JP7723399B2 - Curable compositions, sealants and adhesives - Google Patents

Description

The present invention relates to a curable composition that cures in the presence of atmospheric moisture to produce a cured product that exhibits excellent antifouling properties over a long period of time, as well as to sealants and adhesives made using the same.

Curable compositions containing oxyalkylene polymers having crosslinkable hydrolyzable silyl groups have been known for some time (Patent Document 1). The crosslinkable hydrolyzable silyl groups in the curable compositions are hydrolyzed by moisture in the atmosphere, followed by dehydration condensation, resulting in a cured product with excellent adhesiveness.

Such curable compositions are used, for example, in the exterior walls of building structures, by filling the joints (so-called "joints") between exterior wall components such as mortar boards, concrete boards, ALC (Autoclaved Lightweight Concrete) boards, and metal plates to join them together. Using the curable composition in this way prevents rainwater from seeping into the interior of the building structure through the joints between the exterior wall components.

In the exterior walls of building structures, exterior wall components expand and contract with temperature changes, and they move due to vibrations caused by earthquakes or strong winds or external forces, causing slight changes in the width of joints. For this reason, curable compositions are required to have excellent rubber elasticity after curing and be expandable and contractible so that they can follow changes in joint width.

In recent years, the surfaces of exterior wall components that make up the exterior walls of building structures have sometimes been treated with anti-fouling treatments. In such cases, the exterior wall components are less susceptible to dirt, allowing the exterior wall to maintain its beautiful appearance for a long period of time. However, the cured product of the curable composition filled into the joints has not been treated with anti-fouling treatment. Furthermore, the cured product of the curable composition is designed to be highly flexible so that it can adapt to changes in the width of the joints. In such cases, tack remains on the surface of the cured product of the curable composition, which allows dirt to adhere to the surface of the cured product due to dust and contaminants. This has led to the problem of impaired appearance when viewed as a whole exterior wall. Therefore, there is a demand for cured products of curable compositions that can also exhibit long-term anti-fouling effects.

Patent Document 2 discloses that the use of a diamine compound makes the surface of the cured product of the curable composition hydrophilic, thereby providing an anti-fouling effect through a self-cleaning action. However, diamine compounds are unable to provide excellent anti-fouling effects over a long period of time.

Patent Document 3 discloses that the use of a fluorine-containing surfactant in addition to a diamine compound can make the surface of the cured product of the curable composition more hydrophilic, improving the antifouling effect through its self-cleaning action. However, the use of a fluorine-containing surfactant significantly increases the price, making it impractical from a cost perspective.

Japanese Patent Application Publication No. 2008-1833 Japanese Patent Application Laid-Open No. 2004-059870 Japanese Patent Application Publication No. 2008-291159

In addition, curable compositions containing diamine compounds have the problem of reflecting sunlight and other light when the cured surface of the composition is observed obliquely, resulting in gloss. In such cases, the color tone of the cured surface changes depending on the observation angle, which can be unpleasant for the observer and result in poor appearance. For this reason, it is necessary to impart anti-fouling properties to the cured product of the curable composition while reducing gloss.

The inventors' research has revealed that the combined use of a monoamine compound and a diamine compound reduces the gloss generated by the curable composition after curing and enables it to exhibit excellent antifouling properties over a long period of time. However, depending on the combination of monoamine compound and diamine compound, the color difference between the curable composition before and after curing can be large. For example, there are cases where the color difference (ΔE) between the curable composition in the early stages of curing after application and the curable composition that has completely or almost completely cured is large. In such cases, it may not be possible to achieve the desired color tone in the cured product of the curable composition. Therefore, it is also necessary to minimize the color difference between the cured composition before and after curing.

The present invention therefore provides a curable composition that exhibits a small color difference before and after curing, reduces gloss after curing, and provides excellent anti-fouling properties over a long period of time.

The curable composition of the present invention is characterized by comprising a polymer (I) having a hydrolyzable silyl group, which includes a polyalkylene oxide (A) having a hydrolyzable silyl group; a monoamine compound (C); and a diamine compound, which includes a diamine compound (D) having a melting point equal to or lower than the melting point of the monoamine compound (C).

[Polymer (I)]
The curable composition includes a polymer (I) having a hydrolyzable silyl group. The polymer (I) having a hydrolyzable silyl group makes it possible to provide a moisture-curable composition that can be cured by atmospheric moisture.

(Polyalkylene oxide (A))
The polymer (I) having a hydrolyzable silyl group contains a polyalkylene oxide (A) having a hydrolyzable silyl group. The polyalkylene oxide (A) has a hydrolyzable silyl group.

A hydrolyzable silyl group is a group formed by bonding one to three hydrolyzable groups to a silicon atom. The hydrolyzable groups of the hydrolyzable silyl group are not particularly limited, and examples include hydrogen atoms, halogen atoms, alkoxy groups, acyloxy groups, ketoximate groups, amino groups, amide groups, acid amide groups, aminooxy groups, mercapto groups, and alkenyloxy groups.

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

The polyalkylene oxide (A) preferably has 1 to 3, and more preferably 1 to 2, hydrolyzable silyl groups on average per molecule. When the main chain of the polyalkylene oxide (A) is linear, the polyalkylene oxide (A) preferably has 1 to 2 hydrolyzable silyl groups on average per molecule. When the main chain of the polyalkylene oxide (A) is branched, the polyalkylene oxide (A) preferably has 1 to 3 hydrolyzable silyl groups on average per molecule. When the number of hydrolyzable silyl groups in the polyalkylene oxide (A) is 1 or more, the curability of the curable composition is improved. When the number of hydrolyzable silyl groups in the polyalkylene oxide (A) is equal to or less than the above upper limit, 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 the two ends of its main chain.

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

Preferred examples of the polyalkylene oxide (A) include polymers whose main chain contains repeating units represented by the general formula: -(R ¹ -O) _n - (wherein R ¹ represents an alkylene group having 1 to 14 carbon atoms, and n represents the number of repeating units and is a positive integer.) The main chain skeleton of the polyalkylene oxide (A) may consist of only one type of repeating unit, or may consist of two or more types of repeating units.

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. Of these, polypropylene oxide is preferred. Polypropylene oxide can provide a curable composition that exhibits excellent rubber elasticity and adhesive properties after curing.

The number average molecular weight of the polyalkylene oxide (A) is preferably 15,000 to 50,000, and more preferably 16,000 to 30,000. When the number average molecular weight of the polyalkylene oxide (A) is 15,000 or more, the mechanical strength or elongation 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.

In the present invention, the number average molecular weight of polyalkylene oxide (A) refers to the polystyrene-equivalent value measured by GPC (gel permeation chromatography). When measuring by GPC, for example, a Tosoh Shodex KF800D GPC column and chloroform or the like can be used as the solvent.

Commercially available polyalkylene oxides (A) containing hydrolyzable silyl groups can be used. For example, examples of polyalkylene oxides (A) having a polypropylene oxide main chain skeleton and methyldimethoxysilyl groups at the ends of the main chain skeleton include those manufactured by Asahi Glass Co., Ltd. under the trade names "Excestar S4530," "Excestar S2730C," and "Excestar S2420."

The content of polyalkylene oxide (A) in polymer (I) having a hydrolyzable silyl group is preferably 20 to 100% by mass, more preferably 30 to 80% by mass, more preferably 40 to 70% by mass, and particularly preferably 55 to 70% by mass. By keeping the content of polyalkylene oxide (A) within the above range, the flexibility of the cured product of the curable composition is improved.

(Acrylic polymer (B))
The polymer (I) having a hydrolyzable silyl group preferably further contains an acrylic polymer (B) having a hydrolyzable silyl group. By using the acrylic polymer (B), the cured product of the curable composition can maintain excellent rubber elasticity for a long period of time.

The hydrolyzable silyl group contained in the acrylic polymer (B) is preferably an alkoxysilyl group, as this allows the cured product of the curable composition to maintain excellent rubber elasticity over a long period of time. Examples of alkoxysilyl groups 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. Of these, dialkoxysilyl and trialkoxysilyl groups are more preferred, with trialkoxysilyl groups being even more preferred, and trimethoxysilyl groups being particularly preferred.

The main chain skeleton of the acrylic polymer (B) can be an acrylic polymer obtained by radical polymerization of a (meth)acrylate monomer such as ethyl (meth)acrylate or butyl (meth)acrylate. Note that (meth)acrylate refers to methacrylate or acrylate.

Specific examples of (meth)acrylate monomers that constitute the main chain of acrylic polymer (B) include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate, tert-butyl (meth)acrylate, cyclohexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, isononyl (meth)acrylate, and isomyristyl (meth)acrylate. Acrylate, stearyl (meth)acrylate, isobornyl (meth)acrylate, benzyl (meth)acrylate, 2-butoxyethyl (meth)acrylate, 2-phenoxyethyl (meth)acrylate, glycidyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, hexanediol di(meth)acrylate, ethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, trimethylene glycol di(meth)acrylate, Examples of the acrylates include tyrolpropane tri(meth)acrylate, pentaerythritol di(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, epoxy(meth)acrylate, polyester(meth)acrylate, urethane(meth)acrylate, 2-hydroxyethyl(meth)acrylate, 3-hydroxypropyl(meth)acrylate, 2-hydroxypropyl(meth)acrylate, 4-hydroxybutyl(meth)acrylate, 2-hydroxybutyl(meth)acrylate, 5-hydroxypentyl(meth)acrylate, 6-hydroxyhexyl(meth)acrylate, 3-hydroxy-3-methylbutyl(meth)acrylate, 2-hydroxy-3-phenoxypropyl(meth)acrylate, 2-[acryloyloxy]ethyl-2-hydroxyethyl phthalate, and 2-[acryloyloxy]ethyl-2-hydroxypropyl phthalate. These (meth)acrylate monomers may be used alone or in combination of two or more.

It is also possible to copolymerize other monomers in the acrylic polymer (B). Examples of such monomers include styrene derivatives such as styrene, indene, α-methylstyrene, p-methylstyrene, p-chlorostyrene, p-chloromethylstyrene, p-methoxystyrene, p-tert-butoxystyrene, and divinylbenzene; compounds having a vinyl ester group such as vinyl acetate, vinyl propionate, vinyl butyrate, vinyl caproate, vinyl benzoate, and vinyl cinnamate; maleic anhydride, N-vinylpyrrolidone, N-vinylmorpholine, (meth)acrylonitrile, (meth)acrylamide, N-cyclohexylmaleimide, N-phenylmaleimide, N-laurylmaleimide, N-benzylmaleimide, n-propyl vinyl ether, n-butyl vinyl ether, isobutyl vinyl ether, tert-butyl vinyl ether, tert-amyl vinyl ether, cyclohexyl vinyl ether, 2-ethylhexyl vinyl ether, dodecyl vinyl ether, octadecyl vinyl ether, 2-chloroethyl vinyl ether, ethylene glycol butyl vinyl ether, and triethylene glycol butyl vinyl ether. Examples of vinyloxy group-containing compounds include glycol methyl vinyl ether, (4-vinyloxy)butyl benzoate, ethylene glycol divinyl ether, diethylene glycol divinyl ether, triethylene glycol divinyl ether, tetraethylene glycol divinyl ether, butane-1,4-diol divinyl ether, hexane-1,6-diol divinyl ether, cyclohexane-1,4-dimethanol divinyl ether, di(4-vinyloxy)butyl isophthalate, di(4-vinyloxy)butyl glutarate, di(4-vinyloxy)butyl succinate, trimethylolpropane trivinyl ether, 2-hydroxyethyl vinyl ether, 4-hydroxybutyl vinyl ether, 6-hydroxyhexyl vinyl ether, cyclohexane-1,4-dimethanol monovinyl ether, diethylene glycol monovinyl ether, 3-aminopropyl vinyl ether, 2-(N,N-diethylamino)ethyl vinyl ether, urethane vinyl ether, and polyester vinyl ether. These monomers may be used alone or in combination.

Among these, the main chain skeleton of the acrylic polymer (B) is preferably a copolymer of butyl (meth)acrylate and methyl (meth)acrylate, and more preferably a copolymer of butyl acrylate and methyl methacrylate. Acrylic polymer (B) whose main chain skeleton is composed of the above copolymer can produce a curable composition that can form a cured product that exhibits both extensibility and flexibility after curing.

The polymerization method for the acrylic polymer (B) is not particularly limited, and known methods can be used, including various polymerization methods such as free radical polymerization, anionic polymerization, cationic polymerization, UV radical polymerization, living anionic polymerization, living cationic polymerization, and living radical polymerization.

The method for introducing hydrolyzable silyl groups into the acrylic polymer (B) is not particularly limited, and known methods can be used, such as hydrosilylation by reacting a hydrosilane having a hydrolyzable silyl group with an acrylic polymer having an unsaturated group introduced into the molecule.

The number average molecular weight of the acrylic polymer (B) is preferably 1,000 to 50,000, and more preferably 2,000 to 30,000. When the number average molecular weight of the acrylic polymer (B) is 50,000 or less, the coatability of the curable composition is improved. When the number average molecular weight of the acrylic polymer (B) is 1,000 or more, the mechanical strength or elongation of the cured product of the curable composition is improved.

In the present invention, the number average molecular weight of the acrylic polymer (B) refers to a value calculated in terms of polystyrene as measured by gel permeation chromatography (GPC). When measuring by GPC, for example, a Tosoh Shodex KF800D GPC column and chloroform or the like can be used as a solvent.

The content of the acrylic polymer (B) in the polymer (I) having a hydrolyzable silyl group is preferably 20 to 70% by mass, more preferably 30 to 60% by mass, and particularly preferably 30 to 45% by mass. When the content of the acrylic polymer (B) is 20% by mass or more, the cured product of the curable composition maintains excellent rubber elasticity over a long period of time. When the content of the acrylic polymer (B) is 70% by mass or less, the coatability of the curable composition is improved.

[Monoamine Compound (C)]
The curable composition of the present invention contains a monoamine compound (C). In the present invention, the monoamine compound refers to a compound having one amino group (—NH ₂ ) per molecule. In the monoamine compound, the hydrogen atom of the amino group may be substituted with an organic group such as an alkyl group or an aryl group. Furthermore, it is preferable that the monoamine compound (C) does not contain a silicon atom.

In the curable composition of the present invention, the combined use of monoamine compound (C) and diamine compound reduces the occurrence of gloss after curing and enables the composition to exhibit excellent antifouling effects over a long period of time.

The melting point of the monoamine compound (C) is preferably 65°C or lower, more preferably 20 to 65°C, even more preferably 25 to 65°C, and particularly preferably 40 to 50°C. By setting the melting point of the monoamine compound (C) to 65°C or lower, the monoamine compound (C) can easily migrate to the surface of the cured product of the curable composition. This reduces the generation of gloss after curing and makes it possible to provide a curable composition that exhibits excellent anti-fouling effects over a long period of time. Furthermore, by setting the melting point of the monoamine compound (C) to 20°C or higher, the generation of tack on the surface of the cured product of the curable composition can be reduced.

When the curable composition contains multiple types of monoamine compounds (C), the melting point of the monoamine compounds (C) refers to the melting point of each monoamine compound (C).

The melting point of monoamine compound (C) refers to the temperature measured by differential scanning calorimetry (DSC) in accordance with JIS K7121 (1987). For example, monoamine compound (C) is heated using a differential scanning calorimeter (such as the DSC-60 manufactured by Shimadzu Corporation), and the melting peak temperature of the DSC curve during this heating process is taken as the melting point of monoamine compound (C). Conditioning of the test specimen is performed in accordance with JIS K7121 (1987) 3. (1). If there are multiple melting peaks, the temperature at the apex of the melting peak with the greatest endothermic heat is taken as the melting point.

Preferred examples of the monoamine compound (C) include monoamine compounds represented by the following formula (1):
R ² —NH ₂ (1)
(In formula (1), ^R2 is a linear or branched alkyl group or a monovalent saturated alicyclic hydrocarbon group.)

In formula (1), ^R2 is preferably a linear or branched alkyl group. Examples of the linear or branched alkyl group for ^R2 include decyl, isodecyl, undecyl, lauryl, isododecyl, tridecyl, myristyl, pentadecyl, palmityl, heptadecyl, isohexadecyl, stearyl, isooctadecyl, nonadecyl, eicosyl, and behenyl groups.

In the monoamine compound (C) represented by formula (1), the number of carbon atoms in ^R2 is preferably 12 to 40, more preferably 15 to 30, and particularly preferably 15 to 25. By using a monoamine compound (C) in which the number of carbon atoms in ^R2 falls within the above range, the tackiness of the surface of a cured product of the curable composition can be reduced in a short period of time, and the cured product of the curable composition can exhibit excellent antifouling effect over a long period of time.

Specific examples of the monoamine compound (C) include behenylamine ( _{C22H45 - NH2} , melting point 63°C), stearylamine ( _{C18H37 - NH2} , melting point 50°C), cetylamine ( _{C16H33 - NH2} , melting point 47°C), myristylamine ( _C14H29 - _NH2 , melting point 38°C ₎ , and _{laurylamine (C12H25-NH2 , melting} point 28°C). Of these, behenylamine and stearylamine are preferred. The monoamine compound (C) may be used alone or in combination of two or more.

The content of the monoamine compound (C) in the curable composition is preferably 0.1 to 20 parts by mass, more preferably 0.5 to 10 parts by mass, more preferably 0.5 to 5 parts by mass, and particularly preferably 1 to 5 parts by mass, per 100 parts by mass of the polymer (I) having a hydrolyzable silyl group. When the content of the monoamine compound (C) is 0.1 part by mass or more, the surface of the cured product of the curable composition can exhibit excellent antifouling effects over a long period of time. Furthermore, when the content of the monoamine compound (C) is 20 parts by mass or less, the occurrence of tack on the surface of the cured product of the curable composition at high temperatures can be reduced.

[Diamine compound]
The curable composition of the present invention contains a diamine compound. In the present invention, a diamine compound refers to a compound having two amino groups (—NH ₂ ) in one molecule. In the diamine compound, the hydrogen atoms of the amino groups may be substituted with organic groups such as alkyl groups or aryl groups. In addition, it is preferable that the diamine compound does not contain silicon atoms.

The diamine compound includes a diamine compound (D) having a melting point equal to or lower than the melting point of the monoamine compound (C). By using such a diamine compound (D), it is possible to provide a curable composition that has a small color difference before and after curing and exhibits reduced gloss after curing.

When the curable composition contains multiple types of diamine compounds, the melting point of the diamine compounds refers to the melting point of each diamine compound.

Furthermore, in relation to "diamine compound (D) having a melting point equal to or lower than that of monoamine compound (C)," when multiple types of monoamine compounds (C) are used, the diamine compound having a melting point equal to or lower than the melting point (P _Low ) of the monoamine compound (C _Low ) having the lowest melting point (P _Low ) among the multiple types of monoamine compounds (C) is defined as "diamine compound (D)."

In the present invention, the melting point of a diamine compound refers to the temperature measured by differential scanning calorimetry (DSC) in accordance with JIS K7121 (1987). For example, a diamine compound is heated using a differential scanning calorimetry device (such as the DSC-60 manufactured by Shimadzu Corporation), and the melting peak temperature of the DSC curve during this heating process is taken as the melting point of the diamine compound. Conditioning of the test specimen is performed in accordance with JIS K7121 (1987) 3. (1). When there are multiple melting peaks, the temperature at the apex of the melting peak with the greatest endothermic heat is taken as the melting point.

The melting point of the diamine compound (D) is preferably 65°C or lower, more preferably -1 to 65°C, more preferably 30 to 65°C, even more preferably 35 to 65°C, and particularly preferably 40 to 65°C. By setting the melting point of the diamine compound (D) to 65°C or lower, the diamine compound (D) can easily migrate to the surface of the cured product of the curable composition. This reduces gloss after curing and provides a curable composition that exhibits excellent antifouling properties over a long period of time. Furthermore, by setting the melting point of the diamine compound (D) to -1°C or higher, the occurrence of tack on the surface of the cured product of the curable composition can be significantly reduced, thereby maintaining excellent antifouling properties. In particular, by setting the melting point of the diamine compound (D) to 30°C or higher, the occurrence of tack on the surface of the cured product of the curable composition can be significantly reduced, even at high temperatures such as in summer, and excellent antifouling properties can be maintained. The diamine compound (D) may be used alone or in combination of two or more types.

In the curable composition, the mass ratio of the monoamine compound (C) to the diamine compound (D) [mass of the monoamine compound (C):mass of the diamine compound (D)] is preferably 1:9 to 9:1, more preferably 2:8 to 8:2, and even more preferably 3:7 to 7:3. When the mass ratio of the monoamine compound (C) to the diamine compound (D) is within the above range, it is possible to provide a curable composition that reduces gloss generation after curing and is capable of exhibiting excellent antifouling effects over a long period of time.

The content of diamine compound (D) in the diamine compound is preferably 40% by mass or more, more preferably 50% by mass or more, and particularly preferably 90 to 100% by mass. By keeping the content of diamine compound (D) within the above range, it is possible to provide a curable composition that has a smaller color difference before and after curing and exhibits reduced gloss after curing.

The diamine compound may further contain a diamine compound (E) having a melting point higher than that of the monoamine compound (C), as long as it does not adversely affect the properties of the curable composition. The content of diamine compound (E) in the diamine compound is preferably 60% by mass or less, more preferably 50% by mass or less, and particularly preferably 0 to 10% by mass. A lower content of diamine compound (E) can provide a curable composition with a smaller color difference before and after curing and reduced gloss generation after curing.

In relation to the "diamine compound (E) having a melting point higher than that of the monoamine compound (C)," when multiple types of monoamine compounds (C) are used, the diamine compound having a melting point higher than the melting point (P _High ) of the monoamine compound (C _High ) having the highest melting point (P _High ) among the multiple types of monoamine compounds (C) is defined as "diamine compound (E)."

The diamine compound is preferably a diamine compound represented by the following formula (2).
R ³ -NH-R ⁴ -NH ₂ (2)
(In formula (2), ^R3 is a linear or branched alkyl group, an unsaturated aliphatic hydrocarbon group, a monovalent saturated alicyclic hydrocarbon group, or an aryl group, and ^R4 is an alkylene group.)

In formula (2), examples of the linear or branched alkyl group for ^R3 include a decyl group, an isodecyl group, an undecyl group, a lauryl group, an isododecyl group, a tridecyl group, a myristyl group, a pentadecyl group, a palmityl group, a heptadecyl group, an isohexadecyl group, a stearyl group, an isooctadecyl group, a nonadecyl group, an eicosyl group, and a behenyl group. Examples of the unsaturated aliphatic hydrocarbon group for ^R3 include an undecenyl group, a cis-4-tetradecenyl group, a cis-5-tetradecenyl group, a cis-9-tetradecenyl group, a cis-6-hexadecenyl group, a palmitoleyl group, a cis-6-octadecenyl group, an oleyl group, a trans-9-octadecenyl group, a cis-11-octadecenyl group, a trans-11-octadecenyl group, a myristoleyl group, a palmitoleyl group, and a linoleyl group.

In formula (2), ^R4 is an alkylene group. Examples of the alkylene group for ^R4 include a methylene group, an ethylene group, an ethylidene group, a trimethylene group, a propylene group, an isopropylene group, a tetramethylene group, a butylene group, an isobutylene group, a pentylene group, a hexamethylene group, and a hexylene group.

In the diamine compound represented by formula (2), the total number of carbon atoms in ^R3 and ^R4 is preferably 15 to 40, more preferably 15 to 30, and particularly preferably 15 to 25. By setting the total number of carbon atoms in ^R3 and ^R4 within the above range, the surface of the cured product of the curable composition can exhibit excellent antifouling effect for a long period of time, and the occurrence of tack on the surface of the cured product of the curable composition at high temperatures can be greatly reduced.

Specific examples of diamine compounds include behenyl propylene diamine (C ₂₂ H ₄₅ —NH—C ₃ H ₆ —NH ₂ , melting point 63° C.) and oleyl propylene diamine (C ₁₈ H ₃₅ —NH—C ₃ H ₆ —NH _{2 ,} melting point 20° C.), with behenyl propylene diamine being preferred.

The content of the diamine compound in the curable composition is preferably 0.1 to 20 parts by mass, more preferably 0.5 to 10 parts by mass, and particularly preferably 1 to 5 parts by mass, per 100 parts by mass of the polymer (I) having a hydrolyzable silyl group. When the content of the diamine compound is 0.1 part by mass or more, the surface of the cured product of the curable composition can exhibit excellent antifouling effects over a long period of time. Furthermore, when the content of the diamine compound is 20 parts by mass or less, the occurrence of tack on the surface of the cured product of the curable composition at high temperatures can be reduced.

[Plasticizer]
The curable composition preferably further contains a plasticizer, specific examples of which 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.

It is preferable that the acrylic polymer used as a plasticizer does not contain hydrolyzable silyl groups.

Examples of the main chain skeleton of acrylic polymers used as plasticizers include acrylic polymers obtained by radical polymerization of (meth)acrylate monomers.

Specific examples of (meth)acrylate monomers that make up the main chain of acrylic polymers used as plasticizers include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate, tert-butyl (meth)acrylate, cyclohexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, isononyl (meth)acrylate, and isomyristyl (meth)acrylate. methyl (meth)acrylate, stearyl (meth)acrylate, isobornyl (meth)acrylate, benzyl (meth)acrylate, 2-butoxyethyl (meth)acrylate, 2-phenoxyethyl (meth)acrylate, glycidyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, hexanediol di(meth)acrylate, ethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate , trimethylolpropane tri(meth)acrylate, pentaerythritol di(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, epoxy(meth)acrylate, polyester(meth)acrylate, urethane(meth)acrylate, 2-hydroxyethyl(meth)acrylate, 3-hydroxypropyl(meth)acrylate, 2-hydroxypropyl(meth)acrylate Examples of suitable (meth)acrylate monomers include acrylate, 4-hydroxybutyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 5-hydroxypentyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 3-hydroxy-3-methylbutyl (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, 2-[acryloyloxy]ethyl-2-hydroxyethyl phthalate, and 2-[acryloyloxy]ethyl-2-hydroxypropyl phthalate. These (meth)acrylate monomers may be used alone or in combination of two or more.

The weight-average molecular weight of the acrylic polymer used as a plasticizer is preferably 1,000 to 50,000, and more preferably 2,000 to 30,000. When the weight-average molecular weight of the acrylic polymer used as a plasticizer is 50,000 or less, the coatability of the curable composition is improved. When the weight-average molecular weight of the acrylic polymer used as a plasticizer is 1,000 or more, the mechanical strength or elongation of the cured product of the curable composition is improved.

In the present invention, the weight-average molecular weight of the acrylic polymer used as a plasticizer refers to the polystyrene-equivalent value measured by GPC (gel permeation chromatography). When measuring by GPC, for example, a Tosoh Shodex KF800D GPC column and chloroform or the like can be used as the solvent.

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, more preferably 1 to 70 parts by mass, and particularly preferably 20 to 50 parts by mass, per 100 parts by mass of the polymer (I) having a hydrolyzable silyl group. If the content of the plasticizer is too high, the plasticizer may precipitate on the surface of the cured product of the curable composition.

[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.

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. These fillers may be used alone or in combination. Of these, calcium carbonate is preferred.

The average particle size of calcium carbonate is preferably 0.01 to 5 μm, and more preferably 0.05 to 2.5 μm. Calcium carbonate with such an average particle size can produce a cured product with excellent mechanical strength and elongation, and can also provide a curable composition with excellent adhesive properties.

The calcium carbonate is preferably surface-treated with a fatty acid, a fatty acid ester, or the like. Calcium carbonate that has been surface-treated with a fatty acid, a fatty acid ester, or the like can impart thixotropy to the hardenable composition and inhibit aggregation of the calcium carbonate.

The content of the filler in the curable composition is preferably 1 to 700 parts by mass, and more preferably 10 to 200 parts by mass, per 100 parts by mass of the polymer (I) having a hydrolyzable silyl group. When the content of the filler is 1 part by mass or more, the effect of adding the filler is fully obtained. Furthermore, when the content of the filler is 700 parts by mass or less, the cured product obtained by curing the curable composition has excellent elongation.

[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.

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. Of these, vinyltrimethoxysilane is preferred.

The content of the dehydrating agent in the curable composition is preferably 0.5 to 20 parts by mass, and more preferably 1 to 15 parts by mass, per 100 parts by mass of the polymer (I) having a hydrolyzable silyl group. When the content of the dehydrating agent is 0.5 parts by mass or more, the effect of the dehydrating agent is fully obtained. Furthermore, when the content of the dehydrating agent is 20 parts by mass or less, the curable composition has excellent curability.

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

Silanol condensation catalysts include organotin compounds such as 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 organotitanium compounds such as tetra-n-butoxytitanate and tetraisopropoxytitanate. These silanol condensation catalysts may be used alone or in combination.

A preferred silanol condensation catalyst is 1,1,3,3-tetrabutyl-1,3-dilauryloxycarbonyl-distannoxane. Using such a silanol condensation catalyst makes it easy to adjust the curing rate of the curable composition.

The content of the silanol condensation catalyst in the curable composition is preferably 1 to 10 parts by mass, and more preferably 1 to 5 parts by mass, per 100 parts by mass of the polymer (I) having a hydrolyzable silyl group. When the content of the silanol condensation catalyst is 1 part by mass or more, the curing rate of the curable composition can be increased, thereby shortening the time required for curing the curable composition. When the content of the silanol condensation catalyst 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.

[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.

[Thixotropy-imparting agent]
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.

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

[Ultraviolet absorber]
Examples of the ultraviolet absorber include a benzotriazole-based ultraviolet absorber and a benzophenone-based ultraviolet absorber, and the benzotriazole-based ultraviolet absorber is preferred. The content of the ultraviolet absorber in the curable composition is preferably 0.1 to 20 parts by mass, more preferably 0.1 to 10 parts by mass, per 100 parts by mass of the polymer (I) having a hydrolyzable silyl group.

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

[Light stabilizer]
The curable composition preferably contains a hindered amine light stabilizer, which can provide a curable composition that can maintain excellent rubber elasticity for a longer period of time after curing.

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-piperidylsebacate, 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- Examples include polycondensates of dimethyl succinate and 4-hydroxy-2,2,6,6-tetramethyl-1-piperidineethanol, poly[{6-(1,1,3,3-tetramethylbutyl)amino-1,3,5-triazine-2,4-diyl}{(2,2,6,6-tetramethyl-4-piperidyl)imino}hexamethylene{(2,2,6,6-tetramethyl-4-piperidyl)imino}], and polycondensates of dimethyl succinate and 4-hydroxy-2,2,6,6-tetramethyl-1-piperidineethanol.

Preferred examples of hindered amine light stabilizers include NOR-type hindered amine light stabilizers. NOR-type hindered amine light stabilizers can provide a curable composition that inhibits loss of rubber elasticity over time after curing.

NOR-type hindered amine light stabilizers have an NOR structure in which an alkyl group (R) is bonded to a nitrogen atom (N) contained in a piperidine ring skeleton via an oxygen atom (O). The alkyl group in the NOR structure preferably has 1 to 20 carbon atoms, more preferably 1 to 18, and particularly preferably 18. Examples of the alkyl group include linear alkyl groups, branched alkyl groups, and cyclic alkyl groups (saturated alicyclic hydrocarbon groups).

Examples of linear alkyl groups include methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-octyl, n-nonyl, and n-decyl groups. Examples of branched alkyl groups include isopropyl, isobutyl, sec-butyl, and tert-butyl groups. Examples of cyclic alkyl groups (saturated alicyclic hydrocarbon groups) include cyclopentyl, cyclohexyl, and cyclooctyl groups. Furthermore, the hydrogen atoms constituting the alkyl group may be substituted with halogen atoms (e.g., fluorine, chlorine, and bromine atoms) or hydroxyl groups.

NOR-type hindered amine light stabilizers include those represented by the following formula (I):

When using a NOR-type hindered amine light stabilizer, it is preferable to use it in combination with a benzotriazole-based UV absorber or a triazine-based UV absorber. This makes it possible to provide a curable composition in which the decrease in rubber elasticity over time after curing is more significantly suppressed.

The content of the hindered amine light stabilizer in the curable composition is preferably 0.01 to 20 parts by mass, and more preferably 0.1 to 10 parts by mass, per 100 parts by mass of the polymer (I) having a hydrolyzable silyl group.

[Aminosilane coupling agent]
The curable composition of the present invention preferably contains an aminosilane coupling agent. By using the aminosilane coupling agent, the rubber elasticity and adhesiveness of the cured product of the curable composition can be improved. The aminosilane coupling agent means a compound containing a silicon atom to which an alkoxy group is bonded and a functional group containing a nitrogen atom in one molecule.

Specific examples of aminosilane coupling agents 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. These aminosilane coupling agents may be used alone or in combination.

Among these, preferred examples of the aminosilane coupling agent include 3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, and N-(2-aminoethyl)-3-aminopropyltriethoxysilane, and more preferred example is N-(2-aminoethyl)-3-aminopropyltrimethoxysilane.

The content of the aminosilane coupling agent in the curable composition is preferably 1 to 10 parts by mass, and more preferably 1 to 5 parts by mass, per 100 parts by mass of the polymer (I) having a hydrolyzable silyl group. When the content of the aminosilane coupling agent is within the above range, the rubber elasticity and adhesiveness of the cured product of the curable composition can be improved.

The curable composition of the present invention has excellent adhesive properties and can form a cured product that maintains excellent rubber elasticity over a long period of time, making it suitable for a variety of applications, including sealants, coating materials, adhesives, and paints.

In particular, the curable composition of the present invention has a small color difference before and after curing, making it easy to adjust to the desired color after curing. For example, it is possible to reduce the color difference (ΔE) between a curable composition in the early stages of curing after application and a curable composition that has completely or nearly completely cured. Furthermore, the curable composition of the present invention has an anti-fouling effect while reducing the occurrence of gloss due to reflection of light such as sunlight, and therefore can maintain a beautiful appearance for a long period of time, especially when used outdoors. Therefore, the curable composition of the present invention is preferably used as a sealant or adhesive, and more preferably as a sealant for joint structures.

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

The joints are not particularly limited, but examples include joints in the exterior walls, interior walls, and ceilings of building structures. The curable composition of the present invention can maintain excellent stain-resistant properties for an extended period of time after curing. Therefore, it is suitable for sealing so-called "working joints," such as joints in the exterior walls of building structures, which are prone to staining due to dust and pollutants.

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

The curable composition of the present invention has the above-described structure, which results in a small color difference before and after curing, reduced gloss after curing, and excellent stain resistance over a long period of time. Therefore, the cured product of the curable composition can be given the desired color tone and can maintain a beautiful appearance over a long period of time.

The present invention will be explained in more detail below using examples, but the present invention is not limited to these.

The following raw materials were used in producing the curable compositions of the Examples and Comparative Examples.
[Polymer (I) having a hydrolyzable silyl group]
(Polyalkylene oxide (A) having a hydrolyzable silyl group)
Polyalkylene oxide (A1) (a polyalkylene oxide having methyldimethoxysilyl groups and a polypropylene oxide main chain skeleton, manufactured by Asahi Glass Co., Ltd., trade name "Excestar S2420", average number of methyldimethoxysilyl groups per molecule: 1.7, molecular weight distribution: 1.49, number average molecular weight: 18,990)

(Acrylic polymer (B) having hydrolyzable silyl group)
Acrylic polymer (B1) (an acrylic polymer having a main chain skeleton formed from a methyl methacrylate-n-butyl acrylate copolymer (methyl methacrylate component content: 25% by mass, n-butyl acrylate component content: 75% by mass) and having a trimethoxysilyl group at the end of the main chain skeleton or in a side chain, number average molecular weight: 2,400)

[Monoamine Compound (C)]
Monoamine compound (C1) (stearylamine, melting point 50°C, product name "Farmin 80S" manufactured by Kao Corporation)
Monoamine compound (C2) (behenylamine, melting point 63°C, product name "Nissanamine VB-S" manufactured by NOF Corporation)

[Diamine compound]
-Hydrogenated beef tallow propylene diamine (manufactured by NOF Corporation, product name "Nissan Amine DT-H")
Behenyl propylene diamine (melting point 63°C, product name "Nissan Amine DV" manufactured by NOF Corporation)

The above-mentioned hardened beef tallow propylene diamine (trade name "Nissanamine DT-H", manufactured by NOF Corporation) contained 45 to 51 mass% of a diamine compound represented by the above formula (2) (in formula (2), R ³ is a linear alkyl group having 15 to 18 carbon atoms and R ⁴ is a propylene group) and having a melting point of 64 to 80°C, 1 to 4 mass% of a diamine compound represented by the above formula (2) (in formula (2), R ³ is a linear alkyl group having 13 to 14 carbon atoms and R ⁴ is a propylene group) and having a melting point of 53 to 60°C, and 45 to 51 mass% of a diamine compound represented by the above formula (2) (in formula (2), R ³ is an unsaturated aliphatic hydrocarbon group having 15 to 18 carbon atoms and R ⁴ is a propylene group) and having a melting point of -1 to 28°C.

[Plasticizer]
Plasticizer (1) (acrylic polymer not having a hydrolyzable silyl group, weight average molecular weight: 3,500, manufactured by Toagosei Co., Ltd., product name "UP-1110")

[Filler]
Colloidal calcium carbonate (average particle size: 80 nm, surface treatment with fatty acid, manufactured by Maruo Calcium Co., Ltd., product name "Calcine 200M")
Heavy calcium carbonate (average particle size: 1.0 μm, surface treated with fatty acid, manufactured by Nitto Funka Co., Ltd., product name "NCC2310")

[Dehydrating agent]
Vinyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., product name "KBM-1003")

[Silanol condensation catalyst]
Silanol condensation catalyst (1,1,3,3-tetrabutyl-1,3-dilauryloxycarbonyl-distannoxane, manufactured by Nitto Kasei Co., Ltd., trade name "Neostan U-130")

[Ultraviolet absorber]
Benzotriazole-based ultraviolet absorber (manufactured by BASF Japan Ltd., product name "Tinuvin 326")

[Antioxidants]
- Hindered phenol-based antioxidant (manufactured by BASF Japan, product name "Irganox 1010")

[Light stabilizer]
NH-type hindered amine light stabilizer (manufactured by BASF Japan Ltd., product name "Tinuvin 770")

[Other additives]
Aminosilane coupling agent (N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, product name "KBM-603" manufactured by Shin-Etsu Chemical Co., Ltd.)
Thixotropic agent (fatty acid amide wax, manufactured by Kusumoto Chemicals Co., Ltd., product name "Disparlon #6500")
)

[solvent]
・Ethylene glycol tertiary butyl ether (ETB)

(Examples 1 to 4, Comparative Examples 1 to 8)
[0111] The polyalkylene oxide (A1), acrylic polymer (B1), monoamine compound (C1), monoamine compound (C2), hardened beef tallow propylene diamine, behenyl propylene diamine, plasticizer (1), colloidal calcium carbonate, heavy calcium carbonate, vinyltrimethoxysilane, silanol condensation catalyst, benzotriazole-based ultraviolet absorber, hindered phenol-based antioxidant, NH-type hindered amine-based light stabilizer, aminosilane coupling agent, thixotropic agent, and ethylene glycol tertiary butyl ether (ETB) were mixed in the amounts shown in Table 1 in a sealed stirrer under reduced pressure until the mixture was uniform, thereby obtaining a curable composition.

[evaluation]
The resulting curable compositions were evaluated for gloss, color difference, and antifouling effect immediately after curing and after a long-term exposure test according to the following procedures.

[Glossiness]
The curable composition was applied to a stainless steel plate to a thickness of 5 mm in an atmosphere of 23°C and 50% relative humidity, and then aged for one day. The gloss was measured using a gloss meter (manufactured by Tasco Japan Co., Ltd., product name "Gloss Checker TMS724") when light was incident at an angle of incidence of 20 degrees or 60 degrees onto the cured surface of the curable composition, and evaluated according to the following criteria. The results are shown in Table 1. Note that a smaller gloss value indicates a lower light reflectance and a lower gloss of the cured surface.
Good: The gloss level was 3 or less.
×: Glossiness was greater than 3.

[Color difference]
The curable composition was applied to a thickness of 5 mm under an atmosphere of 23°C and 50% relative humidity and aged for 8 hours to obtain a sheet-like cured product (I). Separately, the curable composition was applied to a thickness of 5 mm under an atmosphere of 23°C and 50% relative humidity and aged for 14 days to obtain a sheet-like cured product (II). Colorimetry measurements of the surfaces of the cured products (I) and (II) were performed in accordance with JIS K5600-4-5 (1999) using a spectrophotometer (manufactured by Konica Minolta Japan, Inc., product name "CM-2500d"). The color difference (ΔE) between the cured products (I) and (II) was calculated in accordance with JIS K5600-4-6 (1999) and evaluated according to the following criteria. The results are shown in Table 1.
Good: The color difference (ΔE) was less than 2.0.
×: The color difference (ΔE) was 2.0 or more.

[Anti-fouling effect (immediately after curing)]
The curable composition was applied to a stainless steel plate to a thickness of 5 mm in an atmosphere of 23°C and 50% relative humidity and then cured for one day. No. 7 silica sand was sprinkled on the surface of the cured curable composition, and the presence or absence of silica sand was visually observed and evaluated based on the following criteria. The results are shown in the "Anti-fouling effect (immediately after curing)" column in Table 1.
◎: No silica sand adhered.
◯: The number of silica sand particles adhering per 5 cm square was 1 particle or more and less than 50 particles.
. . . The number of silica sand particles adhering per 5 cm square was 50 or more and less than 200 particles.
×: The number of silica sand particles adhering per 5 cm square was 200 or more.

[Anti-fouling effect (after long-term exposure test)]
A 5 mm thick coating of the curable composition was applied to a release-treated polyethylene terephthalate (PET) substrate at 23°C and 50% relative humidity, and the coating was then aged for one day. A sheet-like test 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 test specimen, and the sheet-like test specimen alone was attached to an aluminum plate to obtain a laminate. The laminate was then exposed outdoors (Koka City, Shiga Prefecture) for three months, with the surface of the sheet-like test specimen facing north at a 45-degree inclination angle relative to the horizontal. After exposure, the degree of adhesion of dirt such as dust and sand to the surface of the sheet-like test specimen was visually observed and evaluated according to the following criteria. The results are shown in the "Anti-fouling effect (after long-term exposure test)" column in Table 1.
⊚: No dirt was attached.
○: Although there was a small amount of dirt, the condition was good.
△: Although there is some dirt, it does not cause any problems in practical use.
×: The entire surface was covered with dirt and was in a very dirty state.

[Table 1]

The curable composition of the present invention has a small color difference before and after curing, reduces gloss after curing, and maintains excellent stain-resistant properties over a long period of time. Therefore, it can be suitably used, for example, as a filler for joints formed between exterior wall components that make up the exterior walls of building structures.

Claims (6)

A curable composition comprising a polymer (I) having a hydrolyzable silyl group, which includes a polyalkylene oxide (A) having a hydrolyzable silyl group, a monoamine compound (C) represented by ^R2 - _NH2 , and a diamine compound (D) having a melting point equal to or lower than that of the monoamine compound (C) and represented by ^R3 -NH- ^R4 - _NH2 , wherein ^R2 is a linear or branched alkyl group or a monovalent saturated alicyclic hydrocarbon group, ^R3 is a linear or branched alkyl group, an unsaturated aliphatic hydrocarbon group, a monovalent saturated alicyclic hydrocarbon group, or an aryl group, and ^R4 is an alkylene group. The curable composition according to claim 1, characterized in that the polymer (I) having a hydrolyzable silyl group contains an acrylic polymer (B) having a hydrolyzable silyl group. The curable composition according to claim 1 or 2, characterized in that the melting point of the monoamine compound (C) is 65°C or lower. 4. The curable composition according to claim 1, wherein a mass ratio of the monoamine compound (C) to the diamine compound (D) [mass of the monoamine compound (C):mass of the diamine compound (D)] is 1:9 to 9 :1. A sealant containing the curable composition described in any one of claims 1 to 4. An adhesive containing the curable composition described in any one of claims 1 to 4.