Curable composition

Abstract

To provide a curable composition containing a hydrolyzable silyl group-containing polymer, which achieves both roller coatability and resistance to sagging after coating.SOLUTION: The curable composition includes a polymer (A) having a hydrolyzable silyl group, a plasticizer (B), a filler (C), a rheology modifier (D), and a curing catalyst (E). (A) contains a polyoxyalkylene polymer (A1) having more than one hydrolyzable silyl group on average at one terminal site and a polyoxyalkylene polymer (A2) having one or less hydrolyzable silyl group on average at one terminal site, and (A1): (A2) is 20:80 to 80:20 on a weight basis. (C) contains kaolin and calcium carbonate having an average particle diameter of 2.0 to 4.5 μm. (A) is 12 to 25% by weight, (B) is 20 to 35% by weight, and (C) is 40 to 60% by weight, based on the total weight of the curable composition. (D) is 0.6 to 7 parts by weight with respect to 100 parts by weight of (A).SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a curable composition containing a polymer having a hydrolyzable silyl group, and a method for producing a cured film using the composition. [Background technology]

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

[0003] Among these organic polymers, polyoxyalkylene polymers having hydrolyzable silyl groups are widely used in applications such as sealants and adhesives because of their well-balanced performance in the cured product, including mechanical properties, weather resistance, and dynamic durability.

[0004] In order to efficiently apply a curable composition containing a polyoxyalkylene polymer having a hydrolyzable silyl group to a large substrate, it is expected that application will be carried out using a roller or a spray.

[0005] Patent Document 1 discloses a curable composition for spray coating, which contains a polymer having a hydrolyzable silyl group, a plasticizer, a filler having an average particle size of 0.5 to 4 μm, and a catalyst. This document discloses a formulation suitable for spray coating, but does not consider a formulation suitable for roller coating. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2023-7423 Summary of the Invention [Problem to be solved by the invention]

[0007] One application under consideration for a curable composition containing a hydrolyzable silyl group-containing polyoxyalkylene polymer is to apply the composition to the wall surface of a building or the like, and then cure the composition to form a waterproof film.

[0008] In such applications, the curable composition is required to have properties that allow an operator to easily apply the composition using a roller (roller coatability), and in addition, the coating film is required to be resistant to sagging after application until the composition is cured.

[0009] Generally, lowering the viscosity of a composition improves roller applicability, but the coating becomes more prone to dripping after application, so it is not easy to achieve both roller applicability and resistance to dripping.

[0010] In view of the above-mentioned current situation, an object of the present invention is to provide a curable composition containing a hydrolyzable silyl group-containing polymer that combines roller coatability with resistance to sagging after coating. [Means for solving the problem]

[0011] As a result of intensive research to solve the above-mentioned problems, the present inventors have found that it is possible to achieve both roller coatability and resistance to sagging after coating by using, as the hydrolyzable silyl group-containing polymer, two types of polyoxyalkylene polymers that differ in the average number of hydrolyzable silyl groups per terminal portion of the polymer, in combination with a plasticizer, two specific fillers, and a rheology modifier, and have completed the present invention.

[0012] That is, the present invention provides a curable composition comprising a polymer (A) having a hydrolyzable silyl group, a plasticizer (B), a filler (C), a rheology modifier (D), and a curing catalyst (E), the polymer (A) comprises a polyoxyalkylene polymer (A1) having more than one hydrolyzable silyl group on average at one terminal site, and a polyoxyalkylene polymer (A2) having one or less hydrolyzable silyl group on average at one terminal site, and the ratio of the content of (A1) to the content of (A2) is 20:80 to 80:20 by weight; The filler (C) contains kaolin and calcium carbonate having an average particle size of 2.0 to 4.5 μm, the content of the polymer (A) is 12 to 25% by weight, the content of the plasticizer (B) is 20 to 35% by weight, and the content of the filler (C) is 40 to 60% by weight, based on the total weight of the curable composition; The curable composition has a content of the rheology modifier (D) of 0.6 to 7 parts by weight based on 100 parts by weight of the polymer (A). The present invention also relates to a method for producing a cured film, which comprises the steps of applying the curable composition by roller coating and curing the composition. [Effects of the Invention]

[0013] According to the present invention, it is possible to provide a curable composition containing a hydrolyzable silyl group-containing polymer that has both roller coatability and resistance to sagging after coating. The curable composition according to the present invention is suitable for application using a roller, and the roller rolls easily during application, reducing the burden on the worker. Furthermore, the curable composition has the advantages of easily spreading the coating film and being less sticky. Furthermore, the curable composition according to the present invention has the advantages of being able to obtain a coating film of sufficient thickness and being less likely to drip after application. DETAILED DESCRIPTION OF THE INVENTION

[0014] An embodiment of the present invention will be described below. <<Hydrolyzable Silyl Group-Containing Polymer (A)>> The curable composition according to the present disclosure contains a polymer (A) having a hydrolyzable silyl group as a curable resin.

[0015] <Hydrolyzable silyl group> The polymer (A) has a hydrolyzable silyl group. The hydrolyzable silyl group is a silicon group that has a hydroxyl group or a hydrolyzable group on the silicon atom and can form a siloxane bond by a hydrolysis-condensation reaction. Specifically, it is represented by the following general formula (1): -SiR 3 3-a X a (1) In formula (1), R 3 represents a substituted or unsubstituted hydrocarbon group having 1 to 20 carbon atoms. X represents a hydroxyl group or a hydrolyzable group. a is 1, 2, or 3.

[0016] R 3 The hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms, and even more preferably 1 to 3 carbon atoms. 3 Specific examples of R include a methyl group, an ethyl group, a chloromethyl group, a methoxymethyl group, and an N,N-diethylaminomethyl group. Preferred are a methyl group, an ethyl group, a chloromethyl group, and a methoxymethyl group, and more preferred are a methyl group and a methoxymethyl group. 3 When there are a plurality of, they may be the same or different.

[0017] Examples of X include a hydroxyl group, a halogen, an alkoxy group, an acyloxy group, a ketoximate group, an amino group, an amide group, an acid amide group, an aminooxy group, a mercapto group, and an alkenyloxy group. Among these, alkoxy groups such as a methoxy group and an ethoxy group are more preferred because they are mildly hydrolyzable and easy to handle, and a methoxy group and an ethoxy group are particularly preferred. When there are multiple Xs, they may be the same or different.

[0018] a is 1, 2, or 3. Since the strength of the cured product is improved, a is preferably 2 or 3. It is more preferable that a is 2, since this makes it easier to achieve both strength and elongation in the cured product.

[0019] Specific examples of the hydrolyzable silyl group contained in the polymer (A) include, but are not limited to, a trimethoxysilyl group, a triethoxysilyl group, a tris(2-propenyloxy)silyl group, a triacetoxysilyl group, a dimethoxymethylsilyl group, a diethoxymethylsilyl group, a dimethoxyethylsilyl group, a (chloromethyl)dimethoxysilyl group, a (chloromethyl)diethoxysilyl group, a (methoxymethyl)dimethoxysilyl group, a (methoxymethyl)diethoxysilyl group, an (N,N-diethylaminomethyl)dimethoxysilyl group, and an (N,N-diethylaminomethyl)diethoxysilyl group. Among these, methyldimethoxysilyl, trimethoxysilyl, triethoxysilyl, (chloromethyl)dimethoxysilyl, (methoxymethyl)dimethoxysilyl, (methoxymethyl)diethoxysilyl, and (N,N-diethylaminomethyl)dimethoxysilyl groups are preferred because they exhibit high activity and yield cured products with good mechanical properties. Methyldimethoxysilyl is preferred because it has excellent shape retention after coating.

[0020] The polymer (A) comprises a polyoxyalkylene polymer (A1) having, on average, more than one hydrolyzable silyl group at each terminal, and a polyoxyalkylene polymer (A2) having, on average, one or less hydrolyzable silyl group at each terminal. The combined use of the polymer (A1) and the polymer (A2) reduces the viscosity of the curable composition during roller coating, achieving good roller coatability, while also improving the strength of the cured product.

[0021] With regard to the polymer (A1), "having on average more than one hydrolyzable silyl group at one terminal position" means that the polymer (A1) contains polyoxyalkylene molecules having two or more hydrolyzable silyl groups at one terminal position. The polyoxyalkylene polymer (A1) may contain only polyoxyalkylene molecules having two or more hydrolyzable silyl groups at one terminal position, or may contain both polyoxyalkylene molecules having two or more hydrolyzable silyl groups at one terminal position and polyoxyalkylene molecules having one hydrolyzable silyl group at one terminal position.

[0022] The multiple terminal sites possessed by one polyoxyalkylene molecule may include both terminal sites having two or more hydrolyzable silyl groups and terminal sites having one hydrolyzable silyl group. Furthermore, the polyoxyalkylene polymer (A1) may contain polyoxyalkylene molecules having, on average, more than one hydrolyzable silyl group at one terminal site, but having no hydrolyzable silyl group.

[0023] The terminal moiety having two or more hydrolyzable silyl groups can be represented, for example, by the following general formula (2).

[0024] [ka]

[0025] In formula (2), R 1 , and R 2 are each independently a divalent organic group having 1 to 10 carbon atoms which may contain a heteroatom. n is an integer of 1 to 6. R 3 , X, and a are as described above for formula (1).

[0026] R 1 , R 2R is a divalent organic group having 1 to 10 carbon atoms which may contain a heteroatom. The number of carbon atoms in the organic group is preferably 1 to 8, more preferably 1 to 6, and even more preferably 1 to 4. 1 Specific examples of R include -CH2OCH2-, -CH2OCH2CH2-, -CH2OCH2CH2-, -CH2OCH2CH2(CH3)CH2-, and -CH2OCH2CH2CH2-, and preferably -CH2OCH2CH2CH2-. 2 Specific examples include -CH2CH2CH2-, -CH2CH2(CH3)CH2-, -C(O)NHCH2CH2CH2-, and -C(O)NHCH2-, and preferably -CH2CH2CH2-.

[0027] In a particularly preferred embodiment, the terminal moiety represented by general formula (2) is R 1 is -CH2OCH2CH2CH2- and R 2 is -CH2CH2CH2-.

[0028] n is preferably an integer of 1 to 5, more preferably an integer of 1 to 3, and even more preferably 1 or 2. However, within one molecule of polymer (A) or in an aggregate of multiple molecules of polymer (A), n is not limited to a single value and may have multiple values ​​mixed together. Furthermore, a terminal portion where n=0 may be included in a portion of the aggregate of molecules.

[0029] In the polyoxyalkylene polymer (A1), the average number of hydrolyzable silyl groups per terminal is preferably more than 1.0. The average number is more preferably 1.1 or more, even more preferably 1.5 or more, and even more preferably 2.0 or more. The average number is preferably 5 or less, and more preferably 3 or less.

[0030] The number of terminal moieties having multiple hydrolyzable silyl groups contained in one molecule of the polyoxyalkylene polymer (A1) is preferably 0.5 or more, more preferably 1.0 or more, even more preferably 1.1 or more, and even more preferably 1.5 or more on average, and is preferably 4 or less, more preferably 3 or less.

[0031] The polyoxyalkylene polymer (A1) may have hydrolyzable silyl groups in positions other than the terminal positions, but it is preferable to have them only in the terminal positions, as this makes it easier to obtain a rubber-like cured product that has high elongation and a low elastic modulus.

[0032] The average number of hydrolyzable silyl groups per molecule of the polyoxyalkylene polymer (A1) is preferably more than 1.0, more preferably 1.2 or more, even more preferably 1.3 or more, even more preferably 1.5 or more, and particularly preferably 1.7 or more, from the viewpoint of the strength of the cured product, and is preferably 6.0 or less, more preferably 5.5 or less, and most preferably 5.0 or less, from the viewpoint of the elongation of the cured product.

[0033] On the other hand, the terminal structure of the polyoxyalkylene polymer (A2) having one or less hydrolyzable silyl group on average at one terminal site can be represented by, for example, the following general formula (3). -OR 2 -SiR 3 3-a X a (3) In formula (3), R 2 is as described above for formula (2), and R 3 , X, and a are as described above for formula (1).

[0034] The number of hydrolyzable silyl groups in one molecule of the polyoxyalkylene polymer (A2) is preferably 1 to 7 on average, more preferably 1.1 to 3.4, and particularly preferably 1.2 to 2.6, from the viewpoint of the balance between the viscosity of the curable composition and the strength of the cured product.

[0035] The number of hydrolyzable silyl groups in the polymer (A2) is preferably 0.5 or more, more preferably 0.6 or more, even more preferably 0.7 or more, and particularly preferably 0.8 or more, on average at one terminal site of the polymer (A1), because this provides good curability and facilitates the development of rubber-like elastic behavior. In addition, in order to obtain a good rubber-like cured product, the hydrolyzable silyl groups in the polymer (A2) are preferably present at the terminals of the main chain.

[0036] <Main chain structure> The main chain of the polyoxyalkylene polymers (A1) and (A2) is a polymer having a repeating unit represented by -RO-, where R is preferably a linear or branched alkylene group having 1 to 14 carbon atoms, more preferably a linear or branched alkylene group having 2 to 4 carbon atoms.

[0037] Specific examples of the repeating unit represented by -RO- include -CHO-, -CHCHO-, -CHCH(CH)O-, -CHC(CH)(CH)O-, and -CHCHCHCHO-, with -CHCHO- and -CHCH(CH)O- being preferred, and -CHCH(CH)O- being more preferred.

[0038] In particular, polyoxypropylene polymers having oxypropylene repeating units in an amount of preferably 50% by weight or more, more preferably 80% by weight or more of the polymer main chain structure are preferred because they are amorphous and have a relatively low viscosity.

[0039] The number average molecular weight of each of the polyoxyalkylene polymers (A1) and (A2), as measured by GPC in terms of polystyrene, is preferably from 3,000 to 100,000, more preferably from 3,000 to 50,000, and particularly preferably from 3,000 to 30,000. When the number average molecular weight is 3,000 or more, the amount of hydrolyzable silyl groups introduced can be easily adjusted to an appropriate range, and when it is 100,000 or less, the viscosity of the polymer can be suppressed.

[0040] The molecular weight distribution (Mw / Mn) of each of the polyoxyalkylene polymers (A1) and (A2) is not particularly limited, but is preferably narrow. Specifically, it is preferably less than 2.0, more preferably 1.6 or less, even more preferably 1.5 or less, and particularly preferably 1.4 or less. From the viewpoint of improving various mechanical properties such as durability and elongation of the cured product, it is preferably 1.2 or less. The molecular weight distribution of the polyoxyalkylene polymers (A1) and (A2) can be determined from the number average molecular weight and weight average molecular weight obtained by GPC measurement.

[0041] The main chain structure of each of the polyoxyalkylene polymers (A1) and (A2) may be linear or branched. However, when the main chain structure of each of the polymers (A1) and (A2) is linear, the cured product elongates more, and therefore, even when the cured film is formed by coating the polymer on a substrate that is susceptible to thermal expansion and contraction, the conformability is improved, which is preferable.

[0042] The ratio of polymer (A1) to polymer (A2) is set within a range of 20:80 to 80:20 by weight. Using both polymers within this ratio range allows for a good balance between roller applicability and strength of the cured product. The ratio is preferably 30:70 to 70:30, and more preferably 40:60 to 60:40.

[0043] The total amount of polymer (A) blended is 12 to 25% by weight, based on 100% by weight of the total amount of the curable composition according to the present disclosure. If the amount of polymer (A) blended is less than 12% by weight, the curability will be insufficient. It is preferably 15% by weight or more, and more preferably 18% by weight or more. On the other hand, if the amount of polymer (A) blended exceeds 25% by weight, the coating film will tend to sag, making it difficult to obtain a cured film with a good appearance. It is preferably 23% by weight or less.

[0044] <Method for synthesizing polyoxyalkylene polymers (A1) and (A2)> Next, the synthesis method of the polyoxyalkylene polymers (A1) and (A2) will be described. As an example of the synthesis method, the polyoxyalkylene polymers (A1) and (A2) can be obtained by introducing a carbon-carbon unsaturated bond into the hydroxyl group terminal of a hydroxyl group-terminated polymer obtained by polymerization, and then reacting the polymer with a hydrolyzable silyl group-containing compound that reacts with the carbon-carbon unsaturated bond. Polymer (A1) can be obtained by introducing two or more carbon-carbon unsaturated bonds into one hydroxyl end of a hydroxyl-terminated polymer, followed by reaction with a hydrolyzable silyl group-containing compound, and polymer (A2) can be obtained by introducing one carbon-carbon unsaturated bond into one hydroxyl end of a hydroxyl-terminated polymer, followed by reaction with a hydrolyzable silyl group-containing compound. These synthesis methods are described below.

[0045] (polymerization) The polymer skeleton of the polyoxyalkylene polymers (A1) and (A2) is preferably formed by a method of polymerizing an epoxy compound with an initiator having a hydroxyl group using a composite metal cyanide complex catalyst such as a zinc hexacyanocobaltate glyme complex.

[0046] Examples of initiators having a hydroxyl group include those having one or more hydroxyl groups, such as ethylene glycol, propylene glycol, glycerin, pentaerythritol, low-molecular-weight polyoxypropylene glycol, polyoxypropylene triol, allyl alcohol, polyoxypropylene monoallyl ether, and polyoxypropylene monoalkyl ether.

[0047] Examples of epoxy compounds include alkylene oxides such as ethylene oxide and propylene oxide, and glycidyl ethers such as methyl glycidyl ether, with propylene oxide being preferred.

[0048] (Introduction of carbon-carbon unsaturated bonds) A preferred method for introducing two or more carbon-carbon unsaturated bonds into one terminal is to react an alkali metal salt with a hydroxyl-terminated polymer, then react with an epoxy compound having a carbon-carbon unsaturated bond, and then react with a halogenated hydrocarbon compound having a carbon-carbon unsaturated bond.A preferred method for introducing one carbon-carbon unsaturated bond into one terminal is to react an alkali metal salt with a hydroxyl-terminated polymer, then react with a halogenated hydrocarbon compound having a carbon-carbon unsaturated bond. By using these methods, it becomes possible to control the molecular weight and molecular weight distribution of the polymer main chain by adjusting the polymerization conditions, and further to introduce reactive groups efficiently and stably.

[0049] As the alkali metal salt, sodium hydroxide, sodium methoxide, sodium ethoxide, potassium hydroxide, potassium methoxide, and potassium ethoxide are preferred, and sodium methoxide and potassium methoxide are more preferred, with sodium methoxide being particularly preferred in terms of availability.

[0050] As the epoxy compound having a carbon-carbon unsaturated bond, in particular, a compound of the general formula (4):

[0051] [ka]

[0052] Compounds represented by the following formula can be preferably used. In formula (4), R 4 represents a divalent bonding group having 1 to 6 carbon atoms, and R 4 R bonded to each carbon atom adjacent to 4 The atoms in R are either carbon, oxygen, or nitrogen. 5 represents hydrogen or a hydrocarbon group having 1 to 10 carbon atoms.

[0053] R 4R may be a divalent organic group having 1 to 6 carbon atoms, or may be a hydrocarbon group which may contain an oxygen atom. The hydrocarbon group preferably has 1 to 4 carbon atoms, more preferably 1 to 3 carbon atoms, and even more preferably 1 or 2 carbon atoms. 4 Specific examples of the group include -CH2OCH2-, -CH2O-, and -CH2-, with -CH2OCH2- being preferred.

[0054] R 5 The hydrocarbon group preferably has 1 to 5 carbon atoms, more preferably 1 to 3 carbon atoms, and even more preferably 1 or 2 carbon atoms. 5 Specific examples of include a hydrogen atom, a methyl group, and an ethyl group, with a hydrogen atom and a methyl group being preferred, and a hydrogen atom being more preferred.

[0055] In a particularly preferred embodiment, the terminal moiety represented by general formula (4) is R 4 is -CH2OCH2- and R 5 is a hydrogen atom.

[0056] As the compound represented by general formula (4), allyl glycidyl ether, methallyl glycidyl ether, glycidyl acrylate, glycidyl methacrylate, butadiene monoxide, and 1,4-cyclopentadiene monoepoxide are preferred in terms of reactivity, with allyl glycidyl ether being particularly preferred.

[0057] The amount of the epoxy compound having a carbon-carbon unsaturated bond added can be any amount, taking into consideration the amount of carbon-carbon unsaturated bonds introduced into the polymer and the reactivity. In particular, the molar ratio of the epoxy compound to the hydroxyl groups in the hydroxyl-terminated polymer is preferably 0.2 or more, more preferably 0.5 or more. Also, the molar ratio is preferably 5.0 or less, more preferably 2.0 or less.

[0058] Examples of halogenated hydrocarbon compounds having a carbon-carbon unsaturated bond include vinyl chloride, allyl chloride, methallyl chloride, vinyl bromide, allyl bromide, methallyl bromide, vinyl iodide, allyl iodide, and methallyl iodide, and it is more preferable to use allyl chloride and methallyl chloride because of their ease of handling.

[0059] The amount of the halogenated hydrocarbon compound having a carbon-carbon unsaturated bond to be added is not particularly limited, but the molar ratio to the hydroxyl groups in the hydroxyl-terminated polymer is preferably 0.7 or more, more preferably 1.0 or more, and is preferably 5.0 or less, more preferably 2.0 or less.

[0060] (Introduction of hydrolyzable silyl groups) The method for introducing the hydrolyzable silyl group is not particularly limited, and known methods can be used. Examples of the introduction method are shown below. (i) A method in which a hydrosilane compound is added to a polymer having a carbon-carbon unsaturated bond by a hydrosilylation reaction. (ii) A method of reacting a polymer having a carbon-carbon unsaturated bond with a compound (also called a silane coupling agent) having both a group capable of reacting with the carbon-carbon unsaturated bond to form a bond and a hydrolyzable silyl group. Examples of the group capable of reacting with the carbon-carbon unsaturated bond to form a bond include, but are not limited to, a mercapto group. (iii) A method of reacting a reactive group-containing polymer with a silane coupling agent. Examples of combinations of reactive groups of the reactive group-containing polymer and the silane coupling agent include, but are not limited to, a hydroxyl group and an isocyanate group, a hydroxyl group and an epoxy group, an amino group and an isocyanate group, an amino group and a thioisocyanate group, an amino group and an epoxy group, an amino group and an α,β-unsaturated carbonyl group (a reaction by Michael addition), a carboxyl group and an epoxy group, and an unsaturated bond and a mercapto group.

[0061] Method (i) is preferred because the reaction is simple, the amount of hydrolyzable silyl groups introduced can be adjusted, and the physical properties of the resulting hydrolyzable silyl group-containing polyoxyalkylene polymer are stable. Methods (ii) and (iii) are preferred because they offer a wide range of reaction options and make it easy to increase the rate of hydrolyzable silyl groups introduced.

[0062] The hydrosilane compound that can be used in method (i) is not particularly limited, but examples thereof include trimethoxysilane, triethoxysilane, tris(2-propenyloxy)silane, triacetoxysilane, dimethoxymethylsilane, diethoxymethylsilane, dimethoxyethylsilane, (chloromethyl)dimethoxysilane, (chloromethyl)diethoxysilane, (methoxymethyl)dimethoxysilane, (methoxymethyl)diethoxysilane, (N,N-diethylaminomethyl)dimethoxysilane, and (N,N-diethylaminomethyl)diethoxysilane.

[0063] The amount of the hydrosilane compound used, expressed as a molar ratio to the carbon-carbon unsaturated bonds in the precursor polymer (number of moles of hydrosilane / number of moles of carbon-carbon unsaturated bonds), is preferably 0.05 to 10 from the viewpoint of reactivity, and more preferably 0.3 to 2 from the viewpoint of economy.

[0064] The hydrosilylation reaction can be accelerated by various catalysts. Examples of known catalysts that can be used include complexes of cobalt, nickel, iridium, platinum, palladium, rhodium, ruthenium, and the like. Examples include platinum supported on alumina, silica, carbon black, and other carriers; chloroplatinic acid; chloroplatinic acid complexes composed of chloroplatinic acid and alcohols, aldehydes, ketones, and the like; platinum-olefin complexes [e.g., Pt(CH=CH)(PPh), Pt(CH=CH)Cl]; platinum-vinylsiloxane complexes [Pt{(vinyl)MeSiOSiMe(vinyl)}, Pt{Me(vinyl)SiO}]; platinum-phosphine complexes [Ph(PPh), Pt(PBu)]; and platinum-phosphite complexes [Pt{P(OPh)}]. From the standpoint of reaction efficiency, it is preferable to use a platinum catalyst such as chloroplatinic acid or a platinum vinylsiloxane complex.

[0065] Examples of silane coupling agents that can be used in the above method (ii) or (iii) include mercaptosilanes that react with unsaturated bonds, such as 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyldimethoxymethylsilane, 3-mercaptopropyltriethoxysilane, mercaptomethyltriethoxysilane, and mercaptomethyldimethoxymethylsilane; and 3-isocyanatepropyltrimethoxysilane, 3-isocyanatepropyldimethoxymethylsilane, 3-isocyanatepropyltriethoxysilane, and isocyanate methyltriethoxysilane that react with hydroxyl groups. isocyanate silanes such as isocyanatemethyltrimethoxysilane, isocyanatemethyltriethoxysilane, isocyanatemethyldimethoxymethylsilane; epoxy silanes such as 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyldimethoxymethylsilane, 3-glycidoxypropyltriethoxysilane, glycidoxymethyltrimethoxysilane, glycidoxymethyltriethoxysilane, glycidoxymethyldimethoxymethylsilane, which react with hydroxyl groups, amino groups, or carboxyl groups; Reacting with alkyl groups, 3-aminopropyltrimethoxysilane, 3-aminopropyldimethoxymethylsilane, 3-aminopropyltriethoxysilane, 3-(2-aminoethyl)propyltrimethoxysilane, 3-(2-aminoethyl)propyldimethoxymethylsilane, 3-(2-aminoethyl)propyltriethoxysilane, 3-(N-ethylamino)-2-methylpropyltrimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-benzoyl aminosilanes such as N-3-aminopropyltrimethoxysilane, N-cyclohexylaminomethyltriethoxysilane, N-cyclohexylaminomethyldiethoxymethylsilane, N-phenylaminomethyltrimethoxysilane, (2-aminoethyl)aminomethyltrimethoxysilane, N,N'-bis[3-(trimethoxysilyl)propyl]ethylenediamine, and bis(3-(trimethoxysilyl)propyl)amine; and hydroxyalkylsilanes such as 3-hydroxypropyltrimethoxysilane and hydroxymethyltriethoxysilane.

[0066] The main chain of each of the polyoxyalkylene polymers (A1) and (A2) may contain an ester bond or a bond represented by the general formula (5): -NR 6 -C(=O)- (5) (In the formula, R 6 represents an organic group having 1 to 10 carbon atoms or a hydrogen atom).

[0067] Cured products obtained from curable compositions containing polyoxyalkylene polymers containing ester bonds or amide segments may have high hardness and strength due to the action of hydrogen bonds, etc. However, polyoxyalkylene polymers containing amide segments, etc. may be cleaved by heat, etc. In addition, curable compositions containing polyoxyalkylene polymers containing amide segments, etc. tend to have high viscosity. In consideration of the above advantages and disadvantages, polyoxyalkylenes containing amide segments, etc., or polyoxyalkylenes not containing amide segments, etc. may be used as the polyoxyalkylene polymers (A1) and (A2).

[0068] Examples of the amide segment represented by the general formula (5) include those formed by a reaction between an isocyanate group and a hydroxyl group, a reaction between an amino group and a carbonate, a reaction between an isocyanate group and an amino group, a reaction between an isocyanate group and a mercapto group, etc. In addition, those formed by a reaction between the amide segment containing an active hydrogen atom and an isocyanate group are also included in the amide segment represented by the general formula (5).

[0069] A method for producing a polyoxyalkylene polymer containing an amide segment includes, for example, reacting a polyoxyalkylene having an active hydrogen-containing group at its terminal with an excess of a polyisocyanate compound to synthesize a polymer having an isocyanate group at its terminal, and then, or simultaneously with the synthesis of the polymer, reacting a polyoxyalkylene polymer containing an isocyanate group at its terminal with a compound of the general formula (6): ZR 7-SiR 3 3-a X a (6) (In the formula, R 3 , X and a are the same as above. 7 is a divalent organic group, preferably a divalent hydrocarbon group having 1 to 20 carbon atoms. Z is a hydroxyl group, a carboxyl group, a mercapto group, a primary amino group, or a secondary amino group. ) can be reacted with all or part of the isocyanate groups of the synthesized polymer.

[0070] The silicon compound represented by the general formula (6) is not particularly limited, and examples thereof include amino group-containing silanes such as γ-aminopropyldimethoxymethylsilane, γ-aminopropyltrimethoxysilane, N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, N-(β-aminoethyl)-γ-aminopropyldimethoxymethylsilane, (N-phenyl)-γ-aminopropyltrimethoxysilane, and N-ethylaminoisobutyltrimethoxysilane; hydroxyl group-containing silanes such as γ-hydroxypropyltrimethoxysilane; and mercapto group-containing silanes such as γ-mercaptopropyltrimethoxysilane and mercaptomethyltriethoxysilane. Furthermore, as described in JP-A-6-211879 (U.S. Patent No. 5,364,955), JP-A-10-53637 (U.S. Patent No. 5,756,751), JP-A-10-204144 (EP0831108), JP-A-2000-169544, and JP-A-2000-169545, Michael addition reaction products of various α,β-unsaturated carbonyl compounds and primary amino group-containing silanes, or Michael addition reaction products of various (meth)acryloyl group-containing silanes and primary amino group-containing compounds can also be used as the silicon compound represented by the general formula (6).

[0071] Further, a method for producing a polyoxyalkylene polymer containing an amide segment can be, for example, a method in which a polyoxyalkylene having an active hydrogen-containing group at its terminal is reacted with a compound of the general formula (7): O=C=NR 7 -SiR 33-a X a (7) (In the formula, R 7 , R 3 , X and a are the same as above.)

[0072] The hydrolyzable silyl group-containing isocyanate compound represented by the general formula (7) is not particularly limited, and examples thereof include γ-trimethoxysilylpropyl isocyanate, γ-triethoxysilylpropyl isocyanate, γ-methyldimethoxysilylpropyl isocyanate, γ-methyldiethoxysilylpropyl isocyanate, γ-(methoxymethyl)dimethoxysilylpropyl isocyanate, trimethoxysilylmethyl isocyanate, triethoxymethylsilylmethyl isocyanate, dimethoxymethylsilylmethyl isocyanate, diethoxymethylsilylmethyl isocyanate, and (methoxymethyl)dimethoxysilylmethyl isocyanate.

[0073] When the polyoxyalkylene polymer contains an amide segment, the number (average value) of amide segments per molecule of the polyoxyalkylene polymer is preferably 1 to 10, more preferably 1.5 to 5, and particularly preferably 2 to 3. In order to reduce the viscosity of the curable composition and improve workability, it is preferable that the polyoxyalkylene polymers (A1) and (A2) do not contain an amide segment.

[0074] <<Plasticizer (B)>> The curable composition according to the present disclosure contains a plasticizer (B). By incorporating the plasticizer (B), the viscosity of the curable composition during roller coating can be reduced, improving roller coatability. Furthermore, the elongation after curing can be increased, improving the ability to follow deformation of the substrate.

[0075] Specific examples of the plasticizer (B) include, but are not limited to, phthalate ester compounds such as dibutyl phthalate, diisononyl phthalate (DINP), diheptyl phthalate, di(2-ethylhexyl) phthalate, diisodecyl phthalate (DIDP), and butyl benzyl phthalate; terephthalate ester compounds such as bis(2-ethylhexyl)-1,4-benzenedicarboxylate; 1,2-cyclohexanedicarboxylic acid diisononyl ester (specifically, Hexamol, a trade name); non-phthalate ester compounds such as dioctyl adipate, dioctyl sebacate, dibutyl sebacate, diisodecyl succinate, and acetyl tributyl citrate; unsaturated fatty acid ester compounds such as butyl oleate and methyl acetylricinoleate; alkylsulfonic acid phenyl esters (specifically, trade name: Mesamoll (manufactured by LANXESS)); phosphate ester compounds; trimellitic acid ester compounds; chlorinated paraffins; hydrocarbon oils such as alkyl diphenyls and partially hydrogenated terphenyls; process oils; epoxidized soybean oil; and epoxy plasticizers such as epoxy benzyl stearate.

[0076] Furthermore, polymer plasticizers can be used. Specific examples of polymer plasticizers include vinyl polymers, polyester plasticizers, polyether polyols such as polyethylene glycol and polypropylene glycol having a number average molecular weight of 500 or more, and polyethers such as derivatives in which the hydroxy groups of these polyether polyols are converted to ester groups, ether groups, etc., polystyrenes, polybutadiene, polybutene, polyisobutylene, butadiene-acrylonitrile, polychloroprene, etc.

[0077] The plasticizer (B) is preferably a cyclic hydrocarbon group-containing dicarboxylic acid ester, which can achieve both roller coatability and resistance to sagging after coating, and can also result in good physical properties for the cured film.

[0078] The cyclic hydrocarbon group may be an aromatic hydrocarbon group or an alicyclic hydrocarbon group, such as a cyclohexane ring.

[0079] Specific examples of the cyclic hydrocarbon group-containing dicarboxylic acid ester include, for alicyclic systems, cyclohexanedicarboxylic acid esters such as 1,2-cyclohexanedicarboxylic acid diisononyl ester (specifically, trade name: Hexamoll DINCH (manufactured by BASF)). For aromatic systems, phthalic acid esters such as dibutyl phthalate, diisononyl phthalate (DINP), diheptyl phthalate, di(2-ethylhexyl) phthalate, diisodecyl phthalate (DIDP), and butyl benzyl phthalate; and terephthalic acid esters such as bis(2-ethylhexyl)-1,4-benzenedicarboxylate.

[0080] The blending amount of plasticizer (B) is 20 to 35 wt % relative to the total amount (100 wt %) of the curable composition according to the present disclosure. If the blending amount of plasticizer (B) is less than 20 wt %, it is difficult to obtain the viscosity-reducing effect of blending component (B), and it is difficult to achieve a viscosity suitable for roller coating. The blending amount is preferably 25 wt % or more, and more preferably 28 wt % or more. On the other hand, if the blending amount of plasticizer (B) exceeds 35 wt %, the coating film tends to sag, making it difficult to obtain a cured film with a good appearance. The blending amount is preferably 32 wt % or less.

[0081] <<Filler (C)>> The curable composition according to the present disclosure contains, as filler (C), kaolin and calcium carbonate having an average particle size of 2.0 to 4.5 μm. The combined use of these two fillers not only improves the strength of the cured film, but also achieves both roller coatability and suppression of sagging after coating. In particular, the use of kaolin improves the strength of the cured product without substantially increasing the viscosity of the curable composition during roller coating.

[0082] Kaolin, also known as kaolinite, is a type of aluminosilicate mineral.

[0083] The calcium carbonate may be either heavy calcium carbonate (natural calcium carbonate) or light calcium carbonate (synthetic calcium carbonate, precipitated calcium carbonate), but heavy calcium carbonate is preferred from the viewpoint of achieving both roller coatability and suppression of sagging of the coating film.Here, heavy calcium carbonate refers to calcium carbonate obtained by pulverizing and classifying limestone.

[0084] Furthermore, the heavy calcium carbonate may be surface-treated heavy calcium carbonate. In this case, the type of surface treatment agent is not particularly limited, but an organic material is preferred, and a fatty acid or a fatty acid ester is particularly preferred. Commercially available products are available as such surface-treated heavy calcium carbonate.

[0085] The calcium carbonate contained in the curable composition according to the present disclosure has an average particle size of 2.0 to 4.5 μm. This allows for both roller applicability and suppression of sagging after application. If the average particle size of calcium carbonate is less than 2.0 μm, the viscosity of the curable composition during roller application may become too high, resulting in poor roller applicability. The average particle size is preferably 2.3 μm or more, and more preferably 2.6 μm or more. Conversely, if the average particle size of calcium carbonate is larger than 4.5 μm, the viscosity of the curable composition after coating will be low, making it difficult to sufficiently suppress sagging.The average particle size of calcium carbonate is preferably 3.9 μm or less, and more preferably 3.5 μm or less. When two or more types of calcium carbonate having different average particle sizes are used, the average particle size of all the calcium carbonates should fall within the range of 2.0 to 4.5 μm. The average particle size referred to in this application is the 50% particle size (median size: D50) in the particle size distribution measured by a laser diffraction particle size measuring device.

[0086] The blending ratio of calcium carbonate to kaolin may be appropriately set in consideration of the effects of the invention, but it is preferable that the blending amount of calcium carbonate is greater than that of kaolin. Specifically, the weight ratio of calcium carbonate to kaolin is preferably 2:1 to 10:1, more preferably 3:1 to 8:1, and even more preferably 4:1 to 6:1.

[0087] The blending amount of filler (C) is 40% by weight or more and 60% by weight or less, based on 100% by weight of the total amount of the curable composition according to the present disclosure. When the blending amount of filler (C) is within this range, the strength-improving effect of the blending of component (C) can be achieved, while the roller coatability of the curable composition can be maintained within a good range. In addition, sagging of the coating film can be easily suppressed. A blending amount of filler (C) within this range is more preferably 45% by weight or more and 55% by weight or less.

[0088] <<Rheology modifier (D)>> The curable composition according to the present disclosure contains a rheology modifier (D). The incorporation of the rheology modifier (D) can prevent sagging of the coating film immediately after application of the curable composition. As a result, the appearance of the cured film obtained by curing the coating film is improved, and it is possible to form a cured film with uniform physical properties.

[0089] The rheology modifier (D) is not particularly limited, and examples thereof include polyamide-based rheology modifiers; hydrogenated castor oil derivatives; and metal soaps such as calcium stearate, aluminum stearate, and barium stearate.

[0090] However, from the viewpoints of suppressing sagging of the coating film and roller coating properties, it is preferable to use a polyamide-based rheology control agent. The polyamide-based rheology control agent is sometimes called a polyamide wax or a fatty acid amide.

[0091] Commercially available polyamide rheology modifiers can be used as appropriate, and specific examples include Disparlon (registered trademark) manufactured by Kusumoto Chemicals Co., Ltd., and Crayvallac (registered trademark) SL, Crayvallac (registered trademark) SLX, Crayvallac (registered trademark) SLT, and Crayvallac (registered trademark) SLW manufactured by Arkema S.A. Among these, Crayvallac (registered trademark) SLT is particularly preferred.

[0092] The amount of rheology modifier (D) blended is 0.6 parts by weight or more and 7 parts by weight or less per 100 parts by weight of polymer (A). If the amount of component (D) blended is less than 0.6 parts by weight, the effect of suppressing sagging of the coating film will be insufficient. It is preferably 0.7 parts by weight or more, more preferably 1 part by weight or more, and even more preferably 2 parts by weight or more. On the other hand, if it exceeds 7 parts by weight, the viscosity of the curable composition during roller coating may increase too much, resulting in reduced roller coatability. It is preferably 6 parts by weight or less, more preferably 5 parts by weight or less, and even more preferably 4 parts by weight or less.

[0093] <<Curing catalyst (E)>> The curable composition according to the present disclosure preferably contains a curing catalyst (E) (also referred to as a silanol condensation catalyst) to promote the curing reaction of the curable composition by hydrolysis and condensation of the hydrolyzable silyl groups of the polymer (A).

[0094] Examples of the curing catalyst (E) include organotin compounds, metal carboxylates, amine compounds, carboxylic acids, and alkoxy metals.

[0095] Specific examples of organotin compounds include dibutyltin dilaurate, dibutyltin dioctanoate, dibutyltin bis(butyl maleate), dibutyltin diacetate, dibutyltin oxide, dibutyltin bis(acetylacetonate), dioctyltin bis(acetylacetonate), dioctyltin dilaurate, dioctyltin distearate, dioctyltin diacetate, dioctyltin oxide, a reaction product of dibutyltin oxide with a silicate compound, a reaction product of dioctyltin oxide with a silicate compound, and a reaction product of dibutyltin oxide with a phthalate ester.

[0096] Specific examples of metal carboxylates include tin carboxylate, bismuth carboxylate, titanium carboxylate, zirconium carboxylate, iron carboxylate, potassium carboxylate, calcium carboxylate, etc. The carboxylic acid group can be a combination of the following carboxylic acids with various metals. Specifically, iron 2-ethylhexanoate (divalent), iron 2-ethylhexanoate (trivalent), titanium 2-ethylhexanoate (tetravalent), vanadium 2-ethylhexanoate (trivalent), calcium 2-ethylhexanoate (divalent), potassium 2-ethylhexanoate (monovalent), barium 2-ethylhexanoate (divalent), manganese 2-ethylhexanoate (divalent), nickel 2-ethylhexanoate (divalent), cobalt 2-ethylhexanoate (divalent), zirconium 2-ethylhexanoate (tetravalent), iron neodecanoate (divalent), iron neodecanoate (trivalent), titanium neodecanoate (tetravalent), vanadium neodecanoate (trivalent), calcium neodecanoate (divalent), potassium neodecanoate (monovalent), barium neodecanoate (divalent), di-ethylhexanoate Examples of suitable oleates include zinc (tetravalent), iron oleate (divalent), iron oleate (trivalent), titanium oleate (tetravalent), vanadium oleate (trivalent), calcium oleate (divalent), potassium oleate (monovalent), barium oleate (divalent), manganese oleate (divalent), nickel oleate (divalent), cobalt oleate (divalent), zirconium oleate (tetravalent), iron naphthenate (divalent), iron naphthenate (trivalent), titanium naphthenate (tetravalent), vanadium naphthenate (trivalent), calcium naphthenate (divalent), potassium naphthenate (monovalent), barium naphthenate (divalent), manganese naphthenate (divalent), nickel naphthenate (divalent), cobalt naphthenate (divalent), and zirconium naphthenate (tetravalent).

[0097] 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.

[0098] 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.

[0099] 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).

[0100] In addition, a fluorine anion-containing compound, a photoacid generator, or a photobase generator can also be used as the curing catalyst (E).

[0101] As the curing catalyst (E), one type may be used alone, or two or more different types of catalysts may be used in combination. The amount of the curing catalyst (E) added is preferably 0.001 to 20 parts by weight, more preferably 0.01 to 15 parts by weight, and particularly preferably 0.1 to 10 parts by weight, per 100 parts by weight of the hydrolyzable silyl group-containing polymer (A).

[0102] <<Other ingredients>> In addition to the hydrolyzable silyl group-containing polymer (A), plasticizer (B), filler (C), rheology modifier (D), and curing catalyst (E), additives such as adhesion promoters, antioxidants, light stabilizers, UV absorbers, physical property modifiers, tackifier resins, epoxy group-containing compounds, photocurable substances, oxygen-curable substances, epoxy resins, and other resins may be added to the curable composition according to the present disclosure. Furthermore, various additives may be added to the curable composition according to the present disclosure as needed to adjust the physical properties of the curable composition or the cured product. Examples of such additives include surface modifiers, foaming agents, curability modifiers, flame retardants, silicates, radical inhibitors, metal deactivators, antiozonants, phosphorus-based peroxide decomposers, lubricants, pigments, and mildewcides.

[0103] <Adhesion promoter> The curable composition according to the present disclosure may contain an adhesion promoter. Examples of the adhesion promoter include a silane coupling agent and a reaction product of a silane coupling agent.

[0104] Specific examples of the silane coupling agent include amino group-containing silanes such as γ-aminopropyltrimethoxysilane, γ-aminopropylmethyldimethoxysilane, N-β-aminoethyl-γ-aminopropyltrimethoxysilane, N-β-aminoethyl-γ-aminopropylmethyldimethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, and (2-aminoethyl)aminomethyltrimethoxysilane; γ-isocyanatepropyltrimethoxysilane, γ-isocyanatepropyltriethoxysilane, and γ-isopropyltriethoxysilane. Examples of suitable silanes include isocyanate group-containing silanes such as α-isocyanate propyl methyl dimethoxy silane, α-isocyanate methyl trimethoxy silane, and α-isocyanate methyl dimethoxy methyl silane; mercapto group-containing silanes such as γ-mercapto propyl trimethoxy silane, γ-mercapto propyl triethoxy silane, and γ-mercapto propyl methyl dimethoxy silane; and epoxy group-containing silanes such as γ-glycidoxy propyl trimethoxy silane and β-(3,4-epoxycyclohexyl) ethyl trimethoxy silane.

[0105] Also usable are condensates of various silane coupling agents, such as condensates of aminosilanes and condensates of aminosilanes with other alkoxysilanes; reaction products of aminosilanes and epoxysilanes, reaction products of aminosilanes and (meth)acrylic group-containing silanes, etc. Specific examples include Dynasylan 1146 and Dynasylan 1124 (manufactured by EVONIK).

[0106] The adhesion promoter may be used alone or in combination of two or more kinds. The amount of the silane coupling agent to be added is preferably 0.1 to 20 parts by weight, particularly preferably 0.5 to 10 parts by weight, based on 100 parts by weight of the hydrolyzable silyl group-containing polymer (A).

[0107] <Antioxidants> The curable composition according to the present disclosure may contain an antioxidant (anti-aging agent). The use of an antioxidant can improve the weather resistance of the cured product. Examples of antioxidants include hindered phenols, monophenols, bisphenols, and polyphenols. Examples include BHT, Irganox 245, Irganox 1010, Irganox 1035, Irganox 1076, Irganox 1135, Irganox 1330, Irganox 1520, and SONGNOX 1076. Similarly, hindered amine light stabilizers such as Tinuvin 622LD, Tinuvin 144, and Tinuvin 292; Chimassorb 944LD and Chimassorb 119FL (all manufactured by BASF); Adekastab LA-57, Adekastab LA-62, Adekastab LA-67, Adekastab LA-63, and Adekastab LA-68 (all manufactured by ADEKA Corporation); Sanol LS-2626, Sanol LS-1114, and Sanol LS-744 (all manufactured by Sankyo Lifetech Co., Ltd.); and Nocrac CD (manufactured by Ouchi Shinko Chemical Industry Co., Ltd.) can also be used. Other antioxidants that can be used include SONGNOX4120, Naugard 445, and OKABEST CLX050.

[0108] Specific examples of antioxidants are also described in Japanese Patent Application Laid-Open Nos. 4-283259 and 9-194731.

[0109] The amount of the antioxidant to be added 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 hydrolyzable silyl group-containing polymer (A).

[0110] <Light stabilizer> The curable composition according to the present disclosure may contain a light stabilizer. The incorporation of a light stabilizer can prevent photooxidative degradation of the cured product. Examples of light stabilizers include benzotriazole-based, hindered amine-based, and benzoate-based compounds, with hindered amine-based compounds being particularly preferred.

[0111] 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, and Tinuvin B97; CHIMASSORB119FL and CHIMASSORB944LD (all manufactured by BASF); ADK STAB LA-57, LA-62, LA-63, 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 of light stabilizers include CS944 (both manufactured by SONGWON) and Nocrac CD (manufactured by Ouchi Shinko Chemical Industry Co., Ltd.).

[0112] The amount of the light stabilizer to be added 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 hydrolyzable silyl group-containing polymer (A).

[0113] <UV absorber> The curable composition according to the present disclosure may contain an ultraviolet absorber. Adding an ultraviolet absorber can improve the surface weather resistance of the cured product. Examples of ultraviolet absorbers include benzophenone-based, benzotriazole-based, salicylate-based, triazine-based, substituted acrylonitrile-based, and metal chelate-based compounds, with benzotriazole-based compounds being particularly preferred. Examples 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). Examples of triazine compounds include TINUVIN 400, TINUVIN 405, TINUVIN 477, and TINUVIN 1577ED (all manufactured by BASF), SONGSORB CS400 and SONGSORB 1577 (manufactured by SONGWON), etc. Examples of benzophenone compounds include SONGSORB 8100 (manufactured by SONGWON).

[0114] The amount of the ultraviolet absorber to be added 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 hydrolyzable silyl group-containing polymer (A).

[0115] Addworks IBC760 (manufactured by Clariant) can also be used as a product containing antioxidants, light stabilizers, and UV absorbers.

[0116] <Physical property adjusters> The curable composition according to the present disclosure may contain a physical property modifier that adjusts the tensile properties of the cured product. The physical property modifier is not particularly limited, but examples include alkylalkoxysilanes such as phenoxytrimethylsilane, methyltrimethoxysilane, dimethyldimethoxysilane, trimethylmethoxysilane, and n-propyltrimethoxysilane; arylalkoxysilanes such as diphenyldimethoxysilane and phenyltrimethoxysilane; alkylisopropenoxysilanes such as dimethyldiisopropenoxysilane, methyltriisopropenoxysilane, and γ-glycidoxypropylmethyldiisopropenoxysilane; trialkylsilylborates such as tris(trimethylsilyl)borate and tris(triethylsilyl)borate; silicone varnishes; and polysiloxanes. The use of such a physical property modifier can increase the hardness of the curable composition according to the present disclosure when cured, or conversely, decrease the hardness and increase the elongation at break. The physical property modifiers may be used alone or in combination of two or more.

[0117] 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 form trimethylsilanol are particularly preferred. Examples of compounds that hydrolyze to form a compound having a monovalent silanol group in the molecule include silicon compounds that are derivatives of alcohols such as hexanol, octanol, phenol, trimethylolpropane, glycerin, pentaerythritol, and sorbitol and that form silane monools on hydrolysis. Specific examples include phenoxytrimethylsilane and tris((trimethylsiloxy)methyl)propane.

[0118] The amount of the physical property adjuster to be added is preferably 0.1 to 10 parts by weight, more preferably 0.5 to 5 parts by weight, based on 100 parts by weight of the hydrolyzable silyl group-containing polymer (A).

[0119] <Tackifying resin> The curable composition according to the present disclosure may contain a tackifying resin for the purpose of enhancing adhesion and adhesion to a substrate. The tackifying resin is not particularly limited, and any commonly used resin can be used.

[0120] Specific examples include terpene resins, aromatic modified terpene resins, hydrogenated terpene resins, terpene-phenol resins, phenol resins, modified phenol resins, xylene-phenol resins, cyclopentadiene-phenol resins, coumarone-indene resins, rosin resins, rosin ester resins, hydrogenated rosin ester resins, xylene resins, low-molecular-weight polystyrene resins, styrene copolymer resins, styrene block copolymers and hydrogenated products thereof, petroleum resins (e.g., C5 hydrocarbon resins, C9 hydrocarbon resins, C5C9 hydrocarbon copolymer resins, etc.), hydrogenated petroleum resins, DCPD resins, etc. These may be used alone or in combination of two or more.

[0121] The amount of the tackifier resin to be added 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 hydrolyzable silyl group-containing polymer (A).

[0122] <Compounds containing epoxy groups> The curable composition according to the present disclosure may contain a compound containing an epoxy group. The incorporation 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 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 epoxy compound is preferably incorporated in an amount ranging from 0.5 to 50 parts by weight per 100 parts by weight of the hydrolyzable silyl group-containing polymer (A).

[0123] <Photocurable substance> The curable composition according to the present disclosure can contain a photocurable substance. Adding a photocurable substance forms a film of the photocurable substance on the surface of the cured product, improving the stickiness and weather resistance of the cured product. Many compounds of this type are known, including organic monomers, oligomers, resins, and compositions containing them. Representative examples include unsaturated acrylic compounds, which are monomers, oligomers, or mixtures thereof, having one or more acrylic or methacrylic unsaturated groups, polyvinyl cinnamates, and azido resins.

[0124] The amount of the photocurable substance to be added 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 hydrolyzable silyl group-containing polymer (A).

[0125] <Oxygen curing substance> The curable composition according to the present disclosure can contain an oxygen-curable substance. Examples of oxygen-curable substances include unsaturated compounds that can react with oxygen in the air to form a cured film near the surface of the cured product, thereby preventing surface stickiness and preventing the adhesion of dirt and dust to the cured product surface. Specific examples of oxygen-curable substances include drying oils such as tung oil and linseed oil, and various alkyd resins obtained by modifying such compounds; acrylic polymers, epoxy resins, and silicone resins modified with drying oils; and liquid polymers such as 1,2-polybutadiene, 1,4-polybutadiene, and polymers of C5-C8 dienes obtained by polymerizing or copolymerizing diene compounds such as butadiene, chloroprene, isoprene, and 1,3-pentadiene. These substances may be used alone or in combination of two or more.

[0126] The amount of the oxygen-curable substance to be added 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 hydrolyzable silyl group-containing polymer (A). As described in JP-A-3-160053, the oxygen-curable substance is preferably used in combination with a photocurable substance.

[0127] <Epoxy resin> The curable composition according to the present disclosure can be used in combination with an epoxy resin, such as bisphenol A epoxy resins or novolac epoxy resins.

[0128] The ratio by weight of these epoxy resins to the hydrolyzable silyl group-containing polymer (A) is preferably in the range of (A) / epoxy resin=100 / 1 to 1 / 100.

[0129] When an epoxy resin is blended, it is preferable to blend a curing agent that cures the epoxy resin in the curable composition according to the present disclosure. There are no particular limitations on the epoxy resin curing agent that can be used, and commonly used epoxy resin curing agents can be used.

[0130] When an epoxy resin curing agent is added, the amount added is preferably in the range of 0.1 to 300 parts by weight per 100 parts by weight of the epoxy resin.

[0131] <<Viscosity of the curable composition>> The curable composition according to the present disclosure preferably has a low viscosity when applied using a roller. Therefore, it is preferable that the viscosity measured at a high rotation speed is low. Specifically, the viscosity measured at a temperature of 23°C and 100 rpm is preferably 10 Pa·s or less, more preferably 8 Pa·s or less. The lower limit is not particularly limited, but may be, for example, 1 Pa·s or more, preferably 3 Pa·s or more, and more preferably 5 Pa·s or more.

[0132] On the other hand, the curable composition according to the present disclosure has the property of being less likely to drip after application. Therefore, it is preferable that the viscosity measured at a low rotation speed is high. Specifically, the viscosity of the curable composition measured at a temperature of 23°C and 2 rpm is preferably 45 Pa·s or more, more preferably 50 Pa·s or more, even more preferably 60 Pa·s or more, and particularly preferably 70 Pa·s or more. The upper limit is not particularly limited, but may be, for example, 100 Pa·s or less, preferably 90 Pa·s or less, and more preferably 80 Pa·s or less.

[0133] <<Preparation of Curable Composition>> The curable composition according to the present disclosure 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. Alternatively, it can be prepared as a two-component composition in which ingredients such as a curing catalyst, a filler, a plasticizer, and water are mixed separately as a curing agent, and a composition containing the ingredients and the polymer (A) is mixed before use. From the viewpoint of workability, the one-component composition is preferred.

[0134] When the curable composition is a one-component type, all of the components are blended in advance, and therefore it is preferable to dehydrate and dry the components containing water before use, or to dehydrate them by reducing the pressure during blending and kneading. In addition to the dehydration and drying method, the storage stability can be further improved by adding an alkoxysilane compound such as n-propyltrimethoxysilane, vinyltrimethoxysilane, phenyltrimethoxysilane, vinylmethyldimethoxysilane, γ-mercaptopropylmethyldimethoxysilane, γ-mercaptopropylmethyldiethoxysilane, or γ-glycidoxypropyltrimethoxysilane as a dehydrating agent.

[0135] The amount of the dehydrating agent, particularly a silicon compound capable of reacting with water such as vinyltrimethoxysilane, 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 hydrolyzable silyl group-containing polymer (A).

[0136] <<Applications of curable compositions>> The curable composition according to the present disclosure is applied to a substrate surface using a roller, and then cured to form a cured film. The roller is not particularly limited, and may be a known roller such as a hand-held roller. Specific examples include the Woo Roller series manufactured by Otsuka Brush Manufacturing Co., Ltd.

[0137] The substrate to which the curable composition according to the present disclosure is applied is not particularly limited, and examples include the exterior walls, roofs, and rooftops of buildings. In particular, it can be used to form a film that seamlessly covers the entire exterior wall material. Such a film can function as a waterproof film. That is, the curable composition according to the present disclosure can be used to form a waterproof film on the surface of a substrate by coating with a roller. Since a cured product of the hydrolyzable silyl group-containing polymer (A) generally exhibits moisture permeability, the waterproof film can function as a moisture-permeable waterproof film. It should be noted that the use as a waterproof membrane described here is different from the use as a sealant for filling gaps and joints in substrates.

[0138] The material constituting the substrate is not particularly limited, but examples thereof include porous materials such as siding boards, concrete, CMU backup walls, mortar, stone, and metal.

[0139] The conditions for curing the coating film are not particularly limited, and for example, after coating, the coating film may be left at room temperature for about 1 to 5 days.

[0140] The thickness of the cured film formed on the surface of the substrate is not particularly limited, but may be, for example, within a range of about 0.3 mm to 3 mm, preferably about 0.7 mm to 2.5 mm, and more preferably about 1 mm to 2 mm.

[0141] Cured products formed from the curable compositions according to the present disclosure have high strength and elongation. Specifically, the tensile strength of the cured products measured at 23°C can be 1 MPa or more, and the tensile elongation of the cured products measured at 23°C can be 300% or more. The tensile strength may be 1.2 MPa or more, and the tensile elongation may be 350% or more, or even 400% or more. These tensile strengths and tensile elongations are values ​​measured under the conditions described in the Examples section.

[0142] The following items list preferred aspects of the present disclosure, but the present invention is not limited to the following items. [Item 1] A curable composition comprising a polymer (A) having a hydrolyzable silyl group, a plasticizer (B), a filler (C), a rheology modifier (D), and a curing catalyst (E), the polymer (A) comprises a polyoxyalkylene polymer (A1) having more than one hydrolyzable silyl group on average at one terminal site, and a polyoxyalkylene polymer (A2) having one or less hydrolyzable silyl group on average at one terminal site, and the ratio of the content of (A1) to the content of (A2) is 20:80 to 80:20 by weight; The filler (C) contains kaolin and calcium carbonate having an average particle size of 2.0 to 4.5 μm, the content of the polymer (A) is 12 to 25% by weight, the content of the plasticizer (B) is 20 to 35% by weight, and the content of the filler (C) is 40 to 60% by weight, based on the total weight of the curable composition; The curable composition, wherein the content of the rheology modifier (D) is 0.6 to 7 parts by weight based on 100 parts by weight of the polymer (A). [Item 2] Item 1. The curable composition according to item 1, wherein the viscosity of the curable composition measured at 23°C and 2 rpm is 45 Pa s or more and the viscosity of the curable composition measured at 23°C and 100 rpm is 10 Pa s or less. [Item 3] 3. The curable composition according to item 1 or 2, wherein the tensile strength of the cured product obtained by curing the curable composition, measured at 23°C, is 1 MPa or more, and the tensile elongation of the cured product obtained by curing the curable composition, measured at 23°C, is 300% or more. [Item 4] 4. The curable composition according to any one of items 1 to 3, wherein the rheology modifier (D) is a polyamide-based rheology modifier. [Item 5] 5. The curable composition according to any one of items 1 to 4, wherein the plasticizer (B) is a cyclic hydrocarbon group-containing dicarboxylic acid ester. [Item 6] 6. A method for producing a cured film, comprising the steps of applying the curable composition according to any one of items 1 to 5 by roller coating and curing the composition. [Item 7] Item 7. The method according to item 6, wherein the cured membrane is a waterproof membrane. [Example]

[0143] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0144] (number average molecular weight) The number average molecular weight in the examples is a GPC molecular weight measured under the following conditions. Liquid delivery system: Tosoh HLC-8220GPC Column: Tosoh TSKgel SuperH series Solvent: THF Molecular weight: Polystyrene equivalent Measurement temperature: 40℃

[0145] The end group-based molecular weight in the examples is a molecular weight calculated by determining the hydroxyl value according to the measurement method of JIS K 1557 and the iodine value according to the measurement method of JIS K 0070, taking into consideration the structure of the organic polymer (the degree of branching determined by the polymerization initiator used).

[0146] The average number of silyl groups introduced per terminal or per molecule of the polymers shown in the examples was calculated by NMR measurement.

[0147] (Synthesis Example 1) Polymer (A1-1) Using polyoxypropylene glycol with a number-average molecular weight of approximately 4,500 as an initiator, propylene oxide was polymerized in the presence of a zinc hexacyanocobaltate glyme complex catalyst to obtain polyoxypropylene (P-1) with a number-average molecular weight of 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, 1.0 molar equivalent of sodium methoxide was added as a 28% methanol solution relative to the hydroxyl groups of the hydroxyl-terminated polyoxypropylene (P-1). After removing the methanol by vacuum devolatilization, 1.0 molar equivalent of allyl glycidyl ether relative to the hydroxyl groups of the polymer (P-1) was added and the reaction was carried out at 130°C for 2 hours. Subsequently, 0.28 molar equivalent of sodium methoxide in methanol was added to remove the methanol, and 1.79 molar equivalent of allyl chloride was added to convert the terminal hydroxyl groups to allyl groups. The resulting crude polyoxypropylene was mixed with n-hexane and water and stirred, then centrifuged to remove the water. The resulting hexane solution was then devolatilized under reduced pressure to remove the metal salts in the polymer. This yielded polyoxypropylene (Q-1) with multiple carbon-carbon unsaturated bonds at its terminals. It was found that polymer (Q-1) had an average of 2.0 carbon-carbon unsaturated bonds at each terminal. To 500 g of the resulting (Q-1), 50 μL of platinum divinyldisiloxane complex solution (3 wt. % platinum equivalent isopropanol solution) was added, and 9.6 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 yield polyoxypropylene (A1-1) with a number-average molecular weight of 28,500 and multiple dimethoxymethylsilyl groups at its terminals. It was found that polymer (A1-1) contained an average of 1.7 dimethoxymethylsilyl groups at each terminal, with an average of 3.4 per molecule.

[0148] (Synthesis example 2) Polymer (A2-1) Using polyoxypropylene glycol with a number-average molecular weight of approximately 4,500 as an initiator, propylene oxide was polymerized with a zinc hexacyanocobaltate glyme complex catalyst to obtain polyoxypropylene (P-2) with a number-average molecular weight of 14,300 (9,132 molecular weight calculated as end groups) and a molecular weight distribution (Mw / Mn) of 1.21, bearing hydroxyl groups at both ends. To the resulting hydroxyl-terminated polyoxypropylene (P-2), 1.2 molar equivalents of sodium methoxide were added 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-2) to convert the terminal hydroxyl groups to allyl groups. Unreacted allyl chloride was removed by vacuum devolatilization. The resulting unpurified polyoxypropylene was mixed with n-hexane and water, stirred, and then centrifuged to remove the water. 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-2) with allyl groups at the termini. 500 g of this polymer (Q-2) was mixed with 50 μL of a platinum divinyldisiloxane complex solution (a 3 wt. % platinum equivalent isopropanol solution), and 8.4 g of dimethoxymethylsilane was slowly added dropwise while stirring. After reacting for 2 hours at 100°C, unreacted dimethoxymethylsilane was removed under reduced pressure to produce polyoxypropylene (A2-1) with a number-average molecular weight of 14,600 and dimethoxymethylsilyl groups at the termini. It was found that polymer (A2-1) contained an average of 0.8 dimethoxymethylsilyl groups at each terminus, with an average of 1.5 per molecule.

[0149] (Examples 1 to 6, Comparative Examples 1 to 7) According to the compositions (weight ratios) shown in Table 1, polymer (A1-1) and polymer (A2-1) were first mixed with plasticizer (B), filler (C) (calcium carbonate and kaolin), colorant, rheology modifier (D), and antioxidant, and the mixture was stirred using a planetary centrifugal stirring / defoaming mixer (manufactured by Samsung Industries Co., Ltd., trade name: Hi-Rotor HR005-04V). After the mixture was cooled to below 50°C, A-171 (vinyltrimethoxysilane, manufactured by Momentive Performance Materials Holdings Inc.) as a dehydrating agent, A-1120 (N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, manufactured by Momentive Performance Materials Holdings Inc.) as an adhesion promoter, and Neostan U-303 (Nitto Kasei Co., Ltd.: a reaction product of dibutyltin salt and a silicon compound) as a curing catalyst (E) were added in that order, and the mixture was thoroughly mixed with a spatula. After that, the mixture was stirred and defoamed using a planetary centrifugal stirring and defoaming mixer to obtain a curable composition.

[0150] The following raw materials were used in each example and comparative example. Omyacarb 1T-JI (Omya: heavy calcium carbonate, average particle size (D50): 1.8 μm) Omyacarb 2T-JI (Omya: heavy calcium carbonate, average particle size (D50): 2.8 μm) Omyacarb 5T-JI (Omya: heavy calcium carbonate, average particle size (D50): 4.9 μm) CMP-1 (China Gao Ling Earth Co., Ltd.: Calcined kaolin, specific surface area 255 m 2 / g) SLT (Crayvallac SLT, ARKEMA: polyamide-based rheology modifier) DINP (J-Plus Corporation: Diisononyl phthalate) HIBLACK30 (Orion Engineered Carbons: Carbon Black) Irganox 245 (BASF Japan: hindered phenolic antioxidant)

[0151] (BS type viscosity) Each curable composition was filled into a 100 mL cup, taking care to avoid bubbles. Using a BS-type viscometer (Tokyo Keiki Co., Ltd.) and a rotor appropriate for each viscosity, the viscosity was measured at 1 rpm to 100 rpm under conditions of 23°C and 50% RH. The viscosities at 2 rpm and 100 rpm are shown in Table 1.

[0152] (Tensile test) Each curable composition was filled into a polyethylene mold to a thickness of 2 mm, taking care to avoid air bubbles, and then cured for 7 days at 23°C and 50% RH. No. 3 dumbbell-shaped test specimens were punched out from the resulting 2 mm-thick cured product sheets. Using these test specimens, a tensile test (tensile speed 200 mm / min) was conducted at 23°C (50% RH) to measure the strength at break (tensile strength) and elongation at break (tensile elongation). The results are shown in Table 1.

[0153] (Roller workability and resistance to sagging after roller work) In an atmosphere of 23°C and 50% RH, each curable composition was applied to a 30 cm square surface of a wooden plywood board placed on the floor in an amount of approximately 3 kg / m 2 A roller (size 4 inch, bristle length 11 mm: manufactured by Otsuka Brush Manufacturing Co., Ltd., product name: Urethane-kun Small Roller) was used to paint the surface by rolling the roller back and forth over a length of 30 cm, and the number of times the roller was moved back and forth to paint the entire surface was evaluated as roller workability, which is shown in Table 1. A value of 10 times or less was considered to be acceptable. In addition, plywood boards that had been painted to various thicknesses were placed upright, and the maximum film thickness at which the painted surface did not sag was evaluated as sagging resistance, which is shown in Table 1. A value of 1.5 mm or more was considered to be acceptable.

[0154] (Sag resistance measured by sag meter) Each curable composition was applied to a polycarbonate plate at 23°C and 50%RH using a sagmeter (BYK: 14, 16, 18, 20, 25, 30, 35, 40, 45, 50, 60 mils). The polycarbonate plate was then immediately placed vertically, and the maximum film thickness at which each curable composition did not sag was recorded. The film thickness was converted to mm using a value of 0.0254 mm / mil, and the values ​​rounded to two decimal places are shown in Table 1.

[0155] [Table 1]

[0156] As shown in Table 1, Examples 1 to 6 had a large maximum film thickness without sagging and good sagging resistance. Furthermore, the number of roller reciprocating movements required for coating was small, and roller workability was good. The breaking strength and breaking elongation of the cured sheets were also good. On the other hand, Comparative Example 1 did not contain the rheology modifier (D), had a low viscosity at 2 rpm, a small maximum film thickness without sagging, and was insufficient in sagging resistance. In Comparative Example 2, polymer (A2) was not blended, and the viscosity at 100 rpm was high, which increased the number of reciprocating roller strokes required for coating, resulting in insufficient roller workability. In Comparative Example 3, the polymer (A1) was not blended, and the strength after curing was reduced. In Comparative Example 4, the average particle size of calcium carbonate was smaller than 2.0 μm, the viscosity at 100 rpm was high, the number of reciprocating roller movements required for coating was large, and the roller workability was insufficient. In Comparative Example 5, the average particle size of calcium carbonate was larger than 4.5 μm, the viscosity at 2 rpm was low, the maximum film thickness without sagging was small, and the sagging resistance was insufficient. In Comparative Example 6, the content of plasticizer (B) was less than 20% by weight and the content of filler (C) was more than 60% by weight, resulting in reduced elongation after curing and a high viscosity at 100 rpm, which increased the number of roller reciprocating movements required for coating, resulting in insufficient roller workability. In Comparative Example 7, the content of plasticizer (B) was more than 35% by weight and the content of filler (C) was less than 40% by weight, resulting in reduced strength after curing, low viscosity at 2 rpm, a small maximum film thickness without sagging, and insufficient sagging resistance.

[0157] Next, to confirm that the curable composition of Example 2 is excellent in roller workability and sagging resistance, it was compared with five curable compositions containing commercially available hydrolyzable silyl group-containing polymers (MS polymer, silylated polyurethane, polyurethane, or water-based acrylic) as the main component. BS viscosity and tensile test evaluations were performed in the same manner as above.

[0158] (Comparison of roller workability and sagging resistance after roller work with existing products) At a temperature of 20°C and a humidity of approximately 60% outdoors, each curable composition was applied to the surface of a concrete block 19 cm wide and 39 cm high placed on the floor in an amount of approximately 3 kg / m 2 A roller (size 4 inch, bristle length 11 mm: manufactured by Otsuka Brush Manufacturing Co., Ltd., product name: Urethane-kun Small Roller) was used to apply the paint by rolling the roller up and down over a length of 39 cm, and the number of times the roller was moved back and forth to coat the entire surface was evaluated as roller workability, which is shown in Table 2. In addition, paint was applied to various thicknesses, and the maximum film thickness at which the coated surface did not sag was evaluated as sagging resistance.

[0159] [Table 2]

[0160] Table 2 shows that the curable composition of Example 2 has the advantage of being able to increase the maximum film thickness at which the coated surface does not sag, compared with the paints of Reference Examples 2 to 5, which contain silylated polyurethane, polyurethane, or water-based acrylic as the main component. Furthermore, it is clear that the curable composition of Example 2 is an excellent paint, with high film strength and elongation, despite having a low viscosity at 100 rpm and excellent coatability, compared with the paint of Reference Example 1, which contains an MS polymer as the main component. The number of roller reciprocation times for Example 2 in Table 2 is greater than that for Example 2 in Table 1. This is because the coating was applied to a horizontal surface in the evaluation of Table 1, whereas the coating was applied to a vertical surface in the evaluation of Table 2, making it more difficult to apply.

Claims

1. A curable composition comprising a polymer (A) having a hydrolyzable silyl group, a plasticizer (B), a filler (C), a rheology modifier (D), and a curing catalyst (E), the polymer (A) comprises a polyoxyalkylene polymer (A1) having more than one hydrolyzable silyl group on average at one terminal site, and a polyoxyalkylene polymer (A2) having one or less hydrolyzable silyl group on average at one terminal site, and the ratio of the content of (A1) to the content of (A2) is 20:80 to 80:20 by weight; The filler (C) contains kaolin and calcium carbonate having an average particle size of 2.0 to 4.5 μm, the content of the polymer (A) is 12 to 25% by weight, the content of the plasticizer (B) is 20 to 35% by weight, and the content of the filler (C) is 40 to 60% by weight, based on the total weight of the curable composition; The content of the rheology modifier (D) is 0.6 to 7 parts by weight based on 100 parts by weight of the polymer (A).

2. 2. The curable composition according to claim 1, wherein the viscosity of the curable composition measured at 23°C and 2 rpm is 45 Pa s or more and the viscosity of the curable composition measured at 23°C and 100 rpm is 10 Pa s or less.

3. 2. The curable composition according to claim 1, wherein the cured product obtained by curing the curable composition has a tensile strength of 1 MPa or more, measured at 23°C, and a tensile elongation of 300% or more, measured at 23°C.

4. The curable composition according to any one of claims 1 to 3, wherein the rheology modifier (D) is a polyamide-based rheology modifier.

5. The curable composition according to any one of claims 1 to 3, wherein the plasticizer (B) is a cyclic hydrocarbon group-containing dicarboxylic acid ester.

6. A method for producing a cured film, comprising the steps of: applying the curable composition according to any one of claims 1 to 3 by roller coating; and curing the composition.

7. The method of claim 6, wherein the cured film is a waterproof film.

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