Hardening components

Abstract

To provide a curable composition that exhibits excellent stain resistance and can maintain excellent rubber elasticity over a long period of time after curing.SOLUTION: A curable composition of the present invention is characterized in containing (I) an organic polymer having a hydrolyzable silyl group, (B) a (meth)acrylic acid ester-based polymer containing a polyoxyethylene chain-containing (meth)acrylic acid ester unit, (C) a fluoroalkyl compound, and (D) a silanol condensation catalyst. Thus, by using (B) (meth)acrylic acid ester-based polymer and (C) fluoroalkyl compound in combination, a curable composition that can exhibit excellent stain resistance and can maintain excellent rubber elasticity over a long period of time after curing can be provided.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a curable composition that cures with moisture in the atmosphere (air) to give a cured product that exhibits excellent stain resistance and is capable of maintaining excellent rubber elasticity for an extended period of time. [Background technology]

[0002] Conventionally, curable compositions containing oxyalkylene polymers having crosslinkable hydrolyzable silyl groups have been known (for example, Patent Document 1). The crosslinkable hydrolyzable silyl groups in the curable compositions are hydrolyzed by moisture in the atmosphere, followed by dehydration condensation, to produce cured products with excellent adhesiveness.

[0003] As a curable composition, Patent Document 2 discloses a moisture-curable composition characterized by containing an organic carboxylate or an organic amine in an alkoxysilyl group-containing polyoxyalkylene polymer.

[0004] Such curable compositions are used, for example, in the exterior walls of building structures, to join exterior wall members such as mortar boards, concrete boards, ALC (Autoclaved Lightweight Concrete) boards, metal boards, etc. by filling the joints (so-called "joints") between these exterior wall members. By using the curable composition in this way, rainwater is prevented from seeping into the interior of the building structure through the joints between the exterior wall members.

[0005] In the exterior walls of building structures, the joint width changes slightly as exterior wall components expand or contract with temperature changes, or as exterior wall components move due to vibrations or external forces caused by earthquakes or strong winds. Therefore, it is necessary for the curable composition to have excellent rubber elasticity after curing and be able to expand and contract so that it can firmly adhere to the exterior wall and follow changes in joint width. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent No. 5698422 [Patent Document 2] Patent No. 3212370 Summary of the Invention [Problem to be solved by the invention]

[0007] However, there has been a problem in that contaminants such as dust and sand adhere to the surface of a cured product of the curable composition over time, damaging the appearance. Furthermore, contaminants can also cause rain streak stains to form on the surface of a cured product of the curable composition. Rain streak stains are streak-like marks formed when contaminants such as dust and sand that have adhered to the surface of a cured product of the curable composition run down the surface of the cured product along with rainwater. The occurrence of such rain streak stains also damages the appearance of the surface of a cured product of the curable composition. Therefore, curable compositions are required to have excellent stain resistance so that they can maintain a beautiful appearance by reducing the adhesion of contaminants and the occurrence of rain streak stains after curing.

[0008] The present inventors have found that the use of a fluoroalkyl compound can impart excellent stain resistance to the cured product of the curable composition. Based on this finding, the present inventors have conducted further research and found that the use of a fluoroalkyl compound reduces the durability of the cured product of the curable composition. When the durability of the cured product of the curable composition decreases, the rubber elasticity of the cured product of the curable composition decreases over time due to contact of the cured product with moisture in the air or water such as rainwater, making it difficult for the cured product to expand and contract in response to changes in the joint width between exterior wall components. When the rubber elasticity of the cured product of the curable composition decreases in this way, the cured product of the curable composition may peel off from the adhesive interface with the exterior wall component or the exterior wall component may be damaged, resulting in problems such as rainwater seeping into the building structure and causing water leakage.

[0009] Therefore, an object of the present invention is to provide a curable composition that, after curing, exhibits excellent stain resistance and is capable of maintaining excellent rubber elasticity for a long period of time. [Means for solving the problem]

[0010] The curable composition of the present invention is characterized by containing an organic polymer (I) having a hydrolyzable silyl group, a (meth)acrylic acid ester-based polymer (B) containing a (meth)acrylic acid ester unit having a polyoxyethylene chain, a fluoroalkyl compound (C), and a silanol condensation catalyst (D).

[0011] (Organic polymer (I) having hydrolyzable silyl groups) The curable composition of the present invention contains an organic polymer (I) having a hydrolyzable silyl group. In the organic polymer (I) containing the hydrolyzable silyl group, the hydrolyzable group of the hydrolyzable silyl group is hydrolyzed in the presence of water to generate a silanol group (—SiOH). The silanol groups then undergo dehydration condensation with each other to form a crosslinked structure.

[0012] The organic polymer (I) having a hydrolyzable silyl group is not particularly limited, and examples thereof include polyalkylene oxides having a hydrolyzable silyl group, acrylic polymers having a hydrolyzable silyl group, silicone resins having a hydrolyzable silyl group, urethane resins having a hydrolyzable silyl group, and polyolefin resins having a hydrolyzable silyl group. The organic polymer (I) having a hydrolyzable silyl group preferably contains a polyalkylene oxide (A) having a hydrolyzable silyl group. The polyalkylene oxide (A) having a hydrolyzable silyl group can improve the adhesiveness of the curable composition. The organic polymer (I) having a hydrolyzable silyl group preferably does not contain a fluoroalkyl group. The organic polymer (I) having a hydrolyzable silyl group preferably does not contain a (meth)acrylic acid ester unit containing a polyoxyethylene chain. The organic polymer (I) having a hydrolyzable silyl group may be used alone or in combination of two or more.

[0013] The polyalkylene oxide (A) preferably does not have a fluoroalkyl group. Furthermore, the polyalkylene oxide (A) preferably does not contain a (meth)acrylic acid ester unit containing a polyoxyethylene chain. That is, the polyalkylene oxide (A) preferably does not contain a (meth)acrylic acid ester containing a polyoxyethylene chain as a monomer component.

[0014] In the present invention, the hydrolyzable silyl group is a group in which 1 to 3 hydrolyzable groups are bonded to a silicon atom. The hydrolyzable group of the hydrolyzable silyl group is not particularly limited, and examples thereof 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.

[0015] Among these, the hydrolyzable silyl group of the polyalkylene oxide (A) is preferably an alkoxysilyl group because the hydrolysis reaction is mild. Examples of the alkoxysilyl group include trialkoxysilyl groups such as trimethoxysilyl group, triethoxysilyl group, triisopropoxysilyl group, and triphenoxysilyl group; dialkoxysilyl groups such as methyldimethoxysilyl group and methyldiethoxysilyl group; and monoalkoxysilyl groups such as dimethylmethoxysilyl group and dimethylethoxysilyl group. Among these, dialkoxysilyl groups are more preferred, and methyldimethoxysilyl group is particularly preferred.

[0016] The polyalkylene oxide (A) preferably has one to two hydrolyzable silyl groups on average per molecule. When the number of hydrolyzable silyl groups in the polyalkylene oxide (A) is one or more, the curability of the curable composition is improved. When the number of hydrolyzable silyl groups in the polyalkylene oxide (A) is two or less, the mechanical strength or elongation of the cured product of the curable composition is improved. Furthermore, the polyalkylene oxide (A) preferably has a hydrolyzable silyl group at at least one of both ends of its molecular chain.

[0017] The average number of hydrolyzable silyl groups per molecule in the polyalkylene oxide (A) is: 1 It can be calculated based on the concentration of hydrolyzable silyl groups in the polyalkylene oxide (A) determined by H-NMR and the number average molecular weight of the polyalkylene oxide (A) determined by GPC.

[0018] The polyalkylene oxide (A) may be a polyalkylene oxide having a main chain represented by the general formula: -(R 1 -O) n -(In the formula, R 1 represents an alkylene group having 1 to 14 carbon atoms, and n is the number of repeating units and is a positive integer.) The main chain skeleton of the polyalkylene oxide may be composed of only one type of repeating unit, or may be composed of two or more types of repeating units.

[0019] Examples of the main chain skeleton of the polyalkylene oxide (A) include polyethylene oxide, polypropylene oxide, polybutylene oxide, polytetramethylene oxide, polyethylene oxide-polypropylene oxide copolymer, and polypropylene oxide-polybutylene oxide copolymer. Among these, polypropylene oxide is preferred. Polypropylene oxide can provide a curable composition that exhibits excellent rubber elasticity and adhesiveness after curing.

[0020] The number average molecular weight (Mn) of the polyalkylene oxide (A) is preferably 20,000 or more. On the other hand, the number average molecular weight (Mn) of the polyalkylene oxide (A) is preferably 50,000 or less, more preferably 40,000 or less. When the number average molecular weight of the polyalkylene oxide (A) is 20,000 or more, the rubber elasticity of the cured product of the curable composition is improved. When the number average molecular weight of the polyalkylene oxide (A) is 50,000 or less, the coatability of the curable composition is improved.

[0021] The molecular weight distribution (weight average molecular weight (Mw) / number average molecular weight (Mn)) of the polyalkylene oxide (A) is preferably 1.3 or less, more preferably 1.25 or less. On the other hand, the molecular weight distribution (weight average molecular weight (Mw) / number average molecular weight (Mn)) of the polyalkylene oxide (A) is preferably 1.05 or more, more preferably 1.1 or more. When the molecular weight distribution of the polyalkylene oxide (A) is 1.3 or less, the rubber elasticity of the cured product of the curable composition is improved. When the molecular weight distribution of the polyalkylene oxide (A) is 1.05 or more, the workability of the curable composition is improved.

[0022] In the present invention, the number average molecular weight and weight average molecular weight of the polyalkylene oxide refer to values ​​calculated in terms of polystyrene measured by GPC (gel permeation chromatography).

[0023] Specifically, 6 to 7 mg of polyalkylene oxide is collected and placed in a test tube. An ortho-dichlorobenzene (o-DCB) solution containing 0.05% by mass of dibutylhydroxytoluene (BHT) is prepared, added to the test tube, and diluted to a polyalkylene oxide concentration of 1 mg / mL to produce a diluted solution. The diluted solution is shaken using a dissolution and filtration apparatus at 145°C and 25 rpm for 1 hour to dissolve the polyalkylene oxide into the solution, producing a measurement sample. This measurement sample can be used to measure the number-average molecular weight and weight-average molecular weight of the polyalkylene oxide by GPC.

[0024] The number average molecular weight and weight average molecular weight of the polyalkylene oxide can be measured, for example, using the following measuring device and under the following measuring conditions. Measuring device: TOSOH Corporation, product name "HLC-8121GPC / HT" Measurement conditions Column: TSKgelGMHHR-H(20)HT x 3 TSKguardcolumn-HHR(30)HT x 1 Mobile phase: o-DCB 1.0mL / min Sample concentration: 1 mg / mL Detector: Bryce type refractometer Standard material: Polystyrene (TOSOH Corporation, molecular weight: 500-8420000) Elution conditions: 145℃ SEC temperature: 145℃

[0025] The polyalkylene oxide (A) containing a hydrolyzable silyl group can be commercially available. For example, an example of a polyalkylene oxide having a polypropylene oxide main chain skeleton and a methyldimethoxysilyl group at the end of the main chain skeleton is "Excestar ESS4530" manufactured by AGC Inc.

[0026] The content of the polyalkylene oxide (A) having a hydrolyzable silyl group in the organic polymer (I) having a hydrolyzable silyl group is preferably 60% by mass or more, more preferably 70% by mass or more, and particularly preferably 100% by mass. That is, it is particularly preferable that the organic polymer (I) having a hydrolyzable silyl group consists solely of the polyalkylene oxide (A) having a hydrolyzable silyl group. When the content of the polyalkylene oxide (A) having a hydrolyzable silyl group is 60% by mass or more, the adhesiveness of the curable composition can be improved.

[0027] ((Meth)acrylic acid ester polymer (B)) The curable composition contains a (meth)acrylic acid ester polymer (B) containing a (meth)acrylic acid ester unit having a polyoxyethylene chain. By using such a (meth)acrylic acid ester polymer (B) in combination with a fluoroalkyl compound (C) described below, it is possible to provide a curable composition that exhibits excellent stain resistance after curing and can maintain excellent rubber elasticity for a long period of time. It is preferable that the (meth)acrylic acid ester polymer (B) does not contain a fluoroalkyl group.

[0028] The (meth)acrylic acid ester polymer (B) contains a (meth)acrylic acid ester unit containing a polyoxyethylene chain. The main chain skeleton of the (meth)acrylic acid ester polymer (B) is preferably a polymer of an acrylic monomer containing a (meth)acrylic acid ester containing a polyoxyethylene chain.

[0029] It is preferable that the (meth)acrylic acid ester containing a polyoxyethylene chain does not have a hydrolyzable silyl group. Note that (meth)acrylic acid means acrylic acid or methacrylic acid.

[0030] Preferred examples of the (meth)acrylic acid ester containing a polyoxyethylene chain include (meth)acrylic acid esters represented by the following general formula (1).

[0031] [ka] (In the formula, R 2 is a hydrogen atom or a methyl group, and R 3 is a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 24 carbon atoms, a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, or a substituted or unsubstituted aralkyl group having 7 to 20 carbon atoms, and m is an integer of 2 to 100.

[0032] R in Equation (1) 2is preferably a hydrogen atom or a methyl group, more preferably a methyl group.

[0033] In formula (1), m is the number of repeating units and is preferably an integer of 2 or more, more preferably an integer of 3 or more, and particularly preferably an integer of 4 or more. On the other hand, in formula (1), m is preferably an integer of 100 or less, more preferably an integer of 40 or less, more preferably an integer of 30 or less, and particularly preferably an integer of 15 or less.

[0034] R in Equation (1) 3 is preferably a substituted or unsubstituted alkyl group having 1 to 24 carbon atoms, a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, or a substituted or unsubstituted aralkyl group having 7 to 20 carbon atoms.

[0035] R in Equation (1) 3 The substituted or unsubstituted alkyl group having 1 to 24 carbon atoms in the formula (I) may be either linear or branched, and is not particularly limited. Examples of unsubstituted alkyl groups include methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, amyl, isoamyl, tert-amyl, neopentyl, and n-hexyl. The hydrogen atoms of these alkyl groups may be substituted with organic groups such as hydroxyl and alkoxy groups. Aryl groups are preferred from the above organic groups. Examples of substituted alkyl groups include hydroxyalkyl groups and alkoxyalkyl groups. Aralkyl groups such as benzyl are preferred from the substituted alkyl groups.

[0036] R in Equation (1) 3In the substituted or unsubstituted aryl group having 6 to 20 carbon atoms, the aromatic ring constituting the aryl group may be a single ring or a condensed ring. Examples of unsubstituted aryl groups include a phenyl group, a 1-naphthyl group, a 2-naphthyl group, a 1-anthracenyl group, a 2-anthracenyl group, and a 9-anthracenyl group. The hydrogen atoms of these aryl groups may be substituted with organic groups such as a hydroxy group, an alkyl group, and an alkoxy group. Examples of substituted aryl groups include an alkoxyphenyl group and an alkylphenyl group.

[0037] R in Equation (1) 3 Examples of the substituted or unsubstituted aralkyl group having 7 to 20 carbon atoms in the formula (I) include a benzyl group, an α,α-phenylmethylbenzyl group, an α,α-dimethylbenzyl group, an α,α-methylphenylbenzyl group, an α-naphthylmethyl group, a 1-α-naphthylethyl group, a 2-α-naphthylethyl group, a 1-α-naphthylisopropyl group, a 2-α-naphthylisopropyl group, a β-naphthylmethyl group, a 1-β-naphthylethyl group, a 2-β-naphthylethyl group, a 1-β-naphthylisopropyl group, and a 2-β-naphthylisopropyl group.

[0038] R in Equation (1) 3 As the group, a hydrogen atom and a substituted or unsubstituted alkyl group having 1 to 24 carbon atoms are preferred, an unsubstituted alkyl group having 1 to 10 carbon atoms is more preferred, and an unsubstituted alkyl group having 1 to 3 carbon atoms is particularly preferred.

[0039] The alcohol residue forming the (meth)acrylic acid ester containing a polyoxyethylene chain is preferably a polyethylene glycol residue terminally blocked with an alkyl group having 1 to 24 carbon atoms.

[0040] Specific examples of the (meth)acrylic acid ester containing a polyoxyethylene chain include methoxypolyethylene glycol (meth)acrylate, ethoxypolyethylene glycol (meth)acrylate, and propoxypolyethylene glycol (meth)acrylate. Among these, methoxypolyethylene glycol (meth)acrylate is preferred, and methoxypolyethylene glycol methacrylate is more preferred. The (meth)acrylic acid ester containing a polyoxyethylene chain may be used alone or in combination of two or more.

[0041] The content of polyoxyethylene chain-containing (meth)acrylic ester units in the (meth)acrylic ester polymer (B) is preferably 10% by mass or more, more preferably 20% by mass or more, and particularly preferably 25% by mass or more. Meanwhile, the content of polyoxyethylene chain-containing (meth)acrylic ester units in the (meth)acrylic ester polymer (B) is preferably less than 50% by mass, more preferably 45% by mass or less. When the content of polyoxyethylene chain-containing (meth)acrylic ester units is 10% by mass or more, the surface of the cured product of the curable composition can be imparted with good self-cleaning properties with water. When the content of polyoxyethylene chain-containing (meth)acrylic ester units is less than 50% by mass, the durability of the cured product of the curable composition is improved. This can reduce the decrease in rubber elasticity of the cured product of the curable composition due to contact with water.

[0042] The (meth)acrylic acid ester polymer (B) preferably contains a (meth)acrylic acid alkyl ester unit. More preferably, the main chain skeleton of the (meth)acrylic acid ester polymer (B) is a polymer of an acrylic monomer containing a (meth)acrylic acid ester unit containing a polyoxyethylene chain and a (meth)acrylic acid alkyl ester unit. Use of a (meth)acrylic acid alkyl ester improves the durability of the cured product of the curable composition. It is preferable that the (meth)acrylic acid alkyl ester does not contain a polyoxyethylene chain. It is preferable that the (meth)acrylic acid alkyl ester does not have a hydrolyzable silyl group. The hydrogen of the alkyl group of the (meth)acrylic acid alkyl ester is not substituted.

[0043] Examples of the (meth)acrylic acid alkyl ester include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, n-pentyl (meth)acrylate, n-hexyl (meth)acrylate, cyclohexyl (meth)acrylate, n-heptyl (meth)acrylate, n-octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, nonyl (meth)acrylate, decyl (meth)acrylate, dodecyl (meth)acrylate, and stearyl (meth)acrylate. Among these, methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, n-butyl (meth)acrylate, n-pentyl (meth)acrylate, and n-hexyl (meth)acrylate are preferred, methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, and n-butyl (meth)acrylate are more preferred, and n-butyl (meth)acrylate is particularly preferred. The (meth)acrylic acid alkyl esters may be used alone or in combination of two or more.

[0044] The content of (meth)acrylic acid alkyl ester units in the (meth)acrylic acid ester-based polymer (B) is preferably 30% by mass or more, more preferably 50% by mass or more. On the other hand, the content of (meth)acrylic acid alkyl ester units in the (meth)acrylic acid ester-based polymer (B) is preferably 90% by mass or less, more preferably 80% by mass or less. When the content of (meth)acrylic acid alkyl ester units is 30% by mass or more, the durability of the cured product of the curable composition is improved. When the content of (meth)acrylic acid alkyl ester units is less than 90% by mass, the workability of the curable composition is improved.

[0045] The (meth)acrylic acid ester polymer (B) preferably has a hydrolyzable silyl group. The (meth)acrylic acid ester polymer (B) having a hydrolyzable silyl group allows the cured product of the curable composition to maintain excellent rubber elasticity for a long period of time.

[0046] The hydrolyzable silyl group of the (meth)acrylic acid ester polymer (B) is preferably an alkoxysilyl group, since the cured product of the curable composition can maintain excellent rubber elasticity for a long period of time. Examples of the alkoxysilyl group include trialkoxysilyl groups such as trimethoxysilyl, triethoxysilyl, triisopropoxysilyl, and triphenoxysilyl; dimethoxysilyl groups such as methyldimethoxysilyl and methyldiethoxysilyl; and monoalkoxysilyl groups such as dimethylmethoxysilyl and dimethylethoxysilyl. Among these, dialkoxysilyl and trialkoxysilyl groups are more preferred, trialkoxysilyl groups are more preferred, and trimethoxysilyl groups are particularly preferred.

[0047] The (meth)acrylic acid ester polymer (B) preferably contains a (meth)acrylic acid ester unit containing a hydrolyzable silyl group. The main chain skeleton of the (meth)acrylic acid ester polymer (B) is more preferably a polymer of an acrylic monomer containing a (meth)acrylic acid ester containing a polyoxyethylene chain and a (meth)acrylic acid ester containing a hydrolyzable silyl group, and even more preferably a polymer of an acrylic monomer containing a (meth)acrylic acid ester containing a polyoxyethylene chain, a (meth)acrylic acid alkyl ester, and a (meth)acrylic acid ester containing a hydrolyzable silyl group.

[0048] The (meth)acrylic acid ester containing a hydrolyzable silyl group is not particularly limited, and examples thereof include 3-(trimethoxysilyl)propyl (meth)acrylate, 3-(triethoxysilyl)propyl (meth)acrylate, 3-(methyldimethoxysilyl)propyl (meth)acrylate, 2-(trimethoxysilyl)ethyl (meth)acrylate, 2-(triethoxysilyl)ethyl (meth)acrylate, 2-(methyldimethoxysilyl)ethyl (meth)acrylate, trimethoxysilylmethyl (meth)acrylate, triethoxysilylmethyl (meth)acrylate, and (methyldimethoxysilyl)methyl (meth)acrylate. Among these, 3-(trimethoxysilyl)propyl (meth)acrylate and 3-(methyldimethoxysilyl)propyl (meth)acrylate are preferred, 3-(trimethoxysilyl)propyl (meth)acrylate is more preferred, and 3-(trimethoxysilyl)propyl methacrylate is particularly preferred. The (meth)acrylic acid esters containing a hydrolyzable silyl group may be used alone or in combination of two or more. An ester in which the hydrogen of the alkyl group of a (meth)acrylic acid alkyl ester is substituted with a hydrolyzable silyl group is not included in the category of a (meth)acrylic acid alkyl ester, since the hydrogen of the alkyl group is substituted with another atomic group.

[0049] The content of (meth)acrylic acid ester units containing a hydrolyzable silyl group in the (meth)acrylic acid ester polymer (B) is preferably 0.5% by mass or more, more preferably 1% by mass or more. On the other hand, the content of (meth)acrylic acid ester units containing a hydrolyzable silyl group in the (meth)acrylic acid ester polymer (B) is preferably 10% by mass or less, more preferably 7% by mass or less. When the content of (meth)acrylic acid ester units containing a hydrolyzable silyl group is 0.5% by mass or more, the durability of the cured product of the curable composition is improved. This can reduce the decrease in rubber elasticity of the cured product of the curable composition due to contact with water. When the content of (meth)acrylic acid ester units containing a hydrolyzable silyl group is 10% by mass or less, the rubber elasticity of the cured product of the curable composition is improved.

[0050] The (meth)acrylic acid ester polymer (B) may contain a (meth)acrylic acid substituted alkyl ester unit. The (meth)acrylic acid substituted alkyl ester refers to a compound in which a hydrogen atom of the alkyl group of a (meth)acrylic acid alkyl ester is substituted with an organic group such as an alkoxy group, a hydroxy group, a halogen atom (such as a fluorine atom or a chlorine atom), a fluoroalkyl group, or an amino group.

[0051] Examples of the (meth)acrylic acid substituted alkyl ester include 2-methoxyethyl (meth)acrylate, 3-methoxybutyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2,2,2-trifluoroethyl (meth)acrylate, 3,3,3-trifluoropropyl (meth)acrylate, 3,3,4,4,4-pentafluorobutyl (meth)acrylate, 2-perfluoroethyl-2-perfluorobutylethyl (meth)acrylate, trifluoromethyl (meth)acrylate, perfluoroethyl (meth)acrylate, bis(trifluoromethyl)methyl (meth)acrylate, 2-trifluoromethyl-2-perfluoroethylethyl (meth)acrylate, 2-perfluorohexylethyl (meth)acrylate, 2-perfluorodecylethyl (meth)acrylate, 2-perfluorohexadecylethyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, 2-chloroethyl (meth)acrylate, and 2-aminoethyl (meth)acrylate. The (meth)acrylic acid substituted alkyl esters may be used alone or in combination of two or more.

[0052] The (meth)acrylic acid ester polymer (B) may contain other acrylic monomer units such as (meth)acrylic acid, phenyl (meth)acrylate, toluyl (meth)acrylate, benzyl (meth)acrylate, and tetrahydrofurfuryl (meth)acrylate.

[0053] The method for synthesizing the (meth)acrylic acid ester polymer (B) is not particularly limited, and includes known methods, such as free radical polymerization, anionic polymerization, cationic polymerization, UV radical polymerization, living anionic polymerization, living cationic polymerization, and living radical polymerization.

[0054] Examples of free radical polymerization methods include a solution polymerization method in which a polymerization initiator, a chain transfer agent, a solvent, and the like are added to an acrylic monomer containing a (meth)acrylic acid ester containing a polyoxyethylene chain and, if necessary, a (meth)acrylic acid alkyl ester or a (meth)acrylic acid ester containing a hydrolyzable silyl group, and the acrylic monomer is polymerized at 50 to 150°C; and a continuous bulk polymerization method in which the acrylic monomer is polymerized at high temperature and high pressure, as described in JP-A-2001-207157.

[0055] The reaction is usually initiated using an oil-soluble radical initiator as the polymerization initiator, such as an azo-based polymerization initiator or an organic peroxide.

[0056] The azo polymerization initiator is not particularly limited, and examples thereof include 2,2'-azobis(2-methylbutyronitrile), dimethyl 2,2'-azobis(2-methylpropionate), 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile), 2,2'-azobis[N-(2-propenyl)-2-methylpropionamide], and 1,1'-azobis(cyclohexane-1-carbonitrile).

[0057] The organic peroxide is not particularly limited, and examples thereof include diacyl peroxides such as benzoyl peroxide, isobutyryl peroxide, isononanoyl peroxide, decanoyl peroxide, lauroyl peroxide, parachlorobenzoyl peroxide, and di(3,5,5-trimethylhexanoyl) peroxide; peroxydicarbonates such as diisopropyl peroxydicarbonate, di-sec-butyl peroxydicarbonate, di-2-ethylhexyl peroxydicarbonate, di-1-methylheptyl peroxydicarbonate, di-3-methoxybutyl peroxydicarbonate, and dicyclohexyl peroxydicarbonate; tert-butyl peroxybenzoate, tert-butyl peroxyacetate, tert-butyl peroxy- Examples of suitable radical polymerization initiators include peroxyesters such as 2-ethylhexanoate, tert-butylperoxyisobutyrate, tert-butylperoxypivalate, tert-butyldiperoxyadipate, and cumylperoxyneodecanoate; ketone peroxides such as methyl ethyl ketone peroxide and cyclohexanone peroxide; dialkyl peroxides such as di-tert-butyl peroxide, dicumyl peroxide, tert-butylcumyl peroxide, and 1,1-di(tert-hexylperoxy)-3,3,5-trimethylcyclohexane; hydroperoxides such as cumene hydroxyperoxide and tert-butyl hydroperoxide; and 1,1-di(tert-hexylperoxy)-3,3,5-trimethylcyclohexane. When using a peroxide as the radical polymerization initiator, it may be combined with a reducing agent to form a redox polymerization initiator. The polymerization initiators may be used alone or in combination.

[0058] Examples of chain transfer agents include mercapto group-containing compounds such as n-dodecyl mercaptan, tert-dodecyl mercaptan, and lauryl mercaptan. Furthermore, when it is desired to introduce a hydrolyzable silyl group into the molecular chain terminal of the (meth)acrylic acid ester polymer (B), examples of chain transfer agents include 3-mercaptopropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropylchloromethyldimethoxysilane, 3-mercaptopropylmethoxymethyldimethoxysilane, mercaptomethyltrimethoxysilane, and (mercaptomethyl)dimethoxymethylsilane. Chain transfer agents may be used alone or in combination of two or more. Because chain transfer agents can adversely affect weather resistance, the amount used is preferably 2% or less of the total amount of monomers, and it is particularly preferred that no chain transfer agent be used.

[0059] Examples of solvents include aromatic compounds such as toluene, xylene, styrene, ethylbenzene, paradichlorobenzene, di-2-ethylhexyl phthalate, and di-n-butyl phthalate; hydrocarbon compounds such as hexane, heptane, octane, cyclohexane, and methylcyclohexane; carboxylic acid ester compounds such as butyl acetate, n-propyl acetate, and isopropyl acetate; ketone compounds such as methyl isobutyl ketone and methyl ethyl ketone; dialkyl carbonate compounds such as dimethyl carbonate and diethyl carbonate; and alcohol compounds such as 1-propanol, 2-propanol, 1-butanol, 2-butanol, isobutanol, tert-butyl alcohol, and amyl alcohol. Among these, dimethyl carbonate, 1-propanol, 2-propanol, 1-butanol, 2-butanol, isobutanol, and tert-butyl alcohol are more preferred, and 2-propanol and isobutanol are particularly preferred.

[0060] The weight-average molecular weight of the (meth)acrylic acid ester polymer (B) is preferably 2,000 or more, more preferably 3,000 or more. On the other hand, the weight-average molecular weight of the (meth)acrylic acid ester polymer (B) is preferably 30,000 or less, more preferably 20,000 or less. When the weight-average molecular weight of the (meth)acrylic acid ester polymer (B) is 2,000 or more, the durability of the cured product of the curable composition can be improved. When the weight-average molecular weight of the (meth)acrylic acid ester polymer (B) is 30,000 or less, good workability of the curable composition can be maintained.

[0061] In the present invention, the weight average molecular weight of the (meth)acrylic acid ester polymer (B) refers to a value measured by GPC (gel permeation chromatography) in terms of polystyrene. In the measurement by GPC, for example, a Shodex KF800D manufactured by Tosoh Corporation is used as a GPC column, and chloroform or the like can be used as a solvent.

[0062] The content of the (meth)acrylic acid ester polymer (B) in the curable composition is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, and particularly preferably 15 parts by mass or more, per 100 parts by mass of the organic polymer (I) having a hydrolyzable silyl group. On the other hand, the content of the (meth)acrylic acid ester polymer (B) in the curable composition is preferably 200 parts by mass or less, more preferably 100 parts by mass or less, more preferably 75 parts by mass or less, more preferably 65 parts by mass or less, more preferably 60 parts by mass or less, more preferably 55 parts by mass or less, more preferably 50 parts by mass or less, more preferably 45 parts by mass or less, and even more preferably 40 parts by mass or less, per 100 parts by mass of the organic polymer (I) having a hydrolyzable silyl group. When the content of the (meth)acrylic acid ester polymer (B) is 5 parts by mass or more, the cured product of the curable composition maintains excellent rubber elasticity for a long period of time. When the content of the (meth)acrylic acid ester polymer (B) is 200 parts by mass or less, the coatability of the curable composition is improved.

[0063] (Fluoroalkyl Compound (C)) The curable composition of the present invention contains a fluoroalkyl compound (C). The use of the fluoroalkyl compound (C) can render the cured surface of the curable composition of the present invention superhydrophilic. This allows the water to spread thinly and easily flow off the cured surface without forming droplets when water, such as from rain, comes into contact with the cured surface of the curable composition. Therefore, even if contaminants such as dust adhere to the cured surface, the contaminants can be washed away with water such as rainwater (self-cleaning), thereby reducing the adhesion of contaminants. Furthermore, the fluoroalkyl compound (C) can also reduce the occurrence of rain streak stains when contaminants are washed away with water such as rainwater. Therefore, the curable composition of the present invention exhibits excellent contamination resistance after curing, thereby reducing the adhesion of contaminants and the occurrence of rain streak stains on the cured surface of the curable composition, thereby maintaining a beautiful appearance. Furthermore, by using the fluoroalkyl compound (C) in combination with the (meth)acrylic acid ester polymer (B) described above, the cured surface of the curable composition can maintain excellent contamination resistance for a long period of time. The fluoroalkyl compounds (C) may be used alone or in combination of two or more kinds.

[0064] The fluoroalkyl compound (C) is a compound having a fluoroalkyl group. The fluoroalkyl group is a group in which at least one hydrogen atom of an alkyl group is substituted with a fluorine atom. Among them, the fluoroalkyl group is preferably a group in which all hydrogen atoms of an alkyl group are substituted with fluorine atoms [perfluoroalkyl group (perfluoroalkyl group)]. It is preferable that the fluoroalkyl compound (C) does not have a hydrolyzable silyl group.

[0065] The number of carbon atoms in the fluoroalkyl group is preferably 1 or more, more preferably 2 or more, and more preferably 4 or more. The number of carbon atoms in the fluoroalkyl group is preferably 25 or less, more preferably 15 or less, and more preferably 10 or less. Examples of the fluoroalkyl group include CF3CH2-, CF3CF2CH2-, CF3(CF2)2CH2-, CF3(CF2)3CH2CH2-, CF3(CF2)4CH2CH2CH2-, CF3(CF2)4CH2-, CF3(CF2)5CH2CH2-, CF3(CF2)5CH2CH2CH2-, and (CF3)2CH-.

[0066] The fluoroalkyl compound (C) is preferably a surfactant having a fluoroalkyl group. Depending on the structure of the hydrophilic part, surfactants include anionic surfactants, cationic surfactants, nonionic surfactants, and amphoteric surfactants, with nonionic surfactants being preferred. A nonionic surfactant is a compound that does not ionize when dissolved in water.

[0067] The nonionic surfactant having a fluoroalkyl group preferably has a polyoxyalkylene chain. Preferred examples of the polyoxyalkylene chain include a polyoxyethylene chain and a polyoxypropylene chain. The number of repeating oxyalkylene units in the polyoxyalkylene chain is preferably 2 or more, more preferably 6 or more. The number of repeating oxyalkylene units in the polyoxyalkylene chain is preferably 30 or less, more preferably 20 or less.

[0068] The fluoroalkyl compound (C) may be a commercially available product, such as Surflon S-381, S-383, or KH-40, manufactured by AGC Seimi Chemical Co., Ltd.

[0069] As the fluoroalkyl compound (C), a polymer (CA) containing a (meth)acrylic acid ester unit represented by the following formula (2), a monomer unit having a hydrophilic group and a polymerizable unsaturated group, and a (meth)acrylic acid alkyl ester unit in which the alkyl group has 1 to 8 carbon atoms can be suitably used.

[0070] [ka]

[0071] However, in formula (2), R 6 is a perfluoroalkyl group having 1 to 6 carbon atoms, and R 7 is a hydrogen atom or a methyl group, and Z 1 is a single bond or a divalent organic group.

[0072] The polymer (CA) preferably used as the fluoroalkyl compound (C) contains a (meth)acrylic acid ester unit represented by the above formula (2). The polymer (CA) may contain one or more types of (meth)acrylic acid ester units represented by the formula (2).

[0073] In formula (2), R 6 is a perfluoroalkyl group having 1 to 6 carbon atoms. A perfluoroalkyl group refers to an atomic group in which all hydrogen atoms of an alkyl group have been substituted with fluorine atoms. The perfluoroalkyl group having 1 to 6 carbon atoms may be either linear or branched, but is preferably linear because it improves the stain resistance of the curable composition after curing.

[0074] In the perfluoroalkyl group, examples of the alkyl group before hydrogen is substituted with fluorine atoms include linear alkyl groups such as methyl, ethyl, propyl, n-butyl, n-pentyl, and n-hexyl groups, and branched alkyl groups such as isopropyl, isobutyl, sec-butyl, and tert-butyl groups.

[0075] Z 1 The divalent organic group is a group consisting of carbon atoms or R6 -O-, -NH-, -CO-, -S-, -SO2-, -CD 1 =CD 2 -(However, D 1 and D 2 are each independently a hydrogen atom or a methyl group).

[0076] Z 1 Examples of the alkylene group include a single bond, -CH2-, -CH2CH2-, -(CH2)3-, -CH(CH3)CH2CH2-, -CH2-CH=CH-, -CH2CH2-S-, -CH2CH2-S-CH2CH2-, and -CH2CH2-SO2-CH2CH2-. Alkylene groups such as -CH2CH2-, -(CH2)3-, and -CH(CH3)CH2CH2- are preferred because they provide excellent stability to the (meth)acrylic acid ester unit represented by formula (2).

[0077] Examples of the (meth)acrylic acid ester represented by formula (2) include: CF3CH2OC(O)CH=CH2, CF3CH2OC(O)C(CH3)=CH2, C2F5CH2OC(O)CH=CH2, C2F5CH2OC(O)C(CH3)=CH2, CF3CH2CH2OC(O)CH=CH2, CF3CH2CH2OC(O)C(CH3)=CH2, C2F5CH2CH2OC(O)CH=CH2, C2F5CH2CH2OC(O)C(CH3)=CH2, C3F7CH2CH2OC(O)CH=CH2, C3F7CH2CH2OC(O)C(CH3)=CH2, C4F9CH2CH2OC(O)CH=CH2, C4F9CH2CH2OC(O)C(CH3)=CH2, C5F 11 CH2CH2OC(O)CH=CH2, C5F 11CH2CH2OC(O)C(CH3)=CH2, C6F 13 CH2CH2OC(O)CH=CH2, C6F 13 CH2CH2OC(O)C(CH3)=CH2 Examples include:

[0078] The (meth)acrylic acid ester represented by formula (2) includes R 7 is a hydrogen atom or a methyl group, Z 1 is -CH2CH2-, R 6 (Meth)acrylic acid esters in which the alkyl group is a perfluoroalkyl group having 2 to 6 carbon atoms are preferred because they provide excellent stain resistance after the curable composition is cured.

[0079] The (meth)acrylic acid ester represented by formula (2) includes Z 1 is -CH2CH2-, R 6 is a perfluoroalkyl group having 6 carbon atoms, i.e., C6F 13 CH2CH2OC(O)CH=CH2 or C6F 13 CH2CH2OC(O)C(CH3)=CH2 is more preferred, and C6F 13 CH2CH2OC(O)C(CH3)=CH2 is more preferred.

[0080] The polymer (CA) preferably used as the fluoroalkyl compound (C) contains a monomer unit having a hydrophilic group and a polymerizable unsaturated group. The monomer unit having a hydrophilic group and a polymerizable unsaturated group may contain one or more types of monomer units.

[0081] The hydrophilic group is not particularly limited, and examples thereof include an alkylene oxide group (-R 10 O-;R 10 is an alkylene group), amino group, hydroxy group, acrylamide group (CH2=CHCONH-), carboxy group, phosphate group (-PO3 2- ), sulfone group (-SO2(OH)), and quaternary ammonium salts. 10The number of carbon atoms is preferably 1 to 5, and more preferably 1 to 3.

[0082] The polymerizable unsaturated group is not particularly limited, and examples thereof include CH2=CH-, CH2=CH-CH2-O-, and CH2=CR 9 -C(=O)O-, CH2=CR 9 -OC(=O)- (however, R 9 is a hydrogen atom, a chlorine atom, a fluorine atom, or a linear or branched alkyl group having 1 to 3 carbon atoms).

[0083] As the polymerizable unsaturated group, CH2=CH-, CH2=CH-CH2-O-, CH2=CH-C(=O)O-, CH2=C(CH3)-C(=O)O-, CH2=CH-OC(=O)-, and CH2=C(CH3)-OC(=O)- are more preferred because they provide excellent rubber elasticity in the curable composition after curing.

[0084] Examples of the monomer having a hydrophilic group and a polymerizable unsaturated group include the following monomers. CH2=CH-C(=O)-O-(CH2CH2O)2-H CH2=CH-C(=O)-O-(CH2CH2O)5-H CH2=CH-C(=O)-O-(CH2CH2O) 10 -H CH2=CH-C(=O)-O-(CH2CH2O) 24 -H CH2=C(CH3)-C(=O)-O-(CH2CH2O)2-H CH2=C(CH3)-C(=O)-O-(CH2CH2O)5-H CH2=C(CH3)-C(=O)-O-(CH2CH2O)8-H CH2=C(CH3)-C(=O)-O-(CH2CH2O) 10 -H CH2=C(CH3)-C(=O)-O-(CH2CH2O) 23 -H CH2=CH-C(=O)-O-(CH2CH2O)2-OCH3 CH2=CH-C(=O)-O-(CH2CH2O)4-OCH3 CH2=CH-C(=O)-O-(CH2CH2O)9-OCH3 CH2=CH-C(=O)-O-(CH2CH2O) 10 -OCH3 CH2=CH-C(=O)-O-(CH2CH2O) 13 -OCH3 CH2=C(CH3)-C(=O)-O-(CH2CH2O)2-OCH3 CH2=C(CH3)-C(=O)-O-(CH2CH2O)4-OCH3 CH2=C(CH3)-C(=O)-O-(CH2CH2O)9-OCH3 CH2=C(CH3)-C(=O)-O-(CH2CH2O) 13 -OCH3 CH2=C(CH3)-C(=O)-O-(CH2CH2O) 23 -OCH3 CH2=CH-C(=O)-OH CH2=C(CH3)-C(=O)-OH CH2=C(CH3)-C(=O)-CH2-CH2-NH3 CH2=CH-C(=O)-CH2-CH2-NH3 CH2=C(CH3)-C(=O)-N(CH3)2 CH2=CH-C(=O)-N(CH3)2 CH2=C(CH3)-C(=O)-N(CH2CH2OCH2CH2) CH2=CH-C(=O)-N(CH2CH2OCH2CH2) CH2=CH-C(=O)-NH-(CH2)3-N + (CH3)3·Cl - Examples include:

[0085] Since the stain resistance of the curable composition after curing is improved, the polymer (CA) is preferably -(R 11 It is preferable that the alkylene oxide chain has the formula (R)p-, where p represents an integer of 1 to 30. 11O) may be one or more types. 11 is an alkylene group, such as an ethylene group, a propylene group [-CH(CH3)-CH2-], a trimethylene group [-CH2-CH2-CH2-], a butylene group, an amylene group [-(CH2)5-], or a hexylene group.

[0086] The monomer having a hydrophilic group and a polymerizable unsaturated group preferably has a structural formula represented by the following formula (3). Q 1 -Z 2 -(CH2CH2O)qR 8 (3) However, in equation (3), Q 1 is a monovalent substituent containing a polymerizable unsaturated group, and Z 2 is a single bond or a linear alkylene group having 1 to 10 carbon atoms, and R 8 represents a hydrogen atom or a methyl group, and q represents an integer of 1 to 30.

[0087] Q 1 Examples include CH2=CH-, CH2=CH-CH2-O-, and CH2=CR 9 -C(=O)O-, CH2=CR 9 -OC(=O)- is preferred (however, R 9 is a hydrogen atom, a chlorine atom, a fluorine atom, or a linear or branched alkyl group having 1 to 3 carbon atoms. q is preferably an integer of 1 to 30, and more preferably an integer of 4 to 26.

[0088] The monomer represented by formula (3) is preferably Q because it improves the stain resistance of the curable composition after curing. 1 CH2=CR 9 -C(=O)O-, R 9 is a hydrogen atom or a methyl group, Z 2 is a single bond, R 8 is a methyl group and q is 1 to 30, 1 CH2=CH-C(=O)O-, R 8 is a methyl group, Z 2 Monomers in which is a single bond and q is 4 to 26 are more preferred.

[0089] The polymer (CA) preferably used as the fluoroalkyl compound (C) contains (meth)acrylic acid alkyl ester units in which the alkyl group has 1 to 8 carbon atoms. One or more types of (meth)acrylic acid alkyl ester units may be contained in the polymer (CA). The hydrogen atoms of the alkyl group of the (meth)acrylic acid alkyl ester are not substituted with other atoms or atomic groups.

[0090] Examples of (meth)acrylic acid alkyl esters having an alkyl group with 1 to 8 carbon atoms include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, sec-butyl (meth)acrylate, n-hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, and isooctyl (meth)acrylate, with butyl acrylate being preferred and n-butyl acrylate being more preferred.

[0091] In the polymer (CA), the content of the (meth)acrylic acid ester units represented by formula (2) is preferably 5% by mass or more, more preferably 10% by mass or more, more preferably 15% by mass or more, more preferably 20% by mass or more, more preferably 25% by mass or more, and more preferably 30% by mass or more. In the polymer (CA), the content of the (meth)acrylic acid ester units represented by the following formula (2) is preferably 50% by mass or less, more preferably 45% by mass or less, preferably 40% by mass or less, and more preferably 35% by mass or less. When the content of the (meth)acrylic acid ester units represented by formula (2) is 5% by mass or more, the stain resistance of the curable composition after curing is improved. When the content of the (meth)acrylic acid ester units represented by formula (2) is 50% by mass or less, the stain resistance of the curable composition after curing is improved.

[0092] In the polymer (CA), the content of the monomer unit having a hydrophilic group and a polymerizable unsaturated group is preferably 5% by mass or more, more preferably 10% by mass or more, more preferably 15% by mass or more, more preferably 20% by mass or more, more preferably 25% by mass or more, and more preferably 30% by mass or more. In the polymer (CA), the content of the monomer unit having a hydrophilic group and a polymerizable unsaturated group is preferably 50% by mass or less, more preferably 45% by mass or less, preferably 40% by mass or less, and more preferably 35% by mass or less. When the content of the monomer unit having a hydrophilic group and a polymerizable unsaturated group is 5% by mass or more, the stain resistance of the curable composition after curing is improved. When the content of the monomer unit having a hydrophilic group and a polymerizable unsaturated group is 50% by mass or less, the stain resistance of the curable composition after curing is improved.

[0093] In the polymer (CA), the content of (meth)acrylic acid alkyl ester units having an alkyl group with 1 to 8 carbon atoms is preferably 5% by mass or more, more preferably 10% by mass or more, more preferably 15% by mass or more, more preferably 20% by mass or more, more preferably 25% by mass or more, and more preferably 30% by mass or more. In the polymer (CA), the content of (meth)acrylic acid alkyl ester units having an alkyl group with 1 to 8 carbon atoms is preferably 50% by mass or less, more preferably 45% by mass or less, preferably 40% by mass or less, and more preferably 35% by mass or less. When the content of (meth)acrylic acid alkyl ester units having an alkyl group with 1 to 8 carbon atoms is 5 mass or more, the stain resistance of the curable composition after curing is improved. When the content of (meth)acrylic acid alkyl ester units having an alkyl group with 1 to 8 carbon atoms is 40 mass or less, the stain resistance of the curable composition after curing is improved.

[0094] In the polymer (CA), the total content of the (meth)acrylic acid ester units represented by the following formula (2), the monomer units having a hydrophilic group and a polymerizable unsaturated group, and the (meth)acrylic acid alkyl ester units in which the alkyl group has 1 to 8 carbon atoms is preferably 80% by mass or more, more preferably 85% by mass or more, more preferably 90% by mass or more, more preferably 95% by mass or more, and more preferably 100% by mass.

[0095] The content of the fluoroalkyl compound (C) in the curable composition is preferably 0.2 parts by mass or more, more preferably 1 part by mass or more, more preferably 2 parts by mass or more, and particularly preferably 2.5 parts by mass or more, per 100 parts by mass of the organic polymer (I) having a hydrolyzable silyl group. On the other hand, the content of the fluoroalkyl compound (C) in the curable composition is preferably 30 parts by mass or less, more preferably 10 parts by mass or less, and particularly preferably 5 parts by mass or less, per 100 parts by mass of the organic polymer (I) having a hydrolyzable silyl group. When the content of the fluoroalkyl compound (C) is 0.2 parts by mass or more, a good self-cleaning effect can be imparted to the surface of the cured product of the curable composition. When the content of the fluoroalkyl compound (C) is 10 parts by mass or less, the rubber elasticity of the cured product of the curable composition is improved.

[0096] The mass ratio of the organic polymer (I) having a hydrolyzable silyl group to the fluoroalkyl compound (C) [mass of the organic polymer (I) having a hydrolyzable silyl group / mass of the fluoroalkyl compound (C)] is preferably 15 or more, more preferably 20 or more, and particularly preferably 25 or more. On the other hand, the mass ratio of the organic polymer (I) having a hydrolyzable silyl group to the fluoroalkyl compound (C) [mass of the organic polymer (I) having a hydrolyzable silyl group / mass of the fluoroalkyl compound (C)] is preferably 110 or less, more preferably 50 or less, more preferably 45 or less, and particularly preferably 40 or less. When the mass ratio is 15 or more, contaminants adhering to the surface of the cured product of the curable composition can be easily removed with water. When the mass ratio is 110 or less, deterioration of the cured product of the curable composition due to water can be reduced.

[0097] The mass ratio of the (meth)acrylic acid ester polymer (B) to the fluoroalkyl compound (C) [mass of the (meth)acrylic acid ester polymer (B) / mass of the fluoroalkyl compound (C)] is preferably 1 or more, more preferably 3 or more, and particularly preferably 5 or more. On the other hand, the mass ratio of the (meth)acrylic acid ester polymer (B) to the fluoroalkyl compound (C) [mass of the (meth)acrylic acid ester polymer (B) / mass of the fluoroalkyl compound (C)] is preferably 20 or less, more preferably 15 or less, and particularly preferably 10 or less. When the mass ratio is 1 or more, excellent durability can be imparted to the cured product of the curable composition. When the mass ratio is 20 or less, excellent self-cleaning properties with water can be imparted to the surface of the cured product of the curable composition.

[0098] (Silanol condensation catalyst (D)) The curable composition of the present invention contains a silanol condensation catalyst (D), which is a catalyst for promoting a dehydration condensation reaction between silanol groups formed by hydrolysis of hydrolyzable silyl groups contained in the organic polymer (I) or the like.

[0099] The silanol condensation catalyst (D) is not particularly limited, and examples thereof include dioctyltin monodecanoate, 1,1,3,3-tetrabutyl-1,3-dilauryloxycarbonyl-distannoxane, dibutyltin dilaurate, dibutyltin oxide, dibutyltin diacetate, dibutyltin phthalate, bis(dibutyltin laurate) oxide, dibutyltin bis(acetylacetonate), dibutyltin bis(monoester maleate), tin octoate, dibutyltin octoate, dioctyltin oxide, dibutyltin bis(triethoxysilicate), bis(dibutyltin bistriethoxysilicate) oxide, and dibutyltin oxybisethoxysilicate; and organic titanium compounds such as tetra-n-butoxy titanate and tetraisopropoxy titanate. Among these, organic tin compounds are preferred, and dioctyltin oxide is more preferred. These silanol condensation catalysts may be used alone or in combination of two or more.

[0100] The content of the silanol condensation catalyst (D) in the curable composition is preferably 0.1 parts by mass or more, more preferably 0.2 parts by mass or more, and more preferably 0.3 parts by mass or more, per 100 parts by mass of the organic polymer (I) having a hydrolyzable silyl group. The content of the silanol condensation catalyst (D) in the curable composition is preferably 10 parts by mass or less, more preferably 8 parts by mass or less, more preferably 6 parts by mass or less, and more preferably 5 parts by mass or less, per 100 parts by mass of the organic polymer (I) having a hydrolyzable silyl group. When the content of the silanol condensation catalyst (D) in the curable composition is 0.1 parts by mass or more, the curing rate of the curable composition can be increased, and the time required for curing the curable composition can be shortened. When the content of the silanol condensation catalyst (D) in the curable composition is 10 parts by mass or less, the curable composition has an appropriate curing rate, and the storage stability and handleability of the curable composition can be improved.

[0101] (aminosilane compound) The curable composition of the present invention preferably contains an aminosilane compound. The aminosilane compounds may be used alone or in combination of two or more. Preferred examples of the aminosilane compound include aminoalkoxysilanes. The aminoalkoxysilane refers to a compound having at least one amino group-containing functional group and at least two alkoxy groups directly bonded to a silicon atom in one molecule. The amino group-containing functional group is preferably directly bonded to a silicon atom. The aminoalkoxysilane is preferably a compound having one amino group-containing functional group and three alkoxy groups directly bonded to a silicon atom in one molecule. It is preferable that the aminosilane compound does not have a fluoroalkyl group.

[0102] The amino group-containing functional group is preferably an aminopropyl functional group, since it improves the adhesiveness of the curable composition. Examples of the aminopropyl functional group include -(CH2)3-NH2 and -(CH2)3-NHR 5At least one aminopropyl functional group selected from the group consisting of -(CH)-NH(CH)-NH (3-[N-(2-aminoethyl)amino]propyl group), and -(CH)-NH(CH)-NH(CH)-NH (3-[[2-(2-aminoethylamino)ethyl]amino]propyl group) is preferred. As the aminopropyl functional group, -(CH)-NH and -(CH)-NH(CH)-NH are more preferred.

[0103] -(CH2)3-NHR 5 In R 5 is an alkyl group having 1 to 18 carbon atoms, a monovalent saturated alicyclic hydrocarbon group having 3 to 18 carbon atoms, or an aryl group having 6 to 12 carbon atoms.

[0104] R 5 In the formula (I), examples of the alkyl group having 1 to 18 carbon atoms include linear alkyl groups and branched alkyl groups. Examples of linear alkyl groups include methyl, ethyl, propyl, n-butyl, n-pentyl, n-hexyl, n-octyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl, n-tridecyl, n-tetradecyl, n-pentadecyl, n-hexadecyl, n-heptadecyl, and n-octadecyl groups. Preferred linear alkyl groups are methyl, ethyl, and n-butyl. Examples of branched alkyl groups include isopropyl, isobutyl, sec-butyl, and tert-butyl groups.

[0105] R 5 In the above formula, examples of the monovalent saturated alicyclic hydrocarbon group having 3 to 18 carbon atoms include a cyclopentyl group, a cycloheptyl group, a cyclohexyl group, a 4-methylcyclohexyl group, and a cyclooctyl group, with a cyclohexyl group being preferred.

[0106] R 5 In the above, examples of the aryl group having 6 to 12 carbon atoms include a phenyl group.

[0107] Specific examples of aminoalkoxysilanes include 3-aminopropyltrimethoxysilane, 3-aminopropylmethyldimethoxysilane, 3-aminopropyltriethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropyltriethoxysilane, N,N'-bis-[3-(trimethoxysilyl)propyl]ethylenediamine, N,N'-bis-[3-(triethoxysilyl)propyl]ethylenediamine, N,N'-bis-[3-(methyldimethoxysilyl)propyl]ethylenediamine, N,N'-bis-[3-(trimethoxysilyl)propyl]hexamethylenediamine, and N,N'-bis-[3-(triethoxysilyl)propyl]hexamethylenediamine, with N-2-(aminoethyl)-3-aminopropyltrimethoxysilane being preferred. The aminoalkoxysilanes may be used alone or in combination of two or more.

[0108] The aminosilane compound may be the aminoalkoxysilane described above or a hydrolysis condensate of the aminoalkoxysilane. Examples of the aminosilane compound include an alkoxysilane oligomer, which is a hydrolysis condensate of the aminoalkoxysilane, and an alkoxysilane oligomer, which is a hydrolysis condensate of the aminoalkoxysilane and the alkylalkoxysilane. That is, examples of the aminosilane compound include an alkoxysilane oligomer obtained by hydrolyzing an aminoalkoxysilane and then condensing it, and an alkoxysilane oligomer obtained by hydrolyzing an aminoalkoxysilane and an alkylalkoxysilane and then condensing it.

[0109] Alkylalkoxysilane refers to a compound in which at least one alkyl group and at least two alkoxy groups are directly bonded to a silicon atom. Examples of alkylalkoxysilanes include monoalkyltrialkoxysilanes in which one alkyl group and three alkoxy groups are directly bonded to a silicon atom, and dialkyldialkoxysilanes in which two alkyl groups and two alkoxy groups are directly bonded to a silicon atom. Specific examples of monoalkyltrialkoxysilanes include methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, and hexyltrimethoxysilane. Specific examples of dialkyldialkoxysilanes include dimethyldimethoxysilane, dimethyldiethoxysilane, diethyldimethoxysilane, and diethyldiethoxysilane. Among these, monoalkyltrialkoxysilanes are preferred, and ethyltriethoxysilane is more preferred. The alkylalkoxysilanes may be used alone or in combination.

[0110] The content of the aminosilane compound in the curable composition is preferably 0.1 parts by mass or more, more preferably 0.5 parts by mass or more, and particularly preferably 1 part by mass or more, per 100 parts by mass of the organic polymer (I) having a hydrolyzable silyl group. On the other hand, the content of the aminosilane compound in the curable composition is preferably 10 parts by mass or less, more preferably 5 parts by mass or less, and particularly preferably 3 parts by mass or less, per 100 parts by mass of the organic polymer (I) having a hydrolyzable silyl group. When the content of the aminosilane compound is 0.1 parts by mass or more, the adhesiveness of the curable composition is improved. When the content of the aminosilane compound is 10 parts by mass or less, the curability of the curable composition is improved.

[0111] (filler) The curable composition preferably further contains a filler, which makes it possible to provide a curable composition that can give a cured product having excellent mechanical strength.

[0112] Examples of fillers include calcium carbonate, magnesium carbonate, calcium oxide, hydrous silicic acid, anhydrous silicic acid, finely powdered silica, calcium silicate, titanium dioxide, clay, talc, carbon black, and glass balloons. Calcium carbonate is preferred, and colloidal calcium carbonate and heavy calcium carbonate are also preferred. These fillers may be used alone or in combination of two or more.

[0113] The average particle size of calcium carbonate is preferably 0.01 to 5 μm, more preferably 0.05 to 2.5 μm. Calcium carbonate having such an average particle size can provide a cured product having excellent mechanical strength and elongation, and can also provide a curable composition having excellent adhesiveness.

[0114] Furthermore, the calcium carbonate is preferably surface-treated with a fatty acid, a fatty acid ester, etc. Calcium carbonate surface-treated with a fatty acid, a fatty acid ester, etc. can impart thixotropy to the curable composition and can also inhibit aggregation of calcium carbonate.

[0115] The content of the filler in the curable composition is preferably 1 part by mass or more, more preferably 10 parts by mass or more, and particularly preferably 50 parts by mass or more, per 100 parts by mass of the organic polymer (I) having a hydrolyzable silyl group. On the other hand, the content of the filler in the curable composition is preferably 700 parts by mass or less, more preferably 250 parts by mass or less, and particularly preferably 200 parts by mass or less, per 100 parts by mass of the organic polymer (I) having a hydrolyzable silyl group. When the content of the filler in the curable composition is 1 part by mass or more, the effect of adding the filler can be sufficiently obtained. Furthermore, when the content of the filler in the curable composition is 700 parts by mass or less, the cured product obtained by curing the curable composition has excellent rubber elasticity.

[0116] (plasticizer) The curable composition may contain a plasticizer. In the case of a composition other than a polymer or oligomer, a compound having a molecular weight of 300 to 10,000 is used as the plasticizer. In the case of a polymer or oligomer, a polymer having a weight-average molecular weight of 400 to 11,000 is preferably used as the plasticizer. Specific examples include phthalate esters such as dioctyl phthalate, dibutyl phthalate, and butyl benzyl phthalate, polyalkylene oxides such as polypropylene glycol, and acrylic polymers, with acrylic polymers being preferred. The acrylic polymer preferably does not contain a hydrolyzable silyl group. Furthermore, the acrylic polymer preferably does not contain a (meth)acrylic acid ester unit containing a polyoxyethylene chain. Furthermore, the acrylic polymer preferably does not contain a fluoroalkyl group. To prevent a decrease in rubber elasticity over time, the acrylic polymer may contain a hydrolyzable silyl group, and preferably contains an average of 0.1 to 0.5 hydrolyzable silyl groups per molecule. The weight-average molecular weight of the acrylic polymer is preferably 500 or more, more preferably 1000 or more. The weight-average molecular weight of the acrylic polymer is preferably 10000 or less, more preferably 5000 or less. When the weight-average molecular weight of the acrylic polymer is 500 or more, bleeding out of the acrylic polymer can be suppressed. When the weight-average molecular weight of the acrylic polymer is 10000 or less, the curable composition is sufficiently plasticized, and the cured product of the curable composition has excellent rubber elasticity.

[0117] In the present invention, when the plasticizer is a polymer, the weight-average molecular weight of the plasticizer is a value measured in terms of polystyrene by gel permeation chromatography (GPC). In the measurement by GPC, for example, a Shodex KF800D manufactured by Tosoh Corporation is used as the GPC column, and chloroform or the like can be used as the solvent.

[0118] The content of the plasticizer in the curable composition is preferably 1 part by mass or more, more preferably 10 parts by mass or more, relative to 100 parts by mass of the organic polymer (I) having a hydrolyzable silyl group. The content of the plasticizer in the curable composition is preferably 100 parts by mass or less, more preferably 70 parts by mass or less, relative to 100 parts by mass of the organic polymer (I) having a hydrolyzable silyl group.

[0119] [Dehydrating agent] The curable composition preferably further contains a dehydrating agent, which can prevent the curable composition from being cured by moisture contained in the air or the like during storage.

[0120] Examples of dehydrating agents include silane compounds such as vinyltrimethoxysilane, dimethyldimethoxysilane, tetraethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, tetramethoxysilane, phenyltrimethoxysilane, and diphenyldimethoxysilane; and ester compounds such as methyl orthoformate, ethyl orthoformate, methyl orthoacetate, and ethyl orthoacetate. These dehydrating agents may be used alone or in combination. Among them, vinyltrimethoxysilane is preferred.

[0121] The content of the dehydrating agent in the curable composition is preferably 0.5 parts by mass or more, more preferably 1 part by mass or more, per 100 parts by mass of the organic polymer (I) having a hydrolyzable silyl group. On the other hand, the content of the dehydrating agent in the curable composition is preferably 20 parts by mass or less, more preferably 15 parts by mass or less, per 100 parts by mass of the organic polymer (I) having a hydrolyzable silyl group. When the content of the dehydrating agent in the curable composition is 0.5 parts by mass or more, the effects obtained by the dehydrating agent are sufficiently obtained. Furthermore, when the content of the dehydrating agent in the curable composition is 20 parts by mass or less, the curable composition has excellent curability.

[0122] (light stabilizer) The curable composition may further contain a light stabilizer. Examples of the light stabilizer include hindered amine light stabilizers. The hindered amine light stabilizer can provide a curable composition that can maintain excellent rubber elasticity for a longer period of time after curing.

[0123] Examples of hindered amine light stabilizers include a mixture of bis(1,2,2,6,6-pentamethyl-4-piperidyl) sebacate and methyl 1,2,2,6,6-pentamethyl-4-piperidyl sebacate, bis(2,2,6,6-tetramethyl-4-piperidyl) sebacate, dibutylamine·1,3,5-triazine·N,N'-bis(2,2,6,6-tetramethyl-4-piperidyl-1,6-hexamethylenediamine) and N-(2,2,6,6-tetramethyl-4-piperidyl)butyl Examples of the hindered amine light stabilizer include a polycondensate of dimethyl succinate and 4-hydroxy-2,2,6,6-tetramethyl-1-piperidineethanol, a polycondensate of dimethyl succinate and 4-hydroxy-2,2,6,6-tetramethyl-1-piperidineethanol, and the like.

[0124] The content of the hindered amine light stabilizer in the curable composition is preferably 0.01 parts by mass or more, more preferably 0.1 parts by mass or more, relative to 100 parts by mass of the organic polymer (I) having a hydrolyzable silyl group, while the content of the hindered amine light stabilizer in the curable composition is preferably 20 parts by mass or less, more preferably 10 parts by mass or less, relative to 100 parts by mass of the organic polymer (I) having a hydrolyzable silyl group.

[0125] (Other additives) The curable composition may contain other additives such as a thixotropic agent, an antioxidant, an ultraviolet absorber, a pigment, a dye, an anti-settling agent, and a solvent. Among these, the thixotropic agent, the ultraviolet absorber, and the antioxidant are preferred.

[0126] The thixotropy-imparting agent may be any agent capable of imparting thixotropy to the curable composition, and preferred examples of the thixotropy-imparting agent include hydrogenated castor oil, fatty acid bisamide, and fumed silica.

[0127] The content of the thixotropy-imparting agent in the curable composition is preferably 0.1 parts by mass or more, more preferably 1 part by mass or more, per 100 parts by mass of the organic polymer (I) having a hydrolyzable silyl group. The content of the thixotropy-imparting agent in the curable composition is preferably 200 parts by mass or less, more preferably 150 parts by mass or less, per 100 parts by mass of the organic polymer (I) having a hydrolyzable silyl group. When the content of the thixotropy-imparting agent in the curable composition is 0.1 parts by mass or more, thixotropy can be effectively imparted to the curable composition. Furthermore, when the content of the thixotropy-imparting agent in the curable composition is 200 parts by mass or less, the curable composition has an appropriate viscosity, improving the handleability of the curable composition.

[0128] Examples of the ultraviolet absorber include benzotriazole-based ultraviolet absorbers and benzophenone-based ultraviolet absorbers, with benzotriazole-based ultraviolet absorbers being preferred. The content of the ultraviolet absorber in the curable composition is preferably 0.1 parts by mass or more, more preferably 0.5 parts by mass or more, relative to 100 parts by mass of the organic polymer (I) having a hydrolyzable silyl group. The content of the ultraviolet absorber in the curable composition is preferably 20 parts by mass or less, more preferably 10 parts by mass or less, relative to 100 parts by mass of the organic polymer (I) having a hydrolyzable silyl group.

[0129] Examples of antioxidants include hindered phenol antioxidants, monophenol antioxidants, bisphenol antioxidants, and polyphenol antioxidants. The content of the antioxidant in the curable composition is preferably 0.1 parts by mass or more, more preferably 0.3 parts by mass or more, per 100 parts by mass of the organic polymer (I) having a hydrolyzable silyl group. The content of the antioxidant in the curable composition is preferably 20 parts by mass or less, more preferably 10 parts by mass or less, per 100 parts by mass of the organic polymer (I) having a hydrolyzable silyl group.

[0130] The curable composition of the present invention can form a cured product that can maintain excellent rubber elasticity for a long period of time, and therefore can be used in various applications such as sealants, coating materials, adhesives, paints, etc. Among these, it is preferably used as a sealant, and more preferably used as a sealant for joint structures.

[0131] Furthermore, the cured product of the curable composition of the present invention has excellent contamination resistance, which reduces adhesion of contaminants and the occurrence of rain streaks, and can maintain a beautiful appearance for a long period of time, especially when used outdoors.

[0132] A method of applying a curable composition to a joint portion to obtain a joint structure involves filling the joint portion with the curable composition and then curing the composition to harden it. The resulting joint structure comprises wall members that constitute the walls of an architectural structure and a cured product of the curable composition that has been filled into the joint portion formed between adjacent wall members. Examples of the wall portion of an architectural structure include exterior walls, interior walls, and ceiling portions, with exterior walls being preferred. Examples of wall members include exterior wall members, interior wall members, and ceiling members, with exterior wall members being preferred.

[0133] The joints are not particularly limited, and examples thereof include joints in the exterior walls, interior walls, and ceilings of architectural structures. The curable composition of the present invention can exhibit excellent contamination resistance after curing. Furthermore, the curable composition of the present invention can maintain excellent rubber elasticity for a long period of time after curing, and therefore exhibits excellent followability to changes in the width of the joints due to expansion or contraction of components caused by temperature changes such as air temperature or sunlight, or due to the effects of vibration or wind pressure, and can prevent damage to components and water leakage into architectural structures. Therefore, the curable composition of the present invention can be used in joints in the exterior walls of architectural structures, which are also called "working joints." It is suitable for use in sealing joints that are prone to adhesion of pollutants and rain stains.

[0134] Examples of joints in the exterior walls of building structures include joints that occur at the joints between exterior wall components such as mortar boards, concrete boards, ceramic siding boards, metal siding boards, ALC boards, and metal plates. [Effects of the Invention]

[0135] The curable composition of the present invention has the above-mentioned constitution, and therefore after curing, it exhibits excellent stain resistance and can maintain excellent rubber elasticity for a long period of time. DETAILED DESCRIPTION OF THE INVENTION

[0136] The present invention will be described in more detail below using examples, but the present invention is not limited to these examples. [Example]

[0137] [Synthesis of (meth)acrylic acid ester polymers (B1) to (B3)] 30 parts by mass of isobutanol was added to a flask, heated to 105°C, and the mixture was purged with nitrogen. Then, under a nitrogen atmosphere, a predetermined amount of methoxypolyethylene glycol methacrylate (formula (1) (wherein R 2 is a methyl group, m is 9, and R 3A solution containing a (meth)acrylic acid ester represented by the formula (I) (wherein R is a methyl group), molecular weight: 468, manufactured by Shin-Nakamura Chemical Co., Ltd., trade name "NK Ester M-90G"), butyl acrylate, 3-(trimethoxysilyl)propyl methacrylate, a polymerization initiator (2,2'-azobis(2-methylbutyronitrile), manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., trade name "V-59"), and isobutanol was added dropwise over 5 hours, followed by polymerization for 1 hour. The isobutanol was removed from the resulting isobutanol solution of the (meth)acrylic acid ester polymer under heating and reduced pressure, yielding (meth)acrylic acid ester polymers (B1) to (B3) having the weight-average molecular weights (Mw) shown in Table 1.

[0138] [Synthesis of fluoroalkyl compound (C3) [polymer (CA)]] 200 parts by mass of butyl acrylate, C6FMA (C6F 13 200 parts by mass of CH2CH2OC(O)C(CH3)=CH2) and methoxypolyethylene glycol acrylate (manufactured by NOF Corporation, trade name "AME400", CH2=CH-C(=O)-O-(CH2CH2O) 10 -OCH3, in formula (3), Q 1 CH2=CH-C(=O)O-, R 8 is a methyl group, Z 2 To a monomer mixture containing 200 parts by mass of (wherein is a single bond and q is 10), 7.5 parts by mass of n-dodecyl mercaptan and 10 parts by mass of 2,2'-azobis-2-methylbutyronitrile were added.

[0139] The monomer mixture was added dropwise to 600 parts by mass of ethyl acetate heated to 80°C over 2 hours, and then the monomer mixture was polymerized for 2 hours to obtain a polymer (CA) to be used as the fluoroalkyl compound (C).

[0140] The following compounds were used in the examples and comparative examples. [Polyalkylene oxide (A)] Polyalkylene oxide (A1) containing methyldimethoxysilyl groups and having a main chain structure of polypropylene oxide (AGC Inc., product name "Excestar S4530", number average molecular weight (Mn): 25,000, molecular weight distribution (Mw / Mn): 1.16) Polyalkylene oxide (A2) containing methyldimethoxysilyl groups and having a main chain structure of polypropylene oxide (AGC Corporation, product name "Excestar S6735D," number average molecular weight (Mn): 30,000, molecular weight distribution (Mw / Mn): 1.15) Polyalkylene oxide (A3) containing no hydrolyzable silyl or fluoroalkyl groups (AGC Corporation, product name "Exestar S2420", number average molecular weight (Mn): 17,000, molecular weight distribution (Mw / Mn): 1.4) The polyalkylene oxide (A1) and the polyalkylene oxide (A2) did not contain a fluoroalkyl group and did not contain a (meth)acrylic acid ester unit containing a polyoxyethylene chain.

[0141] [Fluoroalkyl Compound (C)] Fluoroalkyl compound (C1) (a nonionic surfactant (oligomer type) having a fluoroalkyl group and not containing a hydrolyzable silyl group, manufactured by AGC Seimi Chemical Co., Ltd., product name "Surflon S-656") Fluoroalkyl compound (C2) (a nonionic surfactant having a fluoroalkyl group and not containing a hydrolyzable silyl group, manufactured by AGC Seimi Chemical Co., Ltd., product name "Surflon S-431") Fluoroalkyl compound (C3) [the above polymer (CA)]

[0142] [Silanol condensation catalyst (D)] Silanol condensation catalyst (D) (dioctyltin oxide)

[0143] [Aminosilane Compound] Aminosilane compound (N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, product name "KBM-603" manufactured by Shin-Etsu Chemical Co., Ltd.)

[0144] [Filler] Colloidal calcium carbonate (Konoshima Chemical Co., Ltd., product name "PLS-505", average particle size: 0.1 μm) Heavy calcium carbonate (Shiraishi Calcium Co., Ltd., product name "Whiten SB", average particle size: 2.0 μm)

[0145] [Plasticizer] Plasticizer (acrylic polymer not containing hydrolyzable silyl groups or fluoroalkyl groups, weight-average molecular weight: 2000, manufactured by Toagosei Co., Ltd., product name "Arfon UP1110") [Dehydrating agent] Dehydrating agent (vinyltrimethoxysilane, product name "KBM-1003" manufactured by Shin-Etsu Chemical Co., Ltd.) [Antioxidants] Hindered phenol antioxidant (BASF Japan, product name "Irganox 1010") [Ultraviolet absorber] Benzotriazole UV absorber (product name "Tinuvin 326" manufactured by BASF Japan Ltd.)

[0146] (Examples 1 to 9 and Comparative Examples 1 to 4) The polyalkylene oxides (A1) to (A3), (meth)acrylic acid ester polymers (B1) to (B3), fluoroalkyl compounds (C1) to (C3), silanol condensation catalyst (D), aminosilane compound, colloidal calcium carbonate, heavy calcium carbonate, plasticizer, dehydrating agent, hindered phenol-based antioxidant, and benzotriazole-based ultraviolet absorber were mixed in the amounts shown in Table 2 in a sealed mixer under reduced pressure until uniform, thereby obtaining a curable composition.

[0147] [Elongation at maximum load (initial)] An H-shaped specimen was prepared using the curable composition in accordance with JIS A1439 5.17 (2010). Specifically, two anodized aluminum plates (50 mm long x 50 mm wide, 5 mm thick) were used, and a spacer was sandwiched between them to form a rectangular parallelepiped space (12 mm long x 50 mm wide x 12 mm high) in the center between the plates. The curable composition was then filled into this space without allowing air to enter. After filling with the curable composition, the curable composition was left in an atmosphere at 23°C and 50% relative humidity for 14 days. Thereafter, the curable composition was left in an atmosphere at 30°C for another 14 days. The curable composition was cured and cured to prepare an H-shaped specimen consisting of two anodized aluminum plates bonded together by the cured product of the curable composition.

[0148] The H-shaped specimens thus prepared were subjected to a tensile test at a tension rate of 50 mm / min in accordance with JIS A1439 5.20.4 (2010) in an atmosphere of 23°C and 50% relative humidity, and the elongation at maximum load [%] was measured. After the tensile test, the fracture morphology of the cured product of the curable composition was visually inspected and evaluated according to the following criteria. The results are shown in the "Initial" column in Table 2.

[0149] [Maximum load elongation (1 month in water at 23°C)] H-shaped specimens were prepared in the same manner as above. The prepared H-shaped specimens were left completely submerged in water at 23°C for one month, then removed from the water and left in an atmosphere at 23°C and 50% relative humidity for an additional 24 hours. A tensile test was then performed at 23°C and 50% relative humidity at a tension rate of 50 mm / min in accordance with JIS A1439 5.20.4 (2010), and the elongation at maximum load [%] was measured. Furthermore, after the tensile test, the fracture morphology of the cured curable composition was visually confirmed and evaluated according to the following criteria. The results are shown in the "23°C water 1 month" column in Table 2.

[0150] [Maximum elongation (1 month in water at 50°C)] H-shaped specimens were prepared in the same manner as above. The H-shaped specimens were left completely submerged in 50°C water for one month, then removed from the water and left in an atmosphere of 23°C and 50% relative humidity for another 24 hours. A tensile test was then performed in accordance with JIS A1439 5.20.4 (2010) at a tension rate of 50 mm / min in an atmosphere of 23°C and 50% relative humidity, and the elongation at maximum load [%] was measured. Furthermore, after the tensile test, the fracture morphology of the cured curable composition was visually confirmed and evaluated according to the following criteria. The results are shown in the "50°C water for 1 month" column in Table 2. Regarding the H-shaped specimens produced using the curable compositions of Comparative Examples 2 to 4, when the H-shaped specimens were left completely submerged in water at 50°C for one month and then removed from the water, peeling occurred between the cured product of the curable composition and the anodized aluminum plate, making it impossible to measure the elongation at maximum load.

[0151] The evaluation criteria for the fracture morphology of the cured curable composition were as follows: after the tensile test, if the cured curable composition underwent cohesive failure, it was rated as "CF", and if the cured curable composition underwent interfacial failure, it was rated as "AF".

[0152] Cohesive failure of a cured product refers to a state in which the cured product itself breaks in a tensile test. Interfacial failure of a cured product refers to a state in which the cured product peels off at the interface between the anodized aluminum plate and the cured product in a tensile test. The higher the adhesive strength of a cured product of a curable composition, the more cohesive failure occurs, and the lower the adhesive strength of a cured product of a curable composition, the more interfacial failure occurs.

[0153] [Stain resistance (after long-term exposure test)] A 2-mm thick coating of the curable composition was applied to a release-treated polyethylene terephthalate (PET) substrate at 23°C and cured for four weeks. A sheet-like specimen consisting of the cured product of the curable composition was then prepared on the PET substrate. The PET substrate was then peeled from the sheet-like specimen, and the sheet-like specimen alone was attached to an aluminum plate to obtain a laminate. The laminate was then exposed outdoors (Koka City, Shiga Prefecture) for two years with the surface of the sheet-like specimen perpendicular to the horizontal. The surface condition of the sheet-like specimen was visually observed three months, one year, or two years after exposure and evaluated according to the following criteria. The results are shown in the "Stain Resistance" columns in Table 2, "3 Months Later," "1 Year Later," and "2 Years Later," respectively. ○: No adhesion of contaminants such as dust or sand and no rain streak stains were observed. △: There was a slight adhesion of contaminants such as dust and sand and rain streaks. There is no problem in actual use. ×: Contaminants such as dust and sand adhere to the surface and rain streaks occur. It was in a pretty dirty state.

[0154] [Table 1]

[0155] [Table 2] [Industrial Applicability]

[0156] The curable composition of the present invention exhibits excellent contamination resistance after curing and can maintain excellent rubber elasticity for a long period of time, and therefore can be suitably used, for example, as a filler for joints formed between exterior wall members that constitute the exterior walls of building structures.

Claims

1. The composition contains 100 parts by mass of an organic polymer (I) having a hydrolyzable silyl group, 15 to 40 parts by mass of a (meth)acrylic acid ester-based polymer (B) containing a (meth)acrylic acid ester unit having a polyoxyethylene chain, a fluoroalkyl compound (C), and a silanol condensation catalyst (D), The organic polymer (I) having a hydrolyzable silyl group does not have a (meth)acrylic acid ester unit containing a fluoroalkyl group and a polyoxyethylene chain, The (meth)acrylic acid ester polymer (B) does not have a fluoroalkyl group, The (meth)acrylic acid ester polymer (B) is a polymer of acrylic monomers including a (meth)acrylic acid ester containing a polyoxyethylene chain, a (meth)acrylic acid alkyl ester, and a (meth)acrylic acid ester containing a hydrolyzable silyl group, and the content of the (meth)acrylic acid ester units containing the polyoxyethylene chain is 10% by mass or more and less than 50% by mass, The (meth)acrylic acid ester containing a polyoxyethylene chain is a (meth)acrylic acid ester represented by the following general formula (1): The fluoroalkyl compound (C) is a surfactant having a fluoroalkyl group, or a curable composition characterized in that it is a polymer containing a (meth)acrylic acid ester unit represented by the following formula (2), a monomer unit having a hydrophilic group and a polymerizable unsaturated group, and a (meth)acrylic acid alkyl ester unit in which the alkyl group has 1 to 8 carbon atoms: 【Chemistry 1】 In formula (1), R 2 is a hydrogen atom or a methyl group, R 3 is a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 24 carbon atoms, a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, or a substituted or unsubstituted aralkyl group having 7 to 20 carbon atoms, and m is an integer from 2 to 100. 【Chemistry 2】 In formula (2), R 6 is a perfluoroalkyl group having 1 to 6 carbon atoms, R 7 is a hydrogen atom or a methyl group, and Z 1 is a single bond or a divalent organic group.

2. 2. The curable composition according to claim 1, wherein the organic polymer (I) having a hydrolyzable silyl group contains a polyalkylene oxide (A) having a hydrolyzable silyl group.

3. 3. The curable composition according to claim 2, wherein the polyalkylene oxide (A) has a number average molecular weight of 20,000 or more and 50,000 or less, and a molecular weight distribution of 1.3 or less.

4. The curable composition according to any one of claims 1 to 3, wherein the content of (meth)acrylic acid ester units containing polyoxyethylene chains in the (meth)acrylic acid ester-based polymer (B) is 10 mass% or more and less than 50 mass%.

5. The curable composition according to any one of claims 1 to 4, wherein the mass ratio of the organic polymer (I) having a hydrolyzable silyl group to the fluoroalkyl compound (C) [mass of the organic polymer (I) having a hydrolyzable silyl group / mass of the fluoroalkyl compound (C)] is 25 or more and 50 or less.

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