JP2022013783A - Curable composition - Google Patents

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

The present invention relates to a curable composition that cures by moisture in an atmosphere (air) to provide a cured product that exhibits excellent stain resistance and can maintain excellent rubber elasticity for a long period of time. ..

Conventionally, a curable composition containing an oxyalkylene polymer having a crosslinkable hydrolyzable silyl group has been known (for example, Patent Document 1). The curable composition produces a cured product having excellent adhesiveness by dehydrating and condensing after the hydrolyzable silyl group that can be crosslinked by the moisture contained in the atmosphere is hydrolyzed.

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.

Such a curable composition is, for example, in an outer wall of a building structure, a joint portion (so-called "joint") between outer wall members such as a mortar plate, a concrete plate, an ALC (Autoclaved Light-weight Concrete) plate, and a metal plate. ) Is used to join the outer wall members to each other. By using the curable composition in this way, it is possible to prevent rainwater from entering the inside of the building structure from the joint between the outer wall members.

In the outer wall of a building structure, the joint width changes slightly because the outer wall member expands or contracts with a temperature change, or the outer wall member moves due to vibration or external force caused by an earthquake or strong wind. Therefore, it is required that the curable composition has excellent rubber elasticity after curing and is made expandable so that it can firmly adhere to the outer wall and follow the change in joint width.

Japanese Patent No. 5698422 Japanese Patent No. 32123370

However, there is a problem that contaminants such as dust and sand adhere to the surface of the cured product of the curable composition over time and the appearance is impaired. In addition, contaminants also cause rain streaks on the surface of the cured product of the curable composition. Rain streak stains are streaky traces formed by pollutants such as dust and sand adhering to the surface of the cured product of the curable composition flowing down the surface of the cured product together with rainwater. The generation of such rain streak stains also impairs the appearance of the cured product surface of the curable composition. Therefore, the curable composition is required to have excellent stain resistance so that the adhesion of contaminants and the generation of rain streak stains can be reduced after curing to maintain a beautiful appearance.

According to the study of the present inventor, it has been found that the use of the fluoroalkyl compound can impart excellent stain resistance to the cured product of the curable composition. As a result of further studies by the present inventor based on such findings, it has been found that the durability of the cured product of the curable composition is lowered when the fluoroalkyl compound is used. When the durability of the cured product of the curable composition is reduced, the rubber elasticity of the cured product of the curable composition changes over time due to the contact of the cured product of the curable composition with moisture in the air or water such as rainwater. It becomes difficult for the cured product to expand and contract in accordance with the change in the joint width between the outer wall members. When the rubber elasticity of the cured product of the curable composition is lowered in this way, the cured product of the curable composition is peeled off from the adhesive interface with the outer wall member, or the outer wall member is damaged, and as a result, rainwater is constructed. Problems such as intrusion into the structure and causing water leakage occur.

Therefore, an object of the present invention is to provide a curable composition capable of exhibiting excellent stain resistance after curing and maintaining excellent rubber elasticity for a long period of time.

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

(Organic polymer (I) having a hydrolyzable silyl group (I))
The curable composition of the present invention contains an organic polymer (I) having a hydrolyzable silyl group. In the organic polymer (I) containing a hydrolyzable silyl group, the hydrolyzable group of the hydrolyzable silyl group is hydrolyzed in the presence of water to generate a silanol group (-SiOH). Then, the silanol groups are dehydrated and condensed to form a crosslinked structure.

The organic polymer (I) having a hydrolyzable silyl group is not particularly limited, and for example, a polyalkylene oxide having a hydrolyzable silyl group, an acrylic polymer having a hydrolyzable silyl group, and a hydrolyzable silyl. Examples thereof include a silicone resin having a group, a urethane resin having a hydrolyzable silyl group, and a polyolefin resin 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. According to the polyalkylene oxide (A) having a hydrolyzable silyl group, the adhesiveness of the curable composition can be improved. The organic polymer (I) having a hydrolyzable silyl group preferably does not have 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.

The polyalkylene oxide (A) preferably does not have a fluoroalkyl group. Further, the polyalkylene oxide (A) preferably does not contain a (meth) acrylic acid ester unit containing a polyoxyethylene chain. That is, it is preferable that the polyalkylene oxide (A) does not contain a (meth) acrylic acid ester containing a polyoxyethylene chain as a monomer component.

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 is, for example, 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, or a mercapto. Groups, alkenyloxy groups and the like can be mentioned.

Among them, as the hydrolyzable silyl group of the polyalkylene oxide (A), an alkoxysilyl group is preferable because the hydrolysis reaction is mild. The alkoxysilyl group includes a trialkoxysilyl group such as a trimethoxysilyl group, a triethoxysilyl group, a triisopropoxysilyl group, and a triphenoxysilyl group; a dialkoxysilyl group such as a methyldimethoxyryl group and a methyldiethoxysilyl group. Groups; as well as monoalkoxysilyl groups such as dimethylmethoxysilyl group and dimethylethoxysilyl group. Of these, a dialkoxysilyl group is more preferable, and a methyldimethoxysilyl group is particularly preferable.

The polyalkylene oxide (A) preferably has 1 to 2 hydrolyzable silyl groups in one molecule on average. When the number of hydrolyzable silyl groups in the polyalkylene oxide (A) is one or more, the curability of the curable composition is improved. Further, when the number of hydrolyzable silyl groups in the polyalkylene oxide (A) is 2 or less, the mechanical strength or extensibility of the cured product of the curable composition is improved. Further, the polyalkylene oxide (A) preferably has a hydrolyzable silyl group at at least one of both ends of the molecular chain.

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

As the polyalkylene oxide (A), the main chain has a general formula:-(R ¹ -O) _n- (in the formula, R ¹ represents an alkylene group having 1 to 14 carbon atoms, and n is a repeating unit. A polymer containing a repeating unit represented by a number and a positive integer) is preferably mentioned. The main clavicle of the polyalkylene oxide may consist of only one repeating unit or may consist of two or more repeating units.

Examples of the main chain skeleton of polyalkylene oxide (A) include polyethylene oxide, polypropylene oxide, polybutylene oxide, polytetramethylene oxide, polyethylene oxide-polypropylene oxide copolymer, and polypropylene oxide-polybutylene oxide copolymer. Be done. Of these, polypropylene oxide is preferable. According to polypropylene oxide, it is possible to provide a curable composition having excellent rubber elasticity and adhesiveness after curing.

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.

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.

In the present invention, the number average molecular weight and the weight average molecular weight of the polyalkylene oxide mean the polystyrene-converted values measured by the GPC (gel permeation chromatography) method.

Specifically, 6 to 7 mg of polyalkylene oxide is collected, and the collected polyalkylene oxide is supplied to a test tube. A solution of orthodichlorobenzene (o-DCB) containing 0.05% by mass of dibutylhydroxytoluene (BHT) is prepared, and this solution is added to a test tube to dilute the concentration of polyalkylene oxide to 1 mg / mL. To prepare a diluted solution. Using a dissolution filtration device, the diluted solution is shaken at 145 ° C. and a rotation speed of 25 rpm for 1 hour to dissolve the polyalkylene oxide in the solution and use it as a measurement sample. Using this measurement sample, the number average molecular weight and the weight average molecular weight of the polyalkylene oxide can be measured by the GPC method.

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

As the polyalkylene oxide (A) containing a hydrolyzable silyl group, a commercially available product can be used. For example, examples of the polyalkylene oxide having a main chain skeleton of polypropylene oxide and a methyldimethoxysilyl group at the end of the main chain skeleton include the product name “Exester ESS 4530” manufactured by AGC Inc.

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 100% by mass. % Is particularly preferable. That is, it is particularly preferable that the organic polymer (I) having a hydrolyzable silyl group consists only 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.

((Meta) Acrylic Acid Ester Polymer (B))
The curable composition comprises a (meth) acrylic acid ester-based polymer (B) containing a (meth) acrylic acid ester unit containing a polyoxyethylene chain. By using such a (meth) acrylic acid ester-based polymer (B) in combination with a fluoroalkyl compound (C) described later, excellent stain resistance is exhibited after curing, and excellent rubber elasticity is exhibited. It is possible to provide a curable composition that can be maintained for a long period of time. The (meth) acrylic acid ester-based polymer (B) preferably does not have a fluoroalkyl group.

The (meth) acrylic acid ester-based polymer (B) contains a (meth) acrylic acid ester unit containing a polyoxyethylene chain. It is preferable that the main chain skeleton of the (meth) acrylic acid ester-based polymer (B) is a polymer of an acrylic-based monomer containing a (meth) acrylic acid ester containing a polyoxyethylene chain.

The (meth) acrylic acid ester containing a polyoxyethylene chain preferably does not have a hydrolyzable silyl group. The (meth) acrylic acid means acrylic acid or methacrylic acid.

As the (meth) acrylic acid ester containing a polyoxyethylene chain, a (meth) acrylic acid ester represented by the following general formula (1) is preferably mentioned.

（式中、Ｒ²は水素原子又はメチル基であり、Ｒ³は、水素原子、炭素数が１～２４である置換あるいは非置換のアルキル基、炭素数が６～２０である置換あるいは非置換のアリール基、又は炭素数が７～２０である置換あるいは非置換のアラルキル基であり、ｍは２から１００の整数である。）

(In the formula, 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, and a substituted or unsubstituted group having 6 to 20 carbon atoms. Is an aryl group of, or a substituted or unsubstituted aralkyl group having 7 to 20 carbon atoms, and m is an integer of 2 to 100.)

R ² in the formula (1) is preferably a hydrogen atom or a methyl group, and more preferably a methyl group.

M in the formula (1) is the number of repeating units, and an integer of 2 or more is preferable, an integer of 3 or more is more preferable, and an integer of 4 or more is particularly preferable. On the other hand, for m in the formula (1), an integer of 100 or less is preferable, an integer of 40 or less is more preferable, an integer of 30 or less is more preferable, and an integer of 15 or less is particularly preferable.

R ³ in the formula (1) is a substituted or unsubstituted alkyl group having 1 to 24 carbon atoms, a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, and a substitution having 7 to 20 carbon atoms. Alternatively, an unsubstituted aralkyl group is preferable.

The substituted or unsubstituted alkyl group having 1 to 24 carbon atoms in R ³ of the formula (1) may be linear or branched chain, and is not particularly limited. Examples of the unsubstituted alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an amyl group and an isoamyl group. , Tert-amyl group, neopentyl group, n-hexyl group and the like. The hydrogen atom contained in these alkyl groups may be substituted with an organic group such as a hydroxy group and an alkoxy group. The aryl group is preferably removed from the organic group. Examples of the substituted alkyl group include a hirodoxyalkyl group and an alkoxyalkyl group. The substituted alkyl group preferably excludes an aralkyl group such as a benzyl group.

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

The substituted or unsubstituted aralkyl group having 7 to 20 carbon atoms in R ³ of the formula (1) includes a benzyl group, α, α-phenylmethylbenzyl group, α, α-dimethylbenzyl group, α, α-. Methylphenylbenzyl group, α-naphthylmethyl group, 1-α-naphthylethyl group, 2-α-naphthylethyl group, 1-α-naphthylisopropyl group, 2-α-naphthylisopropyl group, β-naphthylmethyl group, 1 Examples thereof include -β-naphthylethyl group, 2-β-naphthylethyl group, 1-β-naphthylisopropyl group, 2-β-naphthylisopropyl group and the like.

As R ³ of the formula (1), a hydrogen atom and a substituted or unsubstituted alkyl group having 1 to 24 carbon atoms are preferable, and an unsubstituted alkyl group having 1 to 10 carbon atoms is more preferable, and carbon. An unsubstituted alkyl group having a number of 1 to 3 is particularly preferable.

The alcohol residue forming the (meth) acrylic acid ester containing a polyoxyethylene chain is preferably a polyethylene glycol residue whose end is sealed with an alkyl group having 1 to 24 carbon atoms.

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

The content of the (meth) acrylic acid ester unit containing a polyoxyethylene chain in the (meth) acrylic acid ester-based polymer (B) is preferably 10% by mass or more, more preferably 20% by mass or more, and 25% by mass. % Or more is particularly preferable. On the other hand, the content of the (meth) acrylic acid ester unit containing the polyoxyethylene chain in the (meth) acrylic acid ester-based polymer (B) is preferably less than 50% by mass, more preferably 45% by mass or less. When the content of the (meth) acrylic acid ester unit containing the polyoxyethylene chain is 10% by mass or more, a good self-cleaning effect by water can be imparted to the surface of the cured product of the curable composition. When the content of the (meth) acrylic acid ester unit containing the polyoxyethylene chain is less than 50% by mass, the durability of the cured product of the curable composition is improved. This makes it possible to reduce the decrease in rubber elasticity of the cured product of the curable composition due to contact with water.

The (meth) acrylic acid ester-based polymer (B) preferably contains a (meth) acrylic acid alkyl ester unit. The main chain skeleton of the (meth) acrylic acid ester-based polymer (B) is an acrylic monomer containing a (meth) acrylic acid ester unit containing a polyoxyethylene chain and a (meth) acrylic acid alkyl ester unit. It is more preferable that it is a polymer of. By using the (meth) acrylic acid alkyl ester, the durability of the cured product of the curable composition is improved. The (meth) acrylic acid alkyl ester preferably does not contain a polyoxyethylene chain. The (meth) acrylic acid alkyl ester preferably does not have a hydrolyzable silyl group. The hydrogen in the alkyl group of the (meth) acrylic acid alkyl ester is not substituted.

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

The content of the (meth) acrylic acid alkyl ester unit 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 the (meth) acrylic acid alkyl ester unit 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 the (meth) acrylic acid alkyl ester unit is 30% by mass or more, the durability of the cured product of the curable composition is improved. When the content of the (meth) acrylic acid alkyl ester unit is less than 90% by mass, the workability of the curable composition is improved.

The (meth) acrylic acid ester-based polymer (B) preferably has a hydrolyzable silyl group. According to the (meth) acrylic acid ester-based polymer (B) having a hydrolyzable silyl group, the cured product of the curable composition can maintain excellent rubber elasticity for a long period of time.

As the hydrolyzable silyl group of the (meth) acrylic acid ester polymer (B), an alkoxysilyl group can be used because the cured product of the curable composition can maintain excellent rubber elasticity for a long period of time. preferable. The alkoxysilyl group includes a triethoxysilyl group such as a trimethoxysilyl group, a triethoxysilyl group, a triisopropoxysilyl group, and a triphenoxysilyl group; a dimethoxysilyl group such as a methyldimethoxysilyl group and a methyldiethoxysilyl group. ; Also, monoalkoxysilyl groups such as a dimethylmethoxysilyl group and a dimethylethoxysilyl group can be mentioned. Of these, a dialkoxysilyl group and a trialkoxyryl group are more preferable, a trialkoxysilyl group is more preferable, and a trimethoxysilyl group is particularly preferable.

The (meth) acrylic acid ester-based 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-based polymer (B) contains a (meth) acrylic acid ester containing a polyoxyethylene chain and a (meth) acrylic acid ester containing a hydrolyzable silyl group. It is more preferably a polymer of an acrylic monomer, and contains a (meth) acrylic acid ester containing a polyoxyethylene chain, a (meth) acrylic acid alkyl ester, and a (meth) hydrolyzable silyl group. It is more preferable that it is a polymer of an acrylic monomer containing an acrylic acid ester.

The (meth) acrylic acid ester containing a hydrolyzable silyl group is not particularly limited, and is, for example, (meth) acrylic acid 3- (trimethoxysilyl) propyl, (meth) acrylic acid 3- (triethoxysilyl). Propyl, 3- (methyldimethoxysilyl) propyl (meth) acrylate, 2- (trimethoxysilyl) ethyl (meth) acrylate, 2- (triethoxysilyl) ethyl (meth) acrylate, 2 (meth) acrylate -(Methyldimethoxysilyl) ethyl, (meth) acrylate trimethoxysilylmethyl, (meth) acrylate triethoxysilylmethyl, (meth) acrylate (methyldimethoxysilyl) methyl and the like can be mentioned. Of these, 3- (trimethoxysilyl) propyl (meth) acrylate and 3- (methyldimethoxysilyl) propyl (meth) acrylate are preferable, and 3- (trimethoxysilyl) propyl (meth) acrylate is more preferable. 3- (Trimethoxysilyl) propyl methacrylate is particularly preferred. The (meth) acrylic acid ester containing a hydrolyzable silyl group may be used alone or in combination of two or more. Esters in which the hydrogen of the alkyl group of the (meth) acrylic acid alkyl ester is replaced with a hydrolyzable silyl group are in the category of (meth) acrylic acid alkyl ester because the hydrogen of the alkyl group is replaced by another atomic group. Is not included in.

The content of the (meth) acrylic acid ester unit containing a hydrolyzable silyl group in the (meth) acrylic acid ester-based polymer (B) is preferably 0.5% by mass or more, more preferably 1% by mass or more. .. On the other hand, the content of the (meth) acrylic acid ester unit containing a hydrolyzable silyl group in the (meth) acrylic acid ester-based polymer (B) is preferably 10% by mass or less, more preferably 7% by mass or less. .. When the content of the (meth) acrylic acid ester unit 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 makes it possible to reduce the decrease in rubber elasticity of the cured product of the curable composition due to contact with water. When the content of the (meth) acrylic acid ester unit containing a hydrolyzable silyl group is 10% by mass or less, the rubber elasticity of the cured product of the curable composition is improved.

The (meth) acrylic acid ester-based polymer (B) may contain a (meth) acrylic acid-substituted alkyl ester unit. The (meth) acrylic acid substituted alkyl ester is a hydrogen atom contained in the alkyl group of the (meth) acrylic acid alkyl ester, which is an alkoxy group, a hydroxy group, a halogen atom (fluorine atom, chlorine atom, etc.), or a fluoroalkyl group. , Means a compound substituted with an organic group such as an amino group.

Examples of the (meth) acrylic acid substituted alkyl ester include (meth) acrylic acid 2-methoxyethyl, (meth) acrylic acid 3-methoxybutyl, (meth) acrylic acid 2-hydroxyethyl, and (meth) acrylic acid 2-. Hydroxypropyl, (meth) acrylic acid 2,2,2-trifluoroethyl, (meth) acrylic acid 3,3,3-trifluoropropyl, (meth) acrylic acid 3,3,4,4,4-pentafluoro Butyl, 2-perfluoroethyl (meth) acrylate-2-perfluorobutyl ethyl, trifluoromethyl (meth) acrylate, perfluoroethyl (meth) acrylate, bis (trifluoromethyl) methyl (meth) acrylate , (Meta) acrylate 2-trifluoromethyl-2-perfluoroethyl ethyl, (meth) acrylate 2-perfluorohexyl ethyl, (meth) acrylate 2-perfluorodecylethyl, (meth) acrylate 2- Examples thereof include perfluorohexadecylethyl, dimethylaminoethyl (meth) acrylate, 2-chloroethyl (meth) acrylate, and 2-aminoethyl (meth) acrylate. The (meth) acrylic acid substituted alkyl ester may be used alone or in combination of two or more.

The (meth) acrylic acid ester-based polymer (B) includes (meth) acrylic acid, (meth) phenyl acrylate, (meth) toluyl acrylate, benzyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, and the like. It may contain other acrylic monomer units.

The method for synthesizing the (meth) acrylic acid ester-based polymer (B) is not particularly limited, and examples thereof include known methods. For example, various polymerization methods such as a free radical polymerization method, an anion polymerization method, a cationic polymerization method, a UV radical polymerization method, a living anion polymerization method, a living cationic polymerization method, and a living radical polymerization method can be mentioned.

For example, as a free radical polymerization method, 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. A solution polymerization method in which a polymerization initiator, a chain transfer agent, a solvent, etc. are added to an acrylic monomer containing the above and the acrylic monomer is polymerized at 50 to 150 ° C. Examples thereof include a continuous massive polymerization method described in Japanese Patent Publication No. 2001-207157, which polymerizes at high temperature and high pressure.

The reaction is usually initiated using an oil-soluble radical initiator as the polymerization initiator. Examples of the oil-soluble radical initiator include azo-based polymerization initiators and organic peroxides.

The azo-based polymerization initiator is not particularly limited, and is, for example, 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-methylpropion Amid], 1,1'-azobis (cyclohexane-1-carbonitrile) and the like.

The organic peroxide is not particularly limited, and for example, benzoyl peroxide, isobutylyl peroxide, isononanoyl peroxide, decanoyle peroxide, lauroyl peroxide, parachlorobenzoyl peroxide, and di (3, 5, 5). -Diacyl peroxides such as (trimethylhexanoyl) peroxide; diisopropylperoxydicarbonate, di-sec-butylperoxydicarbonate, di-2-ethylhexylperoxydicarbonate, di-1-methylheptylperoxydicarbonate, di-1-methylheptylperoxydicarbonate, di-1-methylheptylperoxydicarbonate. Peroxydicarbonates such as -3-methoxybutylperoxydicarbonate, dicyclohexylperoxydicarbonate; tert-butylperoxybenzoate, tert-butylperoxyacetate, tert-butylperoxy-2-ethylhexanoate, tert- Peroxyesters such as butylperoxyisobutyrate, tert-butylperoxypivalate, tert-butyldiperoxyadipate, cumylperoxyneodecanoate; ketone peroxides such as methylethylketone peroxide and cyclohexanone peroxide; -Dialkyl peroxides such as tert-butyl peroxide, dicumyl peroxide, tert-butyl cumyl peroxide, 1,1-di (tert-hexylperoxy) -3,3,5-trimethylcyclohexane; cumenehydroxyperoxide , Hydroperoxides such as tert-butylhydroperoxide; 1,1-di (tert-hexylperoxy) -3,3,5-trimethylcyclohexane and the like. When a peroxide is used as the radical polymerization initiator, it may be used in combination with a reducing agent as a redox type polymerization initiator. The polymerization initiator may be used alone or in combination of two or more.

Examples of the chain transfer agent include mercapto group-containing compounds such as n-dodecyl mercaptan, tert-dodecyl mercaptan, and lauryl mercaptan. When a hydrolyzable silyl group is to be introduced at the end of the molecular chain of the (meth) acrylic acid ester-based polymer (B), examples of the chain transfer agent include 3-mercaptopropyltrimethoxysilane and 3-mercapto. Examples thereof include propylmethyldimethoxysilane, 3-mercaptopropylchloromethyldimethoxysilane, 3-mercaptopropylmethoxymethyldimethoxysilane, mercaptomethyltrimethoxysilane, and (mercaptomethyl) dimethoxymethylsilane. The chain transfer agent may be used alone or in combination of two or more. Since the chain transfer agent may adversely affect the weather resistance, the amount used is preferably 2% or less of the total amount of the monomer, and it is particularly preferable not to use the chain transfer agent.

Examples of the solvent include aromatic compounds such as toluene, xylene, styrene, ethylbenzene, paradichlorobenzene, di-2-ethylhexyl phthalate and di-n-butyl phthalate; hexane, heptane, octane, cyclohexane, methylcyclohexane and the like. Hydrocarbon compounds; Carboxylic acid ester compounds such as butyl acetate, n-propulate and isopropyl acetate; Ketone compounds such as methyl isobutyl ketone and methyl ethyl ketone; Dialkyl carbonate compounds such as dimethyl carbonate and diethyl carbonate; 1-propanol and 2-propanol. , 1-butanol, 2-butanol, isobutanol, tert-butyl alcohol, amyl alcohol and other alcohol compounds can be mentioned. Of these, dimethyl carbonate, 1-propanol, 2-propanol, 1-butanol, 2-butanol, isobutanol and tert-butyl alcohol are more preferable, and 2-propanol and isobutanol are particularly preferable.

The weight average molecular weight of the (meth) acrylic acid ester-based 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-based 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-based 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-based polymer (B) is 30,000 or less, good workability of the curable composition can be maintained.

In the present invention, the weight average molecular weight of the (meth) acrylic acid ester-based polymer (B) means a polystyrene-converted value measured by a GPC (gel permeation chromatography) method. In the measurement by the GPC method, for example, Shodex KF800D manufactured by Tosoh can be used as the GPC column, and chloroform or the like can be used as the solvent.

The content of the (meth) acrylic acid ester-based polymer (B) in the curable composition is preferably 5 parts by mass or more with respect to 100 parts by mass of the organic polymer (I) having a hydrolyzable silyl group. 10 parts by mass or more is more preferable, and 15 parts by mass or more is particularly preferable. On the other hand, the content of the (meth) acrylic acid ester-based polymer (B) in the curable composition is 200 parts by mass or less with respect to 100 parts by mass of the organic polymer (I) having a hydrolyzable silyl group. Preferably, 100 parts by mass or less is more preferable, 75 parts by mass or less is more preferable, 65 parts by mass or less is more preferable, 60 parts by mass or less is more preferable, 55 parts by mass or less is more preferable, and 50 parts by mass or less is more preferable. 45 parts by mass or less is more preferable, and 40 parts by mass or less is more preferable. When the content of the (meth) acrylic acid ester-based 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-based polymer (B) is 200 parts by mass or less, the coatability of the curable composition is improved.

(Fluoroalkyl compound (C))
The curable composition of the present invention contains a fluoroalkyl compound (C). By using the fluoroalkyl compound (C), the surface of the cured product of the curable composition of the present invention can be made superhydrophilic. As a result, when water comes into contact with the surface of the cured product of the curable composition due to rainfall or the like, the water spreads thinly on the surface of the cured product without forming water droplets and can easily flow down. Therefore, even when a pollutant such as dust adheres to the surface of the cured product, the pollutant can be washed away together with water such as rainwater (self-cleaning action), and the adhesion of the pollutant can be reduced. Further, according to the fluoroalkyl compound (C), it is possible to reduce the occurrence of rain streak stains when the pollutants are washed away together with water such as rainwater. Therefore, the curable composition of the present invention can exhibit excellent stain resistance after curing, thereby reducing the adhesion of contaminants and the occurrence of rain streak stains on the surface of the cured product of the curable composition. A beautiful appearance can be maintained. Furthermore, by using the fluoroalkyl compound (C) in combination with the above-mentioned (meth) acrylic acid ester-based polymer (B), the cured product surface of the curable composition has excellent stain resistance over a long period of time. It will also be possible to maintain. The fluoroalkyl compound (C) may be used alone or in combination of two or more.

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

The number of carbon atoms of the fluoroalkyl group is preferably 1 or more, more preferably 2 or more, and more preferably 4 or more. The number of carbon atoms of the fluoroalkyl group is preferably 25 or less, more preferably 15 or less, and even more preferably 10 or less. Examples of the fluoroalkyl group include CF ₃ CH _2- , CF ₃ CF ₂ CH _2- , CF ₃ (CF ₂ ) ₂ CH _2- , CF ₃ (CF ₂ ) ₃ CH ₂ CH _2- , CF ₃ (CF 3). ₂ ) ₄ CH ₂ CH ₂ CH _2- , CF ₃ (CF ₂ ) ₄ CH _2- , CF ₃ (CF ₂ ) ₅ CH ₂ CH _2- , CF ₃ (CF ₂ ) ₅ CH ₂ CH ₂ CH _2- , And (CF ₃ ) ₂ CH- and the like.

Preferred examples of the fluoroalkyl compound (C) include a surfactant having a fluoroalkyl group. Examples of the surfactant include anionic surfactants, cationic surfactants, nonionic surfactants, and amphoteric surfactants depending on the structure of the hydrophilic portion, but nonionic surfactants are preferable. Nonionic surfactants are compounds that do not ionize when dissolved in water.

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 repetitions of the oxyalkylene unit in the polyoxyalkylene chain is preferably 2 or more, more preferably 6 or more. The number of repetitions of the oxyalkylene unit in the polyoxyalkylene chain is preferably 30 or less, more preferably 20 or less.

As the fluoroalkyl compound (C), a commercially available compound can be used. For example, product names "Surflon S-381, S-383, KH-40" manufactured by AGC Seimi Chemical Co., Ltd. may be mentioned.

The fluoroalkyl compound (C) includes 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 an alkyl group having 1 carbon number. A polymer (CA) containing up to 8 (meth) acrylic acid alkyl ester units can be preferably used.

However, in the 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. Is.

The polymer (CA) preferably used as the fluoroalkyl compound (C) contains the (meth) acrylic acid ester unit represented by the above formula (2). The (meth) acrylic acid ester unit represented by the formula (2) may be contained alone or in combination of two or more in the polymer (CA).

In formula (2), R ⁶ is a perfluoroalkyl group having 1 to 6 carbon atoms. A perfluoroalkyl group is an atomic group in which all hydrogen of the alkyl group is replaced with a fluorine atom. The perfluoroalkyl group having 1 to 6 carbon atoms may be linear or branched, but is preferably linear because the stain resistance of the curable composition after curing is improved. ..

In the perfluoroalkyl group, the alkyl group before hydrogen is replaced with a fluorine atom is a linear alkyl of a methyl group, an ethyl group, a propyl group, an n-butyl group, an n-pentyl group and an n-hexyl group. Examples thereof include branched alkyl groups such as a group, an isopropyl group, an isobutyl group, a sec-butyl group and a tert-butyl group.

The divalent organic group Z ¹ has -O-, -NH-, -CO-, -S-, -SO _2- , -CD ¹ = at the end between carbon atoms or on the side bonded to R ⁶ . It is preferable to use an alkylene group which may have CD ^2- (where D ¹ and D ² are independently hydrogen atoms or methyl groups).

As Z ¹ , for example, single bond, -CH _2- , -CH ₂ CH ₂ -,-(CH ₂ ) _3- , -CH (CH ₃ ) CH ₂ CH _2- , -CH ₂ -CH = CH- , -CH ₂ CH ₂ -S-, -CH ₂ CH ₂ -S-CH ₂ CH _2- , -CH ₂ CH ₂ -SO ₂ -CH ₂ CH _2- . Since the (meth) acrylic acid ester unit represented by the formula (2) has excellent stability, -CH ₂ CH ₂ -,-(CH ₂ ) _3- , -CH (CH ₃ ) CH ₂ CH _2- , etc. The alkylene group of is preferable.

Examples of the (meth) acrylic acid ester represented by the formula (2) include
CF ₃ CH ₂ OC (O) CH = CH ₂ ,
CF ₃ CH ₂ OC (O) C (CH ₃ ) = CH ₂ ,
C ₂ F ₅ CH ₂ OC (O) CH = CH ₂ ,
C ₂ F ₅ CH ₂ OC (O) C (CH ₃ ) = CH ₂ ,
CF ₃ CH ₂ CH ₂ OC (O) CH = CH ₂ ,
CF ₃ CH ₂ CH ₂ OC (O) C (CH ₃ ) = CH ₂ ,
C ₂ F ₅ CH ₂ CH ₂ OC (O) CH = CH ₂ ,
C ₂ F ₅ CH ₂ CH ₂ OC (O) C (CH ₃ ) = CH ₂ ,
C ₃ F ₇ CH ₂ CH ₂ OC (O) CH = CH ₂ ,
C ₃ F ₇ CH ₂ CH ₂ OC (O) C (CH ₃ ) = CH ₂ ,
C4F ₉ CH ₂ CH ₂ OC (O) CH = CH ₂ ,
C4F ₉ CH ₂ CH ₂ OC (O) C (CH ₃ ) = CH ₂ ,
C ₅ F ₁₁ CH ₂ CH ₂ OC (O) CH = CH ₂ ,
C ₅ F ₁₁ CH ₂ CH ₂ OC (O) C (CH ₃ ) = CH ₂ ,
C ₆ F ₁₃ CH ₂ CH ₂ OC (O) CH = CH ₂ ,
C ₆ F ₁₃ CH ₂ CH ₂ OC (O) C (CH ₃ ) = CH ₂
And so on.

As the (meth) acrylic acid ester represented by the formula (2), R ⁷ is a hydrogen atom or a methyl group, Z ¹ is -CH ₂ CH _2- , and R ⁶ is a perfluoroalkyl group having 2 to 6 carbon atoms. The (meth) acrylic acid ester is preferable because it has excellent stain resistance after curing of the curable composition.

The (meth) acrylic acid ester represented by the formula (2) is a (meth) acrylic acid ester in which Z ¹ is −CH ₂ CH ₂ − and R ⁶ is a perfluoroalkyl group having 6 carbon atoms, that is, C ₆ F ₁₃ CH ₂ CH ₂ OC (O) CH = CH ₂ or C ₆ F ₁₃ CH ₂ CH ₂ OC (O) C (CH ₃ ) = CH ₂ is more preferred, and C ₆ F ₁₃ CH ₂ CH ₂ OC (O) ) C (CH ₃ ) = CH ₂ is more preferable.

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 be contained alone or in combination of two or more in the polymer (CA).

The hydrophilic group is not particularly limited, and for example, an alkylene oxide group (-R ¹⁰ O-; R ¹⁰ is an alkylene group), an amino group, a hydroxy group, an acrylamide group (CH ₂ = CHCONH-), a carboxy group, and a phosphorus. Examples thereof include an acid group (-PO ₃ ^2- ), a sulfone group (-SO ₂ (OH)) and a quaternary ammonium salt. The alkylene group R ¹⁰ preferably has 1 to 5 carbon atoms, more preferably 1 to 3 carbon atoms.

The polymerizable unsaturated group is not particularly limited, and for example, CH ₂ = CH-, CH ₂ = CH-CH ₂ -O-, CH ₂ = CR ⁹ -C (= O) O-, CH ₂ = CR. ⁹ -OC (= O)-can be mentioned (where 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).

As the polymerizable unsaturated group, since it is excellent in rubber elasticity after curing in the curable composition, CH ₂ = CH-, CH ₂ = CH-CH ₂ -O-, CH ₂ = CH-C (= O). ) O-, CH ₂ = C (CH ₃ ) -C (= O) O-, CH ₂ = CH-OC (= O)-, CH ₂ = C (CH ₃ ) -OC (= O)- preferable.

Examples of the monomer having a hydrophilic group and a polymerizable unsaturated group include the following monomers.
CH ₂ = CH-C (= O) -O- (CH ₂ CH ₂ O) ₂ -H
CH ₂ = CH-C (= O) -O- (CH ₂ CH ₂ O) ₅ -H
CH ₂ = CH-C (= O) -O- (CH ₂ CH ₂ O) ₁₀ -H
CH ₂ = CH-C (= O) -O- (CH ₂ CH ₂ O) ₂₄ -H
CH ₂ = C (CH ₃ ) -C (= O) -O- (CH ₂ CH ₂ O) ₂ -H
CH ₂ = C (CH ₃ ) -C (= O) -O- (CH ₂ CH ₂ O) ₅ -H
CH ₂ = C (CH ₃ ) -C (= O) -O- (CH ₂ CH ₂ O) ₈ -H
CH ₂ = C (CH ₃ ) -C (= O) -O- (CH ₂ CH ₂ O) ₁₀ -H
CH ₂ = C (CH ₃ ) -C (= O) -O- (CH ₂ CH ₂ O) ₂₃ -H
CH ₂ = CH-C (= O) -O- (CH ₂ CH ₂ O) ₂ -OCH ₃
CH ₂ = CH-C (= O) -O- (CH ₂ CH ₂ O) ₄ -OCH ₃
CH ₂ = CH-C (= O) -O- (CH ₂ CH ₂ O) ₉ -OCH ₃
CH ₂ = CH-C (= O) -O- (CH ₂ CH ₂ O) ₁₀ -OCH ₃
CH ₂ = CH-C (= O) -O- (CH ₂ CH ₂ O) ₁₃ -OCH ₃
CH ₂ = C (CH ₃ ) -C (= O) -O- (CH ₂ CH ₂ O) ₂ -OCH ₃
CH ₂ = C (CH ₃ ) -C (= O) -O- (CH ₂ CH ₂ O) ₄ -OCH ₃
CH ₂ = C (CH ₃ ) -C (= O) -O- (CH ₂ CH ₂ O) ₉ -OCH ₃
CH ₂ = C (CH ₃ ) -C (= O) -O- (CH ₂ CH ₂ O) ₁₃ -OCH ₃
CH ₂ = C (CH ₃ ) -C (= O) -O- (CH ₂ CH ₂ O) ₂₃ -OCH ₃
CH ₂ = CH-C (= O) -OH
CH ₂ = C (CH ₃ ) -C (= O) -OH
CH ₂ = C (CH ₃ ) -C (= O) -CH ₂ -CH ₂ -NH ₃
CH ₂ = CH-C (= O) -CH ₂ -CH ₂ -NH ₃
CH ₂ = C (CH ₃ ) -C (= O) -N (CH ₃ ) ₂
CH ₂ = CH-C (= O) -N (CH ₃ ) ₂
CH ₂ = C (CH ₃ ) -C (= O) -N (CH ₂ CH ₂ OCH ₂ CH ₂ )
CH ₂ = CH-C (= O) -N (CH ₂ CH ₂ OCH ₂ CH ₂ )
CH ₂ = CH-C (= O) -NH- (CH ₂ ) ₃ -N ⁺ (CH ₃ ) ₃ · ^Cl-
And so on.

The polymer (CA) preferably has an alkylene oxide chain represented by-(R ¹¹ O) p-, as the stain resistance of the curable composition after curing is improved. p represents an integer from 1 to 30. The number of p (R ¹¹ O) may be one or more. R ¹¹ is an alkylene group, for example, an ethylene group, a propylene group [-CH (CH ₃ ) -CH _2- ], a trimethylene group [-CH ₂ -CH ₂ -CH _2- ], a butylene group, an amylene group [ -(CH ₂ ) _5- ], hexylene group and the like.

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- (CH ₂ CH ₂ O) qR ⁸ (3)
However, in the formula (3), Q ¹ is a monovalent substituent containing a polymerizable unsaturated group, Z ² is a single bond or a linear alkylene group having 1 to 10 carbon atoms, and R ⁸ is hydrogen. It is an atom or a methyl group, and q represents an integer of 1 to 30.

As Q ¹ , CH ₂ = CH-, CH ₂ = CH-CH ₂ -O-, CH ₂ = CR ⁹ -C (= O) O-, CH ₂ = CR ⁹ -OC (= O)-are preferable. (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 1 to 30, more preferably 4 to 26.

As the monomer represented by the formula (3), since the stain resistance of the curable composition after curing is improved, Q ¹ is CH ₂ = CR ⁹ -C (= O) O-, and R ⁹ is. A monomer having a hydrogen atom or a methyl group, Z ² as a single bond, R ⁸ as a methyl group, and q as 1 to 30 is preferable, and Q ¹ is CH ₂ = CH-C (= O) O-, More preferably, a monomer in which R ⁸ is a methyl group, Z ² is a single bond, and q is 4 to 26.

The polymer (CA) preferably used as the fluoroalkyl compound (C) contains a (meth) acrylic acid alkyl ester unit having an alkyl group having 1 to 8 carbon atoms. The (meth) acrylic acid alkyl ester unit may be contained alone or in combination of two or more in the polymer (CA). The hydrogen of the alkyl group of the (meth) acrylic acid alkyl ester is not substituted with other atoms or atomic groups.

Examples of the (meth) acrylic acid alkyl ester having an alkyl group having 1 to 8 carbon atoms include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, and n (meth) acrylate. -Butyl, isobutyl (meth) acrylate, sec-butyl (meth) acrylate, n-hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, (meth) acrylic Examples thereof include isooctyl acrylate, butyl acrylate is preferable, and n-butyl acrylate is more preferable.

In the polymer (CA), the content of the (meth) acrylic acid ester unit represented by the formula (2) is preferably 5% by mass or more, more preferably 10% by mass or more, more preferably 15% by mass or more, and 20%. By mass or more is more preferable, 25% by mass or more is more preferable, and 30% by mass or more is more preferable. In the polymer (CA), the content of the (meth) acrylic acid ester unit 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 35. More preferably, it is by mass or less. When the content of the (meth) acrylic acid ester unit represented by the 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 unit represented by the formula (2) is 50% by mass or less, the stain resistance of the curable composition after curing is improved.

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, still more preferably 15% by mass or more. 20% by mass or more is more preferable, 25% by mass or more is more preferable, and 30% by mass or more is more preferable. 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 35. More preferably, it is 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.

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

In the polymer (CA), the (meth) acrylic acid ester unit represented by the following formula (2), the monomer unit having a hydrophilic group and a polymerizable unsaturated group, and the alkyl group have 1 to 8 carbon atoms. The total content of the (meth) acrylic acid alkyl ester unit is preferably 80% by mass or more, more preferably 85% by mass or more, more preferably 90% by mass or more, still more preferably 95% by mass or more, and 100% by mass. Is more preferable.

The content of the fluoroalkyl compound (C) in the curable composition is preferably 0.2 parts by mass or more, preferably 1 part by mass or more, based on 100 parts by mass of the organic polymer (I) having a hydrolyzable silyl group. Is more preferable, 2 parts by mass or more is more preferable, and 2.5 parts by mass or more is particularly preferable. On the other hand, the content of the fluoroalkyl compound (C) in the curable composition is preferably 30 parts by mass or less, preferably 10 parts by mass or less, based on 100 parts by mass of the organic polymer (I) having a hydrolyzable silyl group. Is more preferable, and 5 parts by mass or less is particularly preferable. 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.

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 , 15 or more is preferable, 20 or more is more preferable, and 25 or more is particularly preferable. 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, the contaminants adhering to the surface of the cured product of the curable composition can be easily removed by water. When the mass ratio is 110 or less, deterioration of the cured product of the curable composition due to water can be reduced.

The mass ratio of the (meth) acrylic acid ester-based polymer (B) to the fluoroalkyl compound (C) [mass of the (meth) acrylic acid ester-based polymer (B) / mass of the fluoroalkyl compound (C)] is 1. The above is preferable, 3 or more is more preferable, and 5 or more is particularly preferable. On the other hand, the mass ratio of the (meth) acrylic acid ester-based polymer (B) to the fluoroalkyl compound (C) [mass of the (meth) acrylic acid ester-based polymer (B) / mass of the fluoroalkyl compound (C)] is , 20 or less is preferable, 15 or less is more preferable, and 10 or less is particularly preferable. 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, a good self-cleaning action by water can be imparted to the surface of the cured product of the curable composition.

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

The silanol condensation catalyst (D) is not particularly limited, and for example, dioctyl tin monodecanete, 1,1,3,3-tetrabutyl-1,3-dilauryloxycarbonyl-distanoxane, dibutyltin dilaurate, dibutyltin oxide, dibutyl. Tin diacetate, dibutyltin phthalate, bis (dibutyltin lauric acid) oxide, dibutyltin bis (acetylacetonate), dibutyltin bis (monoestermalate), tin octylate, dibutyltin octate, dioctyltin oxide, dibutyltin Organic tin compounds such as bis (triethoxysilicate), bis (dibutyltin bistriethoxysilicate) oxide, and dibutyltin oxybisethoxysilicate; organic titanium compounds such as tetra-n-butoxytitanate and tetraisopropoxytitanate. Can be mentioned. Of these, organotin compounds are preferable, and dioctyl tin oxide is more preferable. These silanol condensation catalysts may be used alone or in combination of two or more.

The content of the silanol condensation catalyst (D) in the curable composition is preferably 0.1 part by mass or more, preferably 0.2 part by mass, based on 100 parts by mass of the organic polymer (I) having a hydrolyzable silyl group. More than parts are more preferable, and 0.3 parts by mass or more are more preferable. 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, based on 100 parts by mass of the organic polymer (I) having a hydrolyzable silyl group. , 6 parts by mass or less is more preferable, and 5 parts by mass or less is more preferable. When the content of the silanol condensation catalyst (D) in the curable composition is 0.1 part by mass or more, the curing rate of the curable composition is increased and the time required for curing the curable composition is shortened. Can be planned. 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 are improved. Can be made to.

(Aminosilane compound)
The curable composition of the present invention preferably contains an aminosilane compound. The aminosilane compound may be used alone or in combination of two or more. As the aminosilane compound, aminoalkoxysilane is preferably mentioned. The aminoalkoxysilane means a compound having at least one amino group-containing functional group in one molecule and having at least two alkoxy groups directly bonded to a silicon atom. The amino group-containing functional group is preferably directly bonded to the silicon atom. The aminoalkoxysilane is preferably a compound having one amino group-containing functional group in one molecule and having three alkoxy groups directly bonded to the silicon atom. The aminosilane compound preferably does not have a fluoroalkyl group.

As the amino group-containing functional group, an aminopropyl functional group is preferable because the adhesiveness of the curable composition is improved. As aminopropyl functional groups,-(CH ₂ ) ₃ -NH ₂ ,-(CH ₂ ) ₃ -NHR ⁵ ,-(CH ₂ ) ₃ -NH (CH ₂ ) ₂ -NH ₂ (3- [N- ( 2- (2-Aminoethyl) Amino] Propyl Group) and-(CH ₂ ) ₃ -NH (CH ₂ ) ₂ -NH (CH ₂ ) ₂ -NH ₂ (3-[[2- (2-Aminoethylamino)) At least one aminopropyl functional group selected from the group consisting of ethyl] amino] propyl group) is preferred. As the aminopropyl functional group,-(CH ₂ ) ₃ -NH ₂ ,-(CH ₂ ) ₃ -NH (CH ₂ ) ₂ -NH ₂ are more preferable.

-(CH ₂ ) ₃ -In NHR ⁵ , R ⁵ has an alkyl group having 1 to 18 carbon atoms, a monovalent saturated alicyclic hydrocarbon group having 3 to 18 carbon atoms, or a carbon number of carbon atoms. 6-12 aryl groups.

Examples of the alkyl group having 1 to 18 carbon atoms in R ⁵ include a linear alkyl group and a branched chain alkyl group. Examples of the linear alkyl group include a methyl group, an ethyl group, a propyl group, an n-butyl group, an n-pentyl group, an n-hexyl group, an n-octyl group, an n-nonyl group and an n-decyl group. Examples thereof include n-undecyl group, n-dodecyl group, n-tridecyl group, n-tetradecyl group, n-pentadecyl group, n-hexadecyl group, n-heptadecyl group and n-octadecyl group. As the linear alkyl group, a methyl group, an ethyl group and an n-butyl group are preferable. Examples of the branched-chain alkyl group include an isopropyl group, an isobutyl group, a sec-butyl group, and a tert-butyl group.

Examples of the monovalent saturated alicyclic hydrocarbon group having 3 to 18 carbon atoms in R ⁵ include a cyclopentyl group, a cycloheptyl group, a cyclohexyl group, a 4-methylcyclohexyl group, a cyclooctyl group and the like. , Cyclohexyl groups are preferred.

Examples of the aryl group having 6 to 12 carbon atoms in R ⁵ include a phenyl group and the like.

Specific examples of the aminoalkoxysilane include 3-aminopropyltrimethoxysilane, 3-aminopropylmethyldimethoxysilane, 3-aminopropyltriethoxysilane, and N-2- (aminoethyl) -3-aminopropyltrimethoxy. Silane, N- (2-aminoethyl) -3-aminopropyltriethoxysilane, N, N'-bis- [3- (trimethoxysilyl) propyl] ethylenediamine, N, N'-bis- [3- (tri) Ethoxysilyl) propyl] ethylenediamine, N, N'-bis- [3- (methyldimethoxysilyl) propyl] ethylenediamine, N, N'-bis- [3- (trimethoxysilyl) propyl] hexamethylenediamine, N, N ′ -Bis- [3- (triethoxysilyl) propyl] hexamethylenediamine and the like can be mentioned, and N-2- (aminoethyl) -3-aminopropyltrimethoxysilane is preferable. Aminoalkoxysilanes may be used alone or in combination of two or more.

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

Alkoxysilane means a compound in which at least one alkyl group and at least two alkoxy groups are directly bonded to a silicon atom. As the alkylalkoxysilane, one alkyl group and three alkoxy groups are directly bonded to a silicon atom, and a monoalkyltrialkoxysilane, and two alkyl groups and two alkoxy groups are silicon. Examples thereof include dialkyldialkoxysilanes that are directly bonded to an atom. Specific examples of the monoalkyltrialkoxysilane include methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, and hexyltrimethoxysilane. Specific examples of the dialkyldialkoxysilane include dimethyldimethoxysilane, dimethyldiethoxysilane, diethyldimethoxysilane, and diethyldiethoxysilane. Of these, monoalkyltrialkoxysilane is preferable, and ethyltriethoxysilane is more preferable. The alkylalkoxysilane may be used alone or in combination of two or more.

The content of the aminosilane compound in the curable composition is preferably 0.1 part by mass or more, more preferably 0.5 part by mass or more, based on 100 parts by mass of the organic polymer (I) having a hydrolyzable silyl group. It is preferable, and 1 part by mass or more is particularly preferable. 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, based on 100 parts by mass of the organic polymer (I) having a hydrolyzable silyl group. 3 parts by mass or less is particularly preferable. When the content of the aminosilane compound is 0.1 part 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.

(filler)
The curable composition preferably further comprises a filler. According to the filler, it is possible to provide a curable composition capable of obtaining a cured product having excellent mechanical strength.

Examples of the filler include calcium carbonate, magnesium carbonate, calcium oxide, hydrous silicic acid, anhydrous silicic acid, fine powder silica, calcium silicate, titanium dioxide, clay, talc, carbon black, glass balloon and the like. Calcium carbonate is preferable, colloidal calcium carbonate and heavy calcium carbonate are preferable. These fillers may be used alone or in combination of two or more.

The average particle size of calcium carbonate is preferably 0.01 to 5 μm, more preferably 0.05 to 2.5 μm. According to calcium carbonate having such an average particle size, a cured product having excellent mechanical strength and extensibility can be obtained, and a curable composition having excellent adhesiveness can be obtained. Can be provided.

Further, calcium carbonate is preferably surface-treated with a fatty acid, a fatty acid ester, or the like. According to the calcium carbonate surface-treated with a fatty acid or a fatty acid ester, thixotropy can be imparted to the curable composition and the aggregation of calcium carbonate can be suppressed.

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 50 parts by mass with respect to 100 parts by mass of the organic polymer (I) having a hydrolyzable silyl group. More than a portion is particularly preferable. 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, based on 100 parts by mass of the organic polymer (I) having a hydrolyzable silyl group. 200 parts by mass or less is particularly preferable. 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. Further, 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.

(Plasticizer)
The curable composition may contain a plasticizer. As the plasticizer, in the case of other than polymers and oligomers, compounds having a molecular weight of 300 to 10,000 are used. In the case of polymers and oligomers, polymers having a weight average molecular weight of 400 to 11000 are preferably used as the plasticizer. Specific examples thereof include phthalates such as dioctylphthalate, dibutylphthalate and butylbenzylphthalate, polyalkylene oxides such as polypropylene glycol, and acrylic polymers, and acrylic polymers are preferable. The acrylic polymer preferably does not contain a hydrolyzable silyl group. Further, it is preferable that the acrylic polymer does not contain a (meth) acrylic acid ester unit containing a polyoxyethylene chain. Further, the acrylic polymer preferably does not have a fluoroalkyl group. In order to prevent a decrease in rubber elasticity over time, the acrylic polymer may contain hydrolyzable silyl groups, and on average, the hydrolyzable silyl groups are 0.1 to 0.5 in one molecule. It is preferable to include the individual. 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 10,000 or less, more preferably 5000 or less. When the weight average molecular weight of the acrylic polymer is 500 or more, bleed-out of the acrylic polymer can be suppressed. Further, when the weight average molecular weight of the acrylic polymer is 10,000 or less, the curable composition is sufficiently plasticized, and the cured product of the curable composition has excellent rubber elasticity.

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

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, based on 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, based on 100 parts by mass of the organic polymer (I) having a hydrolyzable silyl group.

[Dehydrating agent]
The curable composition preferably further contains a dehydrating agent. According to the dehydrating agent, when the curable composition is stored, it is possible to prevent the curable composition from being cured by the moisture contained in the air or the like.

Dehydrating agents include silane compounds such as vinyltrimethoxysilane, dimethyldimethoxysilane, tetraethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, tetramethoxysilane, phenyltrimethoxysilane, and diphenyldimethoxysilane; and methyl orthostate. , Ethyl compounds such as ethyl orthoate, methyl orthoacetate, and ethyl orthoacetate. These dehydrating agents may be used alone or in combination of two or more. Of these, vinyltrimethoxysilane is preferable.

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, based on 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, based on 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 effect obtained by the dehydrating agent can be sufficiently obtained. Further, when the content of the dehydrating agent in the curable composition is 20 parts by mass or less, the curable composition has excellent curability.

(Light stabilizer)
The curable composition may further contain a light stabilizer. Examples of the light stabilizer include hindered amine-based light stabilizers. According to the hindered amine-based light stabilizer, it is possible to provide a curable composition capable of maintaining excellent rubber elasticity for a longer period of time after curing.

Examples of the hindered amine-based light stabilizer 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) -A polycondensate of piperidyl-1,6-hexamethylenediamine and N- (2,2,6,6-tetramethyl-4-piperidyl) butylamine, 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}], polycondensate of dimethyl succinate and 4-hydroxy-2,2,6,6-piperidinethanol, etc. Hinderdamine-based light stabilizers. May be used alone or in combination of two or more.

The content of the hindered amine-based light stabilizer in the curable composition is preferably 0.01 part by mass or more, preferably 0.1 part by mass, based on 100 parts by mass of the organic polymer (I) having a hydrolyzable silyl group. The above is more preferable. On the other hand, the content of the hindered amine-based light stabilizer in the curable composition is preferably 20 parts by mass or less, preferably 10 parts by mass or less, based on 100 parts by mass of the organic polymer (I) having a hydrolyzable silyl group. More preferred.

(Other additives)
The curable composition may contain other additives such as thixotropic agents, antioxidants, UV absorbers, pigments, dyes, antioxidants, and solvents. Among them, thixotropic agents, ultraviolet absorbers, and antioxidants are preferably mentioned.

The thixotropy-imparting agent may be any as long as it can exhibit thixotropy in the curable composition. Preferred examples of the thixotropic agent include hydrogenated castor oil, fatty acid bisamide, and fumed silica.

The content of the thixotropic agent in the curable composition is preferably 0.1 part by mass or more, more preferably 1 part by mass or more, based on 100 parts by mass of the organic polymer (I) having a hydrolyzable silyl group. preferable. The content of the thixotropic agent in the curable composition is preferably 200 parts by mass or less, more preferably 150 parts by mass or less, based on 100 parts by mass of the organic polymer (I) having a hydrolyzable silyl group. When the content of the thixotropic agent in the curable composition is 0.1 part by mass or more, thixotropic property can be effectively imparted to the curable composition. Further, when the content of the thixotropic agent in the curable composition is 200 parts by mass or less, the curable composition has an appropriate viscosity and the handleability of the curable composition is improved.

Examples of the ultraviolet absorber include a benzotriazole-based ultraviolet absorber, a benzophenone-based ultraviolet absorber, and the like, and a benzotriazole-based ultraviolet absorber is preferable. The content of the ultraviolet absorber in the curable composition is preferably 0.1 part by mass or more, preferably 0.5 part by mass or more, based on 100 parts by mass of the organic polymer (I) having a hydrolyzable silyl group. More preferred. 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, based on 100 parts by mass of the organic polymer (I) having a hydrolyzable silyl group.

Examples of the antioxidant include hindered phenolic antioxidants, monophenolic antioxidants, bisphenolic antioxidants, polyphenolic antioxidants and the like. The content of the antioxidant in the curable composition is preferably 0.1 part by mass or more, preferably 0.3 part by mass or more, based on 100 parts by mass of the organic polymer (I) having a hydrolyzable silyl group. More preferred. 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, based on 100 parts by mass of the organic polymer (I) having a hydrolyzable silyl group.

Since the curable composition of the present invention can form a cured product capable of maintaining excellent rubber elasticity for a long period of time, it is used in various applications such as sealing materials, coating materials, adhesives, and paints. can do. Among them, it is preferably used as a sealing material, and more preferably used as a sealing material for joint structure.

Further, since the cured product of the curable composition of the present invention has excellent stain resistance, it reduces the adhesion of contaminants and the occurrence of rain streak stains, and even when used outdoors, for a long period of time. It is possible to maintain a beautiful appearance over the years.

As a method of applying the curable composition to the joint portion to obtain a joint structure, a method of filling the joint portion with the curable composition and then curing and curing the curable composition is used. The obtained joint structure has a wall member constituting the wall portion of the building structure and a cured product of the curable composition filled in the joint portion formed between the wall members adjacent to each other. There is. Examples of the wall portion of the building structure include an outer wall, an inner wall, a ceiling portion, and the like, and the outer wall is particularly preferable. Examples of the wall member include an outer wall member, an inner wall member, a ceiling member, and the like, and an outer wall member is preferable.

The joint portion is not particularly limited, and examples thereof include joint portions on the outer wall, inner wall, and ceiling of the building structure. The curable composition of the present invention can exhibit excellent stain resistance after curing. Further, since the curable composition of the present invention can maintain excellent rubber elasticity for a long period of time after curing, it may be caused by expansion or contraction of a member due to temperature changes such as air temperature or sunshine, or vibration or wind pressure. It exhibits excellent followability to changes in the width of joints due to the action of, and can prevent damage to members and water leakage into building structures. Therefore, the curable composition of the present invention is suitable for sealing joints such as joints on the outer wall of a building structure, which are prone to adherence of contaminants called "working joints" and stains on rain streaks. Used.

Examples of joints on the outer wall of a building structure include joints formed between outer wall members such as mortar plates, concrete plates, ceramic siding boards, metal siding boards, ALC plates, and metal plates. ..

Since the curable composition of the present invention has the above-mentioned structure, it can exhibit excellent stain resistance and maintain excellent rubber elasticity for a long period of time after curing.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited thereto.

[Synthesis of (meth) acrylic acid ester-based polymers (B1) to (B3)]
To the flask, 30 parts by mass of isobutanol was added, heated to 105 ° C., subjected to nitrogen substitution, and then while stirring under a nitrogen atmosphere, the predetermined amounts of methoxypolyethylene glycol methacrylate shown in Table 1 (the above formula). (1) (Meta) acrylic acid ester represented by (in formula (1), R ² is a methyl group, m is 9, and R ³ is a methyl group), molecular weight: 468, Shin-Nakamura Chemical Industry. Product name "NK Ester M-90G" manufactured by Co., Ltd.), butyl acrylate, 3- (trimethoxysilyl) propyl methacrylate, polymerization initiator (2,2'-azobis (2-methylbutyronitrile), Fujifilm) A solution containing Wako Junyaku Co., Ltd. (trade name “V-59”) and isobutanol was added dropwise over 5 hours, and then polymerization was carried out for 1 hour. By removing isobutanol under heating and reduced pressure from the isobutanol solution of the (meth) acrylic acid ester-based polymer thus obtained, the (meth) acrylic acid ester having the weight average molecular weight (Mw) shown in Table 1 is obtained. The system polymers (B1) to (B3) were obtained, respectively.

[Synthesis of Fluoroalkyl Compound (C3) [Polymer (CA)]]
200 parts by mass of butyl acrylate, 200 parts by mass of C ₆ FMA (C ₆ F ₁₃ CH ₂ CH ₂ OC (O) C (CH ₃ ) = CH ₂ ), and methoxypolyethylene glycol acrylate (trade name "manufactured by Nippon Oil & Fats Co., Ltd." AME400 ”, CH ₂ = CH-C (= O) -O- (CH ₂ CH ₂ O) ₁₀ -OCH ₃ , in equation (3), Q ¹ is CH ₂ = CH-C (= O) O- , R ⁸ is a methyl group, Z ² is a single bond, and q is 10) In a monomer mixture containing 200 parts by mass, 7.5 parts by mass of n-dodecyl mercaptan and 2,2'-azobis-2-methyl. 10 parts by mass of butylnitrile was added.

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) used as the fluoroalkyl compound (C). Obtained.

The following compounds were used in Examples and Comparative Examples.
[Polyalkylene oxide (A)]
Polyalkylene oxide (A1) containing a methyldimethoxysilyl group and having a main chain skeleton made of polypropylene oxide (Product name "Exester S4530" manufactured by AGC Inc., number average molecular weight (Mn): 25000, molecular weight distribution (Mw /) Mn): 1.16)
Polyalkylene oxide (A2) containing a methyldimethoxysilyl group and having a main chain skeleton made of polypropylene oxide (Product name "Exester S6735D, number average molecular weight (Mn): 30,000, molecular weight distribution (Mw / Mn) manufactured by AGC Inc." ): 1.15)
Polyalkylene oxide (A3) containing no hydrolyzable silyl group and fluoroalkyl group (Product name "Exester S2420" manufactured by AGC Inc., number average molecular weight (Mn): 17000, molecular weight distribution (Mw / Mn): 1 .4)
In addition, each of 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.

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

[Silanol condensation catalyst (D)]
Silanol Condensation Catalyst (D) (Dioctyl Tin Oxide)

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

〔filler〕
Colloidal calcium carbonate (Product name "PLS-505" manufactured by Konoshima Chemical Co., Ltd., average particle size: 0.1 μm)
Heavy calcium carbonate (Product name "Whiten SB" manufactured by Shiraishi Calcium Co., Ltd., average particle size: 2.0 μm)

[Plasticizer]
Plasticizer (Acrylic polymer not containing hydrolyzable silyl group and fluoroalkyl group, weight average molecular weight: 2000, manufactured by Toa Synthetic Co., Ltd. Product name "Alfon UP1110")
[Dehydrating agent]
Dehydrating agent (vinyl trimetothisilane, manufactured by Shin-Etsu Chemical Co., Ltd., product name "KBM-1003")
〔Antioxidant〕
Hindered phenolic antioxidant (BASF Japan product name "Irganox 1010")
[UV absorber]
Benzotriazole-based UV absorber (BASF Japan, product name "Tinubin 326")

(Examples 1 to 9 and Comparative Examples 1 to 4)
The above-mentioned polyalkylene oxides (A1) to (A3), (meth) acrylic acid ester-based polymers (B1) to (B3), fluoroalkyl compounds (C1) to (C3), silanol condensation catalyst (D), aminosilane. A stirrer in which a compound, colloidal calcium carbonate, heavy calcium carbonate, a plasticizer, a dehydrating agent, a hindered phenol-based antioxidant, and a benzotriazole-based ultraviolet absorber are each sealed in the amounts shown in Table 2. A curable composition was obtained by mixing under reduced pressure in the medium until uniform.

[Elongation rate under maximum load (initial)]
Using the curable composition, an H-type test piece was prepared according to JIS A1439 5.17 (2010). Specifically, two alumite-treated aluminum plates (length 50 mm x width 50 mm, thickness 5 mm) are used, and by sandwiching a spacer between these plates, a rectangular parallelepiped space (length 12 mm x width 50 mm x) is placed in the center between the plates. Height 12 mm) was formed. This space was filled with a curable composition to prevent air from entering. After filling the curable composition, the curable composition was allowed to stand for 14 days in an atmosphere having a temperature of 23 ° C. and a relative humidity of 50%. After that, the curable composition was further left in an atmosphere at a temperature of 30 ° C. for 14 days. By curing and curing the curable composition, an H-type test piece was prepared in which two alumite-treated aluminum plates were adhered and integrated by the cured product of the curable composition.

Then, the prepared H-type test piece was subjected to a tensile test at a tensile speed of 50 mm / min in an atmosphere of 23 ° C. and a relative humidity of 50% in accordance with JIS A1439 5.20.4 (2010), and the maximum was achieved. The elongation rate [%] under load was measured. Further, after the tensile test was completed, the fractured form of the cured product of the curable composition was visually confirmed and evaluated according to the following criteria. The results obtained are listed in the "Initial" column of Table 2.

[Elongation rate under maximum load (water at 23 ° C for 1 month)]
An H-type test piece was prepared in the same manner as above. The prepared H-type test piece was left in a state of being completely submerged in water at 23 ° C. for 1 month, and then the H-type test piece was taken out from the water and placed in an atmosphere of 23 ° C. and a relative humidity of 50% for another 24 hours. I left it. After that, a tensile test at a tensile speed of 50 mm / min was performed in an atmosphere of 23 ° C. and a relative humidity of 50% in accordance with JIS A1439 5.20.4 (2010) to obtain a maximum elongation rate [%] under load. It was measured. Further, after the tensile test was completed, the fractured form of the cured product of the curable composition was visually confirmed and evaluated according to the following criteria. The obtained results are described in the column of "23 ° C. water for 1 month" in Table 2, respectively.

[Elongation under maximum load (water at 50 ° C for 1 month)]
An H-type test piece was prepared in the same manner as above. The prepared H-type test piece was left in a state of being completely submerged in water at 50 ° C. for 1 month, and then the H-type test piece was taken out from the water and placed in an atmosphere of 23 ° C. and 50% relative humidity for another 24 hours. I left it. After that, a tensile test at a tensile speed of 50 mm / min was performed in an atmosphere of 23 ° C. and a relative humidity of 50% in accordance with JIS A1439 5.20.4 (2010) to obtain a maximum elongation rate [%] under load. It was measured. Further, after the tensile test was completed, the fractured form of the cured product of the curable composition was visually confirmed and evaluated according to the following criteria. The obtained results are described in the column of "50 ° C. water for 1 month" in Table 2, respectively. Regarding the H-type test piece produced using the curable compositions of Comparative Examples 2 to 4, the H-type test piece was left in water at 50 ° C. for 1 month and then taken out from the water. At that time, the cured product of the curable composition and the alumite-treated aluminum plate were peeled off, so that the elongation rate under maximum load could not be measured.

The criteria for evaluating the fractured form of the cured product of the curable composition is that after the tensile test is completed, the cured product of the curable composition is coagulated and fractured as "CF", and the cured product of the curable composition is interfacially fractured. Was set to "AF".

The cohesive failure of the cured product means a state in which the cured product itself is destroyed in the tensile test. Further, the interfacial fracture of the cured product means a state of peeling at the interface between the alumite-treated aluminum plate and the cured product in the tensile test. The higher the adhesive strength of the cured product of the curable composition, the more cohesive fracture occurs, and the lower the adhesive strength of the cured product of the curable composition, the more interfacial fracture occurs.

[Stain resistance (after long-term exposure test)]
A curable composition was applied to a release-treated polyethylene terephthalate (PET) substrate in an atmosphere of 23 ° C. to a thickness of 2 mm and cured for 4 weeks, whereby the curable composition was formed. A sheet-shaped test piece made of a cured product was prepared on the PET substrate. Next, after peeling the PET base material from the sheet-shaped test piece, only the sheet-shaped test piece was attached to an aluminum plate to obtain a laminated body. Then, the laminated body was exposed to the outdoors (Koka City, Shiga Prefecture) for two years with the surface of the sheet-shaped test piece perpendicular to the horizontal direction. The surface condition of the sheet-shaped specimen 3 months, 1 year, or 2 years after the exposure was visually observed and evaluated according to the following criteria. The results are shown in the columns of "3 months later", "1 year later", and "2 years later" of "contamination resistance" in Table 2, respectively.
◯: There was no adhesion of pollutants such as dust and sand and no occurrence of rain streak stains.
Δ: There was a slight adhesion of pollutants such as dust and sand and the occurrence of rain streaks, but
There is no problem in actual use.
×: There is adhesion of pollutants such as dust and sand, and rain streak stains.
It was in a very dirty state.

The curable composition of the present invention exhibits excellent stain resistance after curing and can maintain excellent rubber elasticity for a long period of time. Therefore, for example, it constitutes an outer wall of a building structure. It can be suitably used as a filler for a joint formed between existing outer wall members.

Claims (6)

An organic polymer (I) having a hydrolyzable silyl group, a (meth) acrylic acid ester-based polymer (B) containing a (meth) acrylic acid ester unit containing a polyoxyethylene chain, a fluoroalkyl compound (C), And a curable composition comprising silanol condensation catalyst (D). 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. 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. .. The content of the (meth) acrylic acid ester unit containing a polyoxyethylene chain in the (meth) acrylic acid ester-based polymer (B) is 10% by mass or more and less than 50% by mass. The curable composition according to any one of claims 1 to 3. The mass ratio of the organic polymer (I) having a hydrolyzable silyl group to the fluoroalkyl compound (C) [mass ratio of the organic polymer (I) having a hydrolyzable silyl group / mass of the fluoroalkyl compound (C)] The curable composition according to any one of claims 1 to 4, wherein the composition is 25 or more and 50 or less. The fluoroalkyl compound (C) has 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 an alkyl group having 1 to 1 to carbon atoms. The curable composition according to any one of claims 1 to 5, which comprises 8 (meth) acrylic acid alkyl ester units. However, in the 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. Is.