monomers, oligomers, and mixtures thereof having one or more acrylic unsaturated groups or methacrylic unsaturated groups. The amount of the photocurable substance used is preferably 0.1 to 20 parts by weight, more preferably 0.5 to 10 parts by weight, per 100 parts by weight of the total of the weight of the polyoxyalkylene polymer (A) and the weight of the (meth)acrylic polymer (B). When the amount of the photocurable substance used falls within this range, a flexible cured product that is excellent in weather resistance and inhibits the occurrence of cracks is likely to be formed.

[0132] (oxygen curing substance) The curable composition may contain an oxygen-curing substance. Examples of oxygen-curing substances include unsaturated compounds that can react with oxygen in the air. When the curable substance contains an oxygen-curing substance, the oxygen-curing substance reacts with oxygen in the air to form a cured film near the surface of the cured product. The formation of a cured film on the surface of the cured product prevents stickiness and the adhesion of dirt and dust to the surface of the cured product. Specific examples of oxygen-curing substances include drying oils such as tung oil and linseed oil; various alkyd resins obtained by modifying drying oils; acrylic polymers, epoxy resins, and silicone resins modified with drying oils; and liquid polymers such as 1,2-polybutadiene, 1,4-polybutadiene, or polymers of C5-C8 dienes obtained by polymerizing or copolymerizing diene compounds such as butadiene, chloroprene, isoprene, or 1,3-pentadiene. These may be used alone or in combination of two or more. The amount of oxygen-curable substance used is preferably 0.1 to 20 parts by weight, more preferably 0.5 to 10 parts by weight, per 100 parts by weight of the total weight of the polyoxyalkylene polymer (A) and the (meth)acrylic polymer (B). Using an amount of oxygen-curable substance within this range makes it easier to form a cured product whose surface is less susceptible to contamination by dirt and dust and has excellent mechanical properties such as tensile strength. As described in JP-A-3-160053, the oxygen-curable substance is preferably used in combination with a photocurable substance.

[0133] <Method for producing curable composition> The curable composition is produced by a method including mixing a liquid resin component containing at least one of a polyoxyalkylene polymer (A) and a (meth)acrylic polymer (B) and having a temperature of 50°C or higher with a molten hindered phenol antioxidant (D). According to the above-described production method, it is possible to produce a curable composition that contains a polyoxyalkylene polymer having a reactive silicon group, a (meth)acrylic polymer having a reactive silicon group, a hindered amine light stabilizer, and a hindered phenol antioxidant, and that gives a cured product that is resistant to discoloration and surface tackiness in a weathering test.

[0134] The liquid resin component contains at least one of the polymer (A) and the polymer (B). The liquid resin component preferably contains the polymer (A) and the polymer (B). The liquid resin component preferably contains the entire amount of polymer (A) and polymer (B), but may contain only a portion of polymer (A) and polymer (B). The total weight of the polymer (A) and the polymer (B) contained in the liquid resin component is preferably 50% by weight or more, more preferably 70% by weight or more, even more preferably 80% by weight or more, even more preferably 90% by weight or more, and particularly preferably 100% by weight, based on the total weight of the polymer (A) and the polymer (B) contained in the curable composition.

[0135] The liquid resin component may contain a polymer other than polymer (A) and polymer (B) to the extent that the desired effect is not impaired. The polymer contained in the liquid resin component may be a polymer having a reactive silicon group, or may be a polymer having no reactive silicon group. The liquid resin component may contain a hindered amine light stabilizer (C) as long as the desired effect is not impaired. The temperature of the liquid resin component is preferably 200°C or lower, and may be 180°C or lower, or 150°C or lower.

[0136] The molten hindered phenol antioxidant (D) is mixed with a liquid resin component at a temperature of 50°C or higher. At this time, the molten hindered phenol antioxidant (D) and the hindered amine light stabilizer (C) may be added to the liquid resin component simultaneously. The temperature of the molten hindered phenol antioxidant (D) during mixing is preferably 200°C or lower, but may also be 180°C or lower, or 150°C or lower.

[0137] The method for mixing the liquid resin component at 50° C. or higher with the molten hindered phenol antioxidant (D) is not particularly limited, as long as the hindered phenol antioxidant (D) is mixed with the liquid resin component in a molten state. Examples of the mixing method include stirring and kneading using a mixer, roll, kneader, etc.

[0138] The hindered phenol-based antioxidant (D) is mixed in a molten state with the liquid resin component, whereby the hindered phenol-based antioxidant (D) dissolves in the liquid resin component. After the hindered phenol antioxidant (D) and the liquid resin component are mixed, the resulting mixture is preferably kept in a warm state for a predetermined time. The temperature at which the mixture is kept is not particularly limited as long as the mixture can be kept in a uniform molten state. The temperature during holding is, for example, preferably 200°C or lower, more preferably 180°C or lower, and even more preferably 150°C or lower. The retention time is preferably from 5 minutes to 120 minutes, more preferably from 10 minutes to 60 minutes, and even more preferably from 15 minutes to 30 minutes.

[0139] When the mixture obtained by the above method does not contain the entire amounts of polymer (A) and polymer (B), the remaining amounts of polymer (A) and polymer (B) are added to the mixture obtained by the above method. Furthermore, if necessary, a hindered amine light stabilizer (C) is added to the mixture obtained by the above method to produce a curable composition. When the mixture obtained by mixing the hindered phenol antioxidant (D) and the liquid resin component already contains the entire amount of the hindered amine light stabilizer (C), there is no need to add the hindered amine light stabilizer (C) to the mixture obtained by the above method. When a portion of the hindered amine light stabilizer (C) has been added to the mixture obtained by mixing the hindered phenol antioxidant (D) and the liquid resin component, the remaining amount of the hindered amine light stabilizer (C) is added to the mixture obtained by the above method.

[0140] As described above, the curable composition may contain various additives. The method for blending the various additives into the curable composition is not particularly limited. The various additives may be added to the liquid resin component, to the molten hindered phenol-based antioxidant (D), or to the above-mentioned mixture.

[0141] The curable composition can be prepared as a one-component composition in which all ingredients are mixed in advance and stored in a sealed container, and then cured by moisture in the air after application. When the curing agent composition contains a curing catalyst, the curable composition can also be prepared as a two-component composition in which a curing agent containing the curing catalyst and ingredients such as water is mixed with a separately prepared composition containing polymer (A) and polymer (B) before use. From the viewpoint of workability, the one-component composition is preferred. When the curable composition is a one-component type, all ingredients are premixed, and therefore, it is preferable to dehydrate and dry the ingredients containing water before use, or to dehydrate them under reduced pressure during blending and kneading. In addition to the dehydration and drying method, the storage stability can be further improved by adding an alkoxysilane compound such as methyltrimethoxysilane, phenyltrimethoxysilane, n-propyltrimethoxysilane, vinyltrimethoxysilane, vinylmethyldimethoxysilane, γ-mercaptopropylmethyldimethoxysilane, γ-mercaptopropylmethyldiethoxysilane, or γ-glycidoxypropyltrimethoxysilane. Partially condensed silane compounds such as Evonik's Dynasylan 6490 can also be used as dehydrating agents from the standpoint of safety and stability. The amount of the dehydrating agent, particularly a silicon compound capable of reacting with water such as vinyltrimethoxysilane, used is preferably 0.1 to 20 parts by weight, more preferably 0.5 to 10 parts by weight, per 100 parts by weight of the total of the weight of the polyoxyalkylene polymer (A) and the weight of the (meth)acrylic polymer (B).

[0142] The curable composition can be obtained by the above-described production method. The obtained curable composition was cured under conditions of 23°C and 55% relative humidity to obtain a test piece consisting of a 3 mm thick sheet-like cured product, and the illuminance was 435 mW / cm 2 More than 470mW / cm 2 The cumulative light intensity is 10,000mJ / cm 2 More than 12,000mJ / cm 2 When irradiated with UV light as described below, the cured product preferably has a rolling distance measured in accordance with ASTM D 3121 of more than 150 mm, more preferably more than 200 mm.

[0143] The test specimens were cured at 23°C and 55% relative humidity until they were tack-free. A tack-free state means that the surface of the cured product is not sticky at all when touched with a finger.

[0144] As an accelerated weathering test, the above test specimens were subjected to an illuminance of 435mW / cm 2 More than 470mW / cm 2 The cumulative light intensity is 10,000mJ / cm 2 More than 12,000mJ / cm 2 Irradiate with UV light at the following: Note that variations in illuminance and integrated light quantity inevitably occur due to the method of accelerated weathering test and the equipment used in the accelerated weathering test. Taking this into consideration, the above illuminance and integrated light quantity are set within a certain range. If the illuminance and the integrated amount of light are within the above ranges, there is almost no effect on the results of the accelerated weathering test.

[0145] <Uses of the curable composition> The curable composition can be used as a construction sealant, industrial adhesive, waterproof coating composition, pressure-sensitive adhesive raw material, and the like. The curable composition can also be used as a sealant for buildings, ships, automobiles, roads, and the like. Furthermore, the curable composition, alone or with the aid of a primer, can adhere to a wide range of substrates, including glass, porcelain, wood, metal, and resin moldings. Therefore, the curable composition can also be used as various types of sealing and adhesive compositions. In addition to conventional adhesives, the curable composition can also be used as a contact adhesive. Furthermore, the curable composition is useful as a food packaging material, a cast rubber material, a molding material, and a paint. The cured product of the above curable composition exhibits low water absorption. Therefore, the above curable composition and its cured product are particularly suitable for waterproof materials, such as sealants, waterproof adhesives, and waterproof coatings.

[0146] <Method for producing cured product> Before curing, the curable composition is formed into a desired shape by a method such as coating, casting, or filling.

[0147] The curable composition that has been applied, cast, or filled and shaped is cured under a desired environment, such as room temperature and humidity.

[0148] The cured product thus formed exhibits good adhesion to a variety of adherends, and in particular, exhibits excellent adhesion to materials commonly used as building materials, such as rigid polyvinyl chloride resin, mortar, and concrete. [Example]

[0149] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples.

[0150] Example 1 A curable composition was prepared using the components shown below. Specifically, 100 parts by weight of polymer (AB-1) at 85°C and 0.2 parts by weight of a molten hindered phenol-based antioxidant were kneaded at 85°C using a centrifugal mixer (Thinky Corporation, product name: Awatori Rentaro). During kneading, polymer (AB-1) and the hindered phenol-based antioxidant were rotated at 1600 rpm for 1.5 minutes and then rotated at 2200 rpm for 5 minutes. After kneading, 0.25 parts by weight of a hindered amine-based light stabilizer was mixed with the resulting mixture to prepare a curable composition.

[0151] The components used in Example 1 are as follows: Polymer (AB-1): A polymer comprising a polyoxypropylene polymer (A-1) having a dimethoxymethylsilyl group (hereinafter also referred to as polymer (A-1)), and a (meth)acrylic acid ester polymer (B-1) having a dimethoxymethylsilyl group (hereinafter also referred to as polymer (B-1)). Hindered phenolic antioxidant: bis[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionic acid][ethylenebis(oxyethylene)] (manufactured by BASF, trade name: Irganox 245 (Irg245)) Hindered amine light stabilizer: a mixed ester compound of 1,2,3,4-butanetetracarboxylic acid, 1,2,2,6,6-pentamethyl-4-biperidinol, and 3,9-bis(2-hydroxy-1,1-dimethylethyl)-2,4,8,10-tetraoxaspiro[5.5]undecane (manufactured by ADEKA Corporation, trade name: Adekastab LA-63P)

[0152] <Method for producing polymer (AB-1)> (Polyoxypropylene polymer (A-1) having dimethoxymethylsilyl groups) Using polyoxypropylene glycol with a number-average molecular weight of approximately 4500 as an initiator, propylene oxide was polymerized with a zinc hexacyanocobaltate glyme complex catalyst to obtain polyoxypropylene (P-1) with a number-average molecular weight of 27,900 (17,700 molecular weight calculated as the terminal group) and a molecular weight distribution (Mw / Mn) of 1.21, bearing hydroxyl groups at both ends. Subsequently, 1.2 molar equivalents of sodium methoxide were added to the hydroxyl groups of the hydroxyl-terminated polyoxypropylene (P-1) as a 28% methanol solution. After removing the methanol by vacuum devolatilization, an additional 1.5 molar equivalents of allyl chloride was added to the hydroxyl groups of the polymer (P-1) to convert the terminal hydroxyl groups to allyl groups. Unreacted allyl chloride was then removed by vacuum devolatilization. The resulting crude polyoxypropylene was mixed with n-hexane and water, stirred, and the water was removed by centrifugation. The resulting hexane solution was then devolatilized under reduced pressure to remove metal salts from the polymer. This resulted in the production of polyoxypropylene (Q-1) having allyl groups at its termini. 500 g of this polymer (Q-1) was mixed with 50 μL of a platinum divinyldisiloxane complex solution (a 3 wt. % platinum equivalent isopropanol solution), and 4.8 g of dimethoxymethylsilane was slowly added dropwise while stirring. The resulting mixture was reacted at 100°C for 2 hours, after which the unreacted dimethoxymethylsilane was distilled off under reduced pressure to produce polyoxypropylene polymer (A-1) having dimethoxymethylsilyl groups at its termini and a number-average molecular weight of approximately 28,500. Polymer (A-1) contained an average of 0.8 dimethoxymethylsilyl groups at each terminus, with an average of 1.6 per molecule.

[0153] ((Meth)acrylic acid ester polymer (B-1) having dimethoxymethylsilyl group) A mixture of 43 g of methyl methacrylate, 204 g of butyl acrylate, 45 g of stearyl methacrylate, 7.2 g of γ-methacryloxypropyldimethoxymethylsilane, and 13 g of IBA was added dropwise to 180 g of isobutyl alcohol (IBA) heated to 105°C over 5 hours. A solution of 1.4 g of azobis-2-methylbutyronitrile as a polymerization initiator was then added dropwise to 4.5 g of IBA over 1 hour. Polymerization was then carried out after 2 hours, yielding a (meth)acrylic acid ester copolymer (B-1) with a solids concentration of 60%, a number-average molecular weight of 17,800, and an average of 1.83 dimethoxymethylsilyl groups per molecule.

[0154] (Polymer (AB-1)) The obtained (meth)acrylic acid ester copolymer (B-1) was mixed with 70 parts by weight of polyoxypropylene (A-1) having dimethoxymethylsilyl groups so that the solid content of the (meth)acrylic acid ester copolymer was 30 parts by weight, and after uniform mixing, the IBA was distilled off using a rotary evaporator to obtain an organic polymer (AB-1).

[0155] In the polymer (AB-1), the weight W of the acrylic polymer B Weight W of polyoxyalkylene polymer A Ratio of W A / W B However, it is 70 / 30.

[0156] The molecular weight of the above hindered phenol-based antioxidant is 587. Two hydroxy groups are present in one molecule of the above hindered phenol-based antioxidant.

[0157] The molecular weight of the hindered amine light stabilizer is 2000. There are six nitrogen atoms in one molecule of the hindered amine light stabilizer.

[0158] The number of moles of hydroxyl groups in the hindered phenol antioxidant, N OHThe number of moles N of nitrogen atoms contained in the hindered amine light stabilizer relative to N Ratio of N N / N OH was calculated according to the following formula: N N / N OH = (content of hindered amine light stabilizer in curable composition × 6 / 2000) / (content of hindered phenol antioxidant in curable composition × 2 / 587)

[0159] The obtained curable composition was filled into a mold and cured at 23°C and a relative humidity of 55% for 7 days to produce a sheet-like cured product having a thickness of about 3 mm. The resulting cured product was cured using a tabletop conveyor UV curing device (LC-6B, manufactured by Excelitas Noble Light Japan Co., Ltd.) at an illuminance of 435 mW / cm 2 More than 470mW / cm 2 The cumulative light intensity is 10,000mJ / cm 2 More than 12,000mJ / cm 2 An accelerated weathering test was conducted by irradiating UV light so as to satisfy the following conditions. The actual irradiance and cumulative light amount irradiated in the accelerated weathering test are shown in Table 1.

[0160] (Tack rating) To evaluate the tackiness of the surface of the cured product after the accelerated weathering test, the distance a ball (size 4) rolled on the sample sheet (hereinafter also referred to as the rolling distance) was measured in accordance with ASTM D 3121. A rolling ball tack tester (PSTC-6, size: 21 cm (width) × 7 cm (length) × 8 cm (height)) was used to measure the rolling distance. The obtained rolling distance was evaluated according to the following criteria. The evaluation results are shown in Table 1. Furthermore, a cured product after the accelerated weathering test that has an evaluation result of 4 or 5 can be evaluated as a cured product that is less likely to develop tack on the surface. 5: The rolling distance is more than 200 mm. 4: The rolling distance is more than 150 mm and less than 200 mm. 3: The rolling distance is more than 100 mm and less than 150 mm. 2: The rolling distance is more than 50 mm and less than 100 mm. 1: The rolling distance is 50 mm or less.

[0161] (Coloring evaluation) The change in hue of the cured product after the accelerated weathering test relative to the hue before the test was visually observed, and the colorability of the cured product was evaluated based on the degree of observed change in hue according to the following criteria. The evaluation results are shown in Table 1. 3: The hue of the cured product after the accelerated weathering test is unchanged from the hue of the cured product before the accelerated weathering test. 2: The hue of the cured product after the accelerated weathering test is slightly different from the hue of the cured product before the accelerated weathering test. 1: The hue of the cured product after the accelerated weathering test is significantly different from the hue of the cured product before the accelerated weathering test.

[0162] (tensile properties) The sheet-like cured product obtained by the above method was punched into a No. 3 dumbbell shape to obtain a test specimen according to JIS K 6251. The obtained test specimen was subjected to a tensile test (maximum load = 5 N, tensile speed = 200 mm / min) using an autograph (product name: AGS-J, manufactured by Shimadzu Corporation) at 23°C and a relative humidity of 50%. The measurement results of the 100% modulus (M100), breaking strength (Tb), and breaking elongation (Eb) are shown in Table 1.

[0163] Examples 2 to 5 Curable compositions and cured products were obtained in the same manner as in Example 1, except that the content of each component was changed to the content shown in Table 1. The content of each component in Tables 1 to 4 is shown in parts by weight.

[0164] Examples 6 to 9 The (meth)acrylic acid ester copolymer (B-1) obtained by the above-described production method and the polyoxypropylene polymer (A-1) having a dimethoxymethylsilyl group were uniformly mixed in the amounts shown in Table 2, and then the IBA was distilled off from the mixture using a rotary evaporator to obtain a mixture of the polymer (A-1) and the polymer (B-1). A curable composition and a cured product were obtained in the same manner as in Example 1, except that polymer (AB-1) was changed to a mixture of polymer (A-1) and polymer (B-1) and the content of each component was changed to the content shown in Table 2.

[0165] Example 10 A curable composition and a cured product were obtained in the same manner as in Example 1, except that polymer (AB-1) was changed to a mixture of polymer (AB-1) and polymer (A-1) and the content of each component was changed to the content shown in Table 2.

[0166] (Comparative Example 1) A curable composition and a cured product were obtained in the same manner as in Example 1, except that no hindered amine-based light stabilizer was used and the content of each component was changed to the content shown in Table 3.

[0167] (Comparative Examples 2 to 4) A curable composition and a cured product were obtained in the same manner as in Example 1, except that the polymer (AB-1) at 23°C and a powdered hindered phenol-based antioxidant were kneaded at 23°C instead of kneading the polymer (AB-1) at 85°C and a molten hindered phenol-based antioxidant at 85°C, and the content of each component was changed to the content shown in Table 3.

[0168] (Comparative Example 5) 80 parts by weight of the (meth)acrylic acid ester copolymer (B-1) obtained by the above-mentioned production method and 20 parts by weight of a polyoxypropylene polymer (A-1) having a dimethoxymethylsilyl group were uniformly mixed, and then the IBA was removed from the mixture using a rotary evaporator, thereby obtaining a mixture of 20 parts by weight of polymer (A-1) and 80 parts by weight of polymer (B-1). A curable composition and a cured product were obtained in the same manner as in Comparative Example 2, except that polymer (AB-1) was changed to a mixture of 20 parts by weight of polymer (A-1) and 80 parts by weight of polymer (B-1) and that the content of each component was changed to the content shown in Table 3.

[0169] (Comparative Example 6) A curable composition and a cured product were obtained in the same manner as in Comparative Example 2, except that polymer (AB-1) was changed to a mixture of polymer (AB-1) and polymer (A-1) and the content of each component was changed to the content shown in Table 3.

[0170] (Comparative Example 7) A curable composition and a cured product were obtained in the same manner as in Example 1, except that polymer (AB-1) was changed to polymer (A-1) and the content of each component was changed to the content shown in Table 4.

[0171] (Comparative Example 8) IBA was distilled off from the (meth)acrylic acid ester copolymer (B-1) obtained by the above-mentioned production method using a rotary evaporator. A curable composition and a cured product were obtained in the same manner as in Example 1, except that the polymer (AB-1) was changed to the polymer (B-1) from which IBA had been distilled off, and the contents of each component were changed to the contents shown in Table 4.

[0172] (Comparative Examples 9 to 10) The (meth)acrylic acid ester copolymer (B-1) obtained by the above-described production method and the polyoxypropylene polymer (A-1) having a dimethoxymethylsilyl group were uniformly mixed in the amounts shown in Table 4, and then the IBA was removed from the mixture using a rotary evaporator, thereby obtaining a mixture of the polymer (A-1) and the polymer (B-1). A curable composition and a cured product were obtained in the same manner as in Example 1, except that polymer (AB-1) was changed to a mixture of polymer (A-1) and polymer (B-1) and the content of each component was changed to the content shown in Table 4.

[0173] For the cured products of Examples 2 to 10 and Comparative Examples 1 to 10, the actual illuminance and integrated light quantity irradiated in an accelerated weathering test were measured, and tack, coloration, and tensile properties were evaluated in the same manner as in Example 1. The results are shown in Tables 1 to 4. In the tensile tests of Comparative Examples 5, 8, and 10, the 50% modulus (M50) was measured instead of the 100% modulus (M100).

[0174] [Table 1]

[0175] [Table 2]

[0176] [Table 3]

[0177] [Table 4]

[0178] Tables 1 to 4 show that when the cured products of the curable compositions of Examples 1 to 10 were subjected to an accelerated weathering test, there was little discoloration and the surface of the cured products was less likely to develop tack. In contrast, when an accelerated weathering test was conducted on the cured product of the curable composition of Comparative Example 1, which did not contain a hindered amine light stabilizer, it was found that coloration and tack occurred on the surface of the cured product. Furthermore, when an accelerated weathering test was performed on the cured products of the curable compositions of Comparative Examples 2 to 6, which were obtained by mixing a powdered hindered phenol antioxidant with a liquid resin component, it was found that tackiness occurred on the surface of the cured products. Furthermore, when an accelerated weathering test was performed on the cured products of the curable composition of Comparative Example 8, which did not contain a polyoxyalkylene polymer having a reactive silicon group, and the cured product of the curable composition of Comparative Example 7, which did not contain a (meth)acrylic polymer having a reactive silicon group, it was found that tackiness occurred on the surface of the cured products.

[0179] Furthermore, Tables 1 and 3 show that the cured product of the curable composition of Example 1 exhibits a smaller 100% modulus and a larger breaking strength (Tb) and breaking elongation (Eb) than the cured product of the curable composition of Comparative Example 2. This indicates that the cured product of the curable composition of Example 1 is less likely to break than the cured product of the curable composition of Comparative Example 2, and is therefore more suitable for use as a sealant or adhesive.

Claims

1. A method for producing a curable composition comprising (A) a polyoxyalkylene polymer having a reactive silicon group, (B) a (meth)acrylic polymer having a reactive silicon group, (C) a hindered amine light stabilizer, and (D) a hindered phenol antioxidant, the method comprising: the production method includes mixing a liquid resin component containing at least one of the polyoxyalkylene polymer (A) and the (meth)acrylic polymer (B) and having a temperature of 50°C or higher with the molten hindered phenol antioxidant (D), The (meth)acrylic polymer (B) contains a structural unit derived from a (meth)acrylic acid alkyl ester.

2. The number of moles N of the hydroxyl groups contained in the hindered phenol-based antioxidant (D) is ＯＨ The molar number N of nitrogen atoms contained in the hindered amine light stabilizer (C) relative to Ｎ Ratio of N Ｎ / N ＯＨ The method according to claim 1, wherein is 0.1 to 10.

3. The weight W of the (meth)acrylic polymer (B) Ｂ The weight W of the polyoxyalkylene polymer (A) relative to Ａ Ratio of W Ａ / W Ｂ The method according to claim 1, wherein the ratio of the total weight of the polymer to the total weight of the polymer is 20 / 80 to 80 / 20.

4. The curable composition was cured at 23°C and a relative humidity of 55% to obtain a test piece of a 3 mm thick sheet-like cured product, and the illuminance was 435 mW / cm ２ More than 470mW / cm ２ Below, the cumulative light intensity is 10,000 mJ / cm ２ 12,000mJ / cm or more ２ 2. The method of claim 1, wherein the cured product has a rolling distance of more than 150 mm when irradiated with UV light at or below 1000 kJ / cm2, as measured in accordance with ASTM D 3121.

5. A curable composition produced by the method according to any one of claims 1 to 3.

6. The curable composition was cured at 23°C and a relative humidity of 55% to obtain a test piece of a 3 mm thick sheet-like cured product, and the illuminance was 435 mW / cm ２ More than 470mW / cm ２ Below, the cumulative light intensity is 10,000 mJ / cm ２ 12,000mJ / cm or more ２ 6. The curable composition of claim 5, wherein the cured product has a rolling distance of greater than 150 mm when irradiated with UV light at or below 100°C, as measured in accordance with ASTM D 3121.

Images