JP2004307836A - Curable composition, sealing medium, adhesive and joint structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a curable composition which cures with moisture in the atmosphere and gives a rubbery cured product excellent in elongation properties, a sealing medium and an adhesive which use the curable composition, and a joint structure obtained by using the curable composition. <P>SOLUTION: The curable composition comprises an organic polymer (a) containing at least a crosslinkable hydrolyzable silyl group and an organic polymer (b) having substantially the same main chain structure as the organic polymer (a) and at least a polar group. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a curable composition which is crosslinked by atmospheric moisture to give a cured product having elasticity and excellent durability, for example, a sealing material, an adhesive, a paint, a coating material, a sealant, a primer, and the like. It relates to a suitable curable composition.

  Conventionally, various curable compositions containing a (meth) acrylic polymer having an alkoxysilyl group as a main component have been proposed. (For example, Patent Documents 1 to 3 below). These curable compositions are crosslinked by the moisture of the atmosphere to give a cured product having excellent durability, weather resistance, transparency and adhesiveness. Therefore, the curable composition is used for various applications such as paints, coatings, adhesives, pressure-sensitive adhesives, sealants and sealing materials.

When the curable composition is used for a sealing material or the like, the cured product may be required to be rubbery and have sufficient elongation.
However, although the cured product of the vinyl polymer having an alkoxysilyl group is rubbery, there is a limit to the elongation of the cured product, and it has been difficult to develop more sufficient elongation. For example, a curable composition for a paint excellent in weather resistance and adhesive strength to a metal is disclosed (see Patent Document 4), but elongation is not always sufficient.

  Conventionally, in order to achieve excellent elongation properties, a method of adding an organic silicone compound (see Patent Document 5) and a method of adding a compound having one silanol group in the molecule (see Patent Document 6) have been proposed. Proposed. However, depending on the polymer having an alkoxysilyl group, satisfactory elongation characteristics of a cured product cannot be obtained by these methods, or it is difficult to measure a balance with other physical properties.

JP-A-57-179210 JP-A-4-202585 JP-A-11-43512 JP-A-4-258657 JP-A-64-9268 JP-A-8-157734

As described above, there has been a strong demand for a conventional curable composition using a vinyl polymer having an alkoxysilyl group, in which the cured product develops more elongation.
An object of the present invention is to provide a curable composition which is cured by moisture in an atmosphere to give a rubber-like cured product, and further has an excellent elongation property of the cured product, in view of the above-mentioned state of the art, and the curable composition. An object of the present invention is to provide a sealing material and an adhesive using an object.

  The curable composition according to the present invention has an organic polymer (a) containing at least a crosslinkable hydrolyzable silyl group, a substantially same main chain structure as the organic polymer (a), and at least a polar polymer. A curable composition comprising an organic polymer (b) having a group.

  In the present invention, an organic polymer (b) having substantially the same main chain structure as the organic polymer (a) and having at least a carboxyl group is preferably used as the organic polymer (b).

  In a specific aspect of the curable composition according to the present invention, the main chain structure of the organic polymer (a) is a polyether, polyester, polycarbonate, polyurethane, polyamide, polyurea, polyimide, polysiloxane, halogenated polymer, It is one selected from the group consisting of a vinyl polymer obtained by polymerizing the unsaturated group and a main chain structure obtained by combining these structures.

  In the present invention, a vinyl polymer (a1) containing at least a crosslinkable hydrolyzable silyl group is preferably used as the organic polymer (a).

  In the present invention, the vinyl polymer (a1) having at least a crosslinkable hydrolyzable silyl group is preferably a polymer synthesized by radical polymerization using a peroxide as a polymerization initiator. is there.

  In the present invention, a (meth) acrylate polymer is preferably used as the vinyl polymer (a1) containing at least a crosslinkable hydrolyzable silyl group.

  In the present invention, preferably, the (meth) acrylate polymer is a polymer synthesized by irradiating ultraviolet (UV) light.

  In the curable composition according to the present invention, when the organic polymer (a) is a vinyl polymer (a1), a polyether polymer (c) having at least a crosslinkable hydrolyzable silyl group is further included. It may be blended.

  In the curable composition according to the present invention, preferably, at least one of the organic polymer (a) and the organic polymer (b) has a viscosity at 25 ° C of 0.01 to 500 Pa.s. s.

  The curable composition according to the present invention preferably further contains a layered silicate.

  In the curable composition according to the present invention, the cured product is preferably rubbery at 0 to 40 ° C.

  The sealant and the adhesive of the present invention each comprise the curable composition according to the present invention.

The joint structure of the present invention uses the sealing material according to the present invention, and the cured product has a dumbbell-shaped breaking elongation of 1000% or more.
Hereinafter, details of the present invention will be described.

(Organic polymer (a))
The organic polymer (a) used in the present invention is not particularly limited as long as it has a crosslinkable hydrolyzable silyl group. When the hydrolyzable silyl group is hydrolyzed to form a siloxane bond, the organic polymer is crosslinked to form a rubber-like cured product.

  The hydrolyzable silyl group is a group in which one to three hydrolyzable groups are bonded to a silicon atom. Examples of the hydrolyzable group include hydrogen, a halogen atom, a methoxy group, and an ethoxy group. Preferable examples include an alkoxy group, an acyl oxide group, a ketoximate group, an amino group, an amide group, an acid amide group, an aminooxy group, a mercapto group, and an alkenyl oxide group, and do not generate harmful by-products during the reaction. Alkoxy groups are particularly preferred.

Examples of the alkoxy group include a methoxy group, an ethoxy group, a propyloxy group, an isopropyloxy group, a butoxy group, a tert-butoxy group, a phenoxy group, a benzyloxy group, and the like.These alkoxy groups are of the same type. They may be present or different types may be combined.
Examples of the alkoxysilyl group having an alkoxy group bonded to a silicon atom include trialkoxysilyl groups such as trimethoxysilyl group, triethoxysilyl group, triisopropoxysilyl group and triphenoxysilyl group; dimethoxymethylsilyl group, diethoxy Dimethoxysilyl group such as methylsilyl group; monoalkoxysilyl group such as methoxydimethoxysilyl group and ethoxydimethylsilyl group. These may be used in combination, or different alkoxy groups may be used in combination.

  The main chain structure of the organic polymer (a) having at least one crosslinkable hydrolyzable silyl group capable of being crosslinked by forming the siloxane bond, that is, the crosslinkable hydrolyzable silyl group is not particularly limited, and the polyether main chain structure , Polyester backbone structure, polycarbonate backbone structure, polyurethane backbone structure, polyamide backbone structure, polyurea backbone structure, polyimide backbone structure, polysiloxane backbone structure, vinyl polymer obtained by polymerizing polymerizable unsaturated groups. And a main chain structure obtained by combining these structures. The organic polymer (a) preferably comprises a vinyl polymer and / or a polyether polymer. That is, the main chain may be a vinyl polymer, a polyether polymer, or have both a polyether polymer portion and a vinyl polymer portion.

  Examples of the polyether main chain structure include a main chain structure such as polyethylene glycol, polypropylene glycol, polytrimethylene glycol, and polytetramethylene glycol, a copolymer structure thereof, and a derivative having a substituent. As a commercially available polymer having a polyether main chain structure having a hydrolyzable silyl group, a silyl polymer such as MS Polymer S-203, S-303, S-903, etc. as a trade name MS Polymer from Kanegabuchi Chemical Industry Co., Ltd. Examples thereof include Cyril SAT-200, MA-403, and MA-447, and Exester ESS-2410, ESS-2420, and ESS-3630 from Asahi Glass Co., Ltd.

As the polyester main chain structure, glycols such as ethylene glycol, propylene glycol, neopentyl glycol, and tetramethylene glycol are condensed with dicarboxylic acids such as terephthalic acid, isophthalic acid, sebacic acid, succinic acid, phthalic acid, and adipic acid. And the resulting polyester main chain structure.
Examples of the polyurethane main chain structure include a polyurethane main chain structure obtained by polyaddition of a polyether polyol, a polyol such as a polyester polyol, and an isocyanate such as xylylene diisocyanate, isophorone diisocyanate, methylene diphenyl diisocyanate, and toluylene diisocyanate. .
Examples of the polyamide main chain structure include a polyamide main chain structure obtained by condensation of a diamine and a dicarboxylic acid or ring-opening polymerization of caprolactam.
Examples of the polyurea main chain structure include a polyurea main chain structure obtained by polyaddition of a diamine and a diisocyanate.
Examples of the polyimide main chain structure include a polyimide main chain structure obtained by imidizing a diamine and a compound having two cyclic acid anhydride structures in one molecule.
The polysiloxane main chain structure includes polysiloxane main chain structures such as polydimethylsiloxane, polydiethylsiloxane, polydiphenylsiloxane, and polymethylphenylsiloxane.

  The vinyl polymer structure obtained by polymerizing the polymerizable unsaturated group is not particularly limited as long as it is a vinyl polymer structure obtained by polymerizing a compound having a polymerizable unsaturated group. The vinyl polymer obtained by polymerizing the compound having a polymerizable unsaturated group may be a polymer obtained by polymerizing a vinyl monomer, such as polyethylene, polypropylene, polyisobutylene, and poly (meth) acrylate. , Polystyrene, polyvinyl chloride, polyvinylidene chloride, polybutadiene, polyisoprene, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, and polyvinyl ether. Further, a copolymer having these vinyl polymer portions may be used. Among the above-mentioned vinyl polymers, (meth) acrylate polymers having a number average molecular weight of 8000 or more and copolymers with other vinyl monomers are preferably used from the viewpoint of cohesive strength and adhesiveness. Here, (meth) acryl is an expression collectively showing methacryl and acryl.

As the (meth) acrylate, for example, 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, isomyristyl (meth) acrylate, stearyl (meth) acrylate, isobornyl (meth) acrylate, benzyl (meth) A) acrylate, 2-butoxyethyl (meth) acrylate, 2-phenoxyethyl (meth) acrylate, glycidyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, Sundiol di (meth) acrylate, ethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, polypropylene 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 acrylate, polyester acrylate, urethane acrylate, 2- Hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydro Cypropyl (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, pentaerythritol tri (meth) acrylate, 2-[(meth) acryloyloxy] ethyl 2-hydroxyethylphthalic acid, 2-[(meth) acryloyloxy ] Ethyl 2-hydroxypropyl phthalic acid,
[Compound 1]
CH2 = CH-C (O) O-CH2CH2O-
[C (O) CH2CH2CH2CH2CH2O] n-H
(N = 1 to 10)
[Compound 2]
CH2 = C (CH3) -C (O) O-CH2CH2O-
[C (O) CH2CH2CH2CH2CH2O] n-H
(N = 1 to 10)
[Compound 3]
CH2 = CH-C (O) O- (CH2CH2O) n-H
(N = 1 to 12)
[Compound 4]
CH2 = C (CH3) -C (O) O- (CH2CH2O) n-H
(N = 1 to 12)
[Compound 5]
CH2 = CH-C (O) O- [CH2CH (CH3) O] n-H
(N = 1 to 12)
[Compound 6]
CH2 = C (CH3) -C (O) O- [CH2CH (CH3) O] n-H
(N = 1 to 12)
[Compound 7]
CH2 = C (CH3) -C (O) O- (CH2CH2O) n-
[CH2CH (CH3) O] m-H
(N = 1 to 12)
(M = 1-12)
[Compound 8]
CH2 = CH-C (O) O- (CH2CH2O) n-
[CH2CH (CH3) O] m-H
(N = 1 to 12)
(M = 1-12)
[Compound 9]
CH2 = C (CH3) -C (O) O- (CH2CH2O) n-
(CH2CH2CH2CH2O) mH
(N = 1 to 12)
(M = 1-12)
[Compound 10]
CH2 = CH-C (O) O- (CH2CH2O) n-
(CH2CH2CH2CH2O) mH
(N = 1 to 12)
(M = 1-12)
[Compound 11]
CH2 = CH-C (O) O- (CH2CH2O) n-CH3
(N = 1 to 10)
[Compound 12]
CH2 = C (CH3) -C (O) O- (CH2CH2O) n-CH3
(N = 1-30)
[Compound 13]
CH2 = CH-C (O) O- [CH2CH (CH3) O] n-CH3
(N = 1 to 10)
[Compound 14]
CH2 = C (CH3) -C (O) O- [CH2CH (CH3) O] n-CH3 (n = 1 to 10)
[Compound 15]
CH2 = C (CH3) -C (O) O- (CH2CH2O) n-
[CH2CH (CH3) O] m-H
(N = 1 to 10)
(M = 1-10)
[Compound 16]
CH2 = CH-C (O) O- (CH2CH2O) n-
[CH2CH (CH3) O] m-H
(N = 1 to 10)
(M = 1-10)
[Compound 17]
CH2 = CH-C (O) O- [CH2CH (CH3) O] n
-C (O) -CH = CH2
(N = 1-20)
[Compound 18]
CH2 = C (CH3) -C (O) O- [CH2CH (CH3) O] n
-C (O) -C (CH3) = CH2
(N = 1-20)
[Compound 19]
CH2 = CH-C (O) O- (CH2CH2O) n-C (O) -CH = CH2
(N = 1-20)
[Compound 20]
CH2 = C (CH3) -C (O) O- (CH2CH2O) n
-C (O) -C (CH3) = CH2
(N = 1 to 20).

  Examples of the other vinyl monomers include, for example, styrene, indene, α-methylstyrene, p-methylstyrene, p-chlorostyrene, p-chloromethylstyrene, p-methoxystyrene, p-tert-butoxystyrene, divinylbenzene, and the like. Styrene derivatives; compounds having vinyl ester groups such as vinyl acetate, vinyl propionate, vinyl butyrate, vinyl caproate, vinyl benzoate, vinyl cinnamate; maleic anhydride, N-vinylpyrrolidone, N-vinyl morpholine , (Meth) acrylonitrile, (meth) acrylamide, N-cyclohexylmaleimide, N-phenylmaleimide, N-laurylmaleimide, N-benzylmaleimide, n-propylvinylether, n-butylvinylether, isobutylvinylether, ter -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, triethylene 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, glue Di (4-vinyloxy) butyl talate, di (4-vinyloxy) butyl succinate trimethylolpropane trivinyl ether, 2-hydroxyethyl vinyl ether, 4-hydroxybutyl vinyl ether, 6-hydroxyhexyl vinyl ether, cyclohexane-1,4-di Examples thereof include compounds having a vinyloxy group such as methanol-monovinyl ether, diethylene glycol monovinyl ether 3-aminopropyl vinyl ether, 2- (N, N-diethylamino) ethyl vinyl ether, urethane vinyl ether, and polyester vinyl ether.

  The vinyl polymer (a1) may contain a halogen element. For example, polyvinyl chloride, polyvinylidene chloride, polytetrafluoroethylene, chlorinated polyethylene, chlorinated polypropylene, poly (meth) acrylic acid Perfluoroalkyl and the like.

  As a method for producing the vinyl polymer (a1), a known method can be used. For example, 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, a living radical polymerization method, or the like can be used, and depending on the polymerization reaction of the monomer. A polymerization method may be appropriately selected.

Methods for introducing a crosslinkable hydrolyzable silyl group into a vinyl polymer include methacrylic acid esters having a crosslinkable silyl group, copolymerizable monomers having a crosslinkable hydrolyzable silyl group, and crosslinkable A method of introducing a polymer at the time of polymerizing using an initiator having a novel hydrolyzable silyl group, a chain transfer agent having a crosslinkable hydrolyzable silyl group, or the like (for example, JP-A-54-123192, JP-A-57-179210, JP-A-59-78220, JP-A-60-23405), a method of synthesizing a polymer having an alkenyl group, and then introducing an alkoxysilyl group by hydrosilylation (for example, JP-A-54-40893 and JP-A-11-80571).
The method for producing the vinyl polymer having a crosslinkable silyl group (a1) constituting the present invention is not particularly limited as long as the vinyl polymer having a crosslinkable silyl group (a1) is obtained. A known manufacturing technique such as described above can be used.

  As a method for producing the vinyl polymer (a1), a free radical polymerization method using a peroxide initiator and an azo compound initiator as a polymerization initiator is preferable. In particular, a free and shining polymerization method using a peroxide-based polymerization initiator is preferable because the coalescence easily changes.

  Examples of the peroxide-based polymerization initiator include benzoyl peroxide, isobutyryl peroxide, isononanoyl peroxide, decanoyl peroxide, lauroyl peroxide, parachlorobenzoyl peroxide, di (3,5,5-trimethyl peroxide). Diacyl peroxides such as hexanoyl) peroxide; diisopropyl purge carbonate, di-sec-butyl purge carbonate, di-2-ethylhexyl purge carbonate, di-1-methylheptyl purge carbonate, di-3-methoxybutyl purge carbonate, dicyclohexyl Peroxydicarbonates such as purge carbonate; tert-butyl perbenzoate, tert-butyl peracetate, tert-butyl per-2-ethylhexanoate Peroxy esters such as tert-butyl perisobutyrate, tert-butyl perpivalate, tert-butyl diperadipate, cumyl pernedecanoate; ketone peroxides such as methyl ethyl ketone peroxide and cyclohexanone peroxide Dialkyl peroxides such as di-tert-butyl peroxide, dicumyl peroxide, tert-butyl cumyl peroxide, 1,1-di (t-hexylperoxy) -3,3,5-trimethylcyclohexane; Hydroperoxides such as cumene hydroxyperoxide and tert-butyl hydroperoxide; and 1,1-di (t-hexylperoxy) -3,3,5-trimethylcyclohexane. . In addition, only one type of peroxide may be used, or a plurality of types may be used in combination. Further, the peroxide may be added sequentially multiple times.

  Examples of the chain transfer agent having a crosslinkable hydrolyzable silyl group include, for example, a functional group having a high chain transfer property such as mercaptomethyltrimethylsilane, 3-mercaptopropyltrimethoxysilane, and 3-mercaptopropyldimethoxysilane. Alkoxysilane is mentioned. The amount of the chain transfer agent having a crosslinkable hydrolyzable silyl group is preferably 0.01 to 20 parts by weight, more preferably 0.1 to 5 parts by weight, per 100 parts by weight of the vinyl polymerizable monomer. Parts by weight.

  Examples of the (meth) acrylate having a crosslinkable hydrolyzable silyl group include N- (3-acryloyloxy-2-hydroxypropyl) -3-aminopropyltriethoxysilane and 3-acryloyloxypropyldimethylmethoxysilane. 3-acryloyloxypropylmethyldimethoxysilane, 3-acryloyloxypropyltrimethoxysilane, 3-acryloyloxypropylmethylbis (trimethylsiloxy) silane, 3-methacryloyloxypropyldimethylmethoxysilane, 3-methacryloyloxypropyldimethylethoxysilane, 3-methacryloyloxypropylmethyldimethoxysilane, 3-methacryloyloxypropylmethyldiethoxysilane, 3-methacryloyloxypropyltrimethoxy Run, 3-methacryloyloxy-propenyl trimethoxy silane, and the like. These methacrylates may be used alone or two or more of them may be used in combination.

Examples of the copolymerizable monomer having a crosslinkable hydrolyzable silyl group include vinylmethyldiacetoxysilane, vinyltriacetoxysilane, vinyldimethylmethoxysilane, vinyldimethylethoxysilane, vinylmethyldiethoxysilane, vinyltrimethoxysilane, Vinyltriethoxysilane, vinyl triisopropoxysilane, vinyltriphenoxysilane, vinyldimethylisopentenyloxysilane, vinyldimethyl-2-((2-ethoxyethoxy) ethoxy) silane, vinyltris (1-methylvinyloxy) silane, vinyltris (2-methoxyethoxy) silane, phenylvinyldiethoxysilane, diphenylvinylethoxysilane, 6-triethoxysilyl-2-norbornene, oct-7-enyltrimethoxysilane, Styryl ethyltrimethoxysilane, allyl triethoxysilane, allyl trimethoxysilane, and the alkoxysilane having a polymerizable unsaturated group such as 3-allyl-aminopropyltrimethoxysilane. These monomers may be used alone or two or more kinds may be used in combination.
The amount of the (meth) acrylic acid ester or copolymerizable monomer having a crosslinkable hydrolyzable silyl group is preferably 0.01 to 20% by weight based on 100% by weight of the vinyl polymerizable monomer. More preferably, the content is 0.1 to 5% by weight.

(Organic polymer (b))
The organic polymer (b) is an organic polymer having at least a polar group, and is not particularly limited as long as the main chain structure is substantially the same as the organic polymer (a). Here, examples of the polar group include a carboxyl group and a phenolic hydroxyl group, and a carboxyl group is preferably used. The substitution position of the carboxyl group to the polymer may be at the terminal of the polymer or at the side chain. Further, a carboxyl group may be located at both the polymer terminal and the side chain.

  In obtaining the organic polymer (b), a commercially available polymer may be used, or the polymer having a hydroxyl group may be reacted with an acid anhydride to obtain the organic polymer (b) having a carboxyl group. For example, the organic polymer (b) may be obtained by an esterification reaction of polypropylene glycol, polyester, or polyurethane having hydroxyl groups at both ends with a cyclic acid anhydride such as maleic anhydride or succinic anhydride. Further, a polyimide in which an amino group is excessively present and imidized with an acid anhydride and then an amic acid is left may be used as the organic polymer (b).

  When the organic polymer (b) is a vinyl polymer, the organic polymer (b) may be obtained by copolymerizing a carboxyl group-containing vinyl monomer as described below. Alternatively, a carboxyl group-containing vinyl polymer may be obtained by performing polymerization in the presence of a chain transfer agent having a carboxyl group such as thioglycolic acid, and the polymerization is started using an initiator having a carboxyl group. Thereby, a carboxyl group-containing vinyl polymer may be obtained. Further, a plurality of these methods may be combined.

  Examples of the vinyl monomer having a carboxyl group include (meth) acrylic acid, acrylic acid dimer, 2-acryloyloxyethylsuccinic acid, 2-methacryloyloxyethylsuccinic acid, 2-acryloyloxyethylphthalic acid, and 2-methacryloyloxyethylphthalic acid. , 2-acryloyloxyethyl hexahydrophthalic acid, 2-methacryloyloxyethyl hexahydrophthalic acid, 2-acryloyloxyisopropyl phthalic acid, 2-methacryloyloxyisopropyl phthalic acid, and the like.

(Viscosity of organic polymers (a) and (b))
In the curable composition according to the present invention, preferably, the viscosity of at least one of the organic polymer (a) and the organic polymer (b) is in a range of 0.01 Pa · s to 500 Pa · s at 25 ° C. It is desirable. When the viscosity of each of the organic polymers (a) and (b) is less than 0.01 Pa · s at 25 ° C., the liquid composition becomes easy to handle, but it may be difficult to impart thixotropic properties due to viscosity adjustment. When the viscosity of any of the organic polymers (a) and (b) exceeds 500 Pa · s at 25 ° C., although the curable composition may exhibit cold flow properties, application and the like become difficult and handling becomes difficult. It can be. Therefore, when the curable composition according to the present invention is used as a liquid or paste adhesive or sealing material, the viscosity range is desirably within the above range. More preferably, the viscosity of at least one of the organic polymers (a) and (b) is in the range of 0.1 to 50 Pa · s at 25 ° C., more preferably 1 to 30 Pa · s.

  Moreover, the viscosity range in which the curable composition is excellent in coatability and coatability is 0.05 to 500 Pa · s, preferably 0.1 to 100 Pa · s in viscosity at 25 ° C.

(Molecular weight of organic polymers (a) and (b))
In the curable composition according to the present invention, in order to improve the elongation of the cured product and to make the curable composition a liquid or paste-like composition in which stringing is difficult to occur, the organic polymers (a) and (b) are used. It is preferable that at least one of the number average molecular weights (polystyrene equivalent molecular weight determined by gel permeation chromatography, GPC) is in the range of 5,000 to 100,000. When both of the organic polymers (a) and (b) have a number average molecular weight of less than 5,000, the liquid composition becomes easy to handle, but the elongation of the cured product may not be sufficiently obtained. When the number average molecular weight of any of the organic polymers (a) and (b) exceeds 100,000, a composition having excellent elongation properties of a cured product can be obtained, but a liquid composition in which stringing easily occurs. It may be. More preferably, the number average molecular weight of at least one of the organic polymers (a) and (b) is from 1,000 to 50,000, more preferably from 5,000 to 30,000.

(Blending ratio)
The preferable mixing ratio of the organic polymer (a) and the organic polymer (b) is 10 to 98 parts by weight of the organic polymer (a) based on 100 parts by weight of the total of the organic polymers (a) and (b). It is desirable to set the range of parts. When the blending ratio of the organic polymer (a) is less than 10 parts by weight, even if the organic polymer (a) is cured by crosslinking, it may not be possible to form a cured product as a whole. If the compounding ratio of the organic polymer (a) exceeds 98 parts by weight, the compounding ratio of the organic polymer (b) becomes extremely small, and sufficient elongation of the cured product may not be expected. More preferably, the mixing ratio of the organic polymer (a) is 30 to 95 parts by weight, and further preferably 50 to 90 parts by weight.

  (Polyether-based polymer (c) having at least a crosslinkable hydrolyzable silyl group) By adding the polyether-based polymer (c), the water resistance of the cured product was increased or a sealing material was formed. In this case, rubber elasticity can be increased.

When the vinyl polymer (a1) and the polyether polymer (c) are used in combination, the mixing ratio is 0.1 parts by weight of the polyether polymer (c) per 100 parts by weight of the vinyl polymer (a1). It is preferably from 250 to 250 parts by weight, more preferably from 0.5 to 100 parts by weight.
If the blending ratio of the polyether-based polymer (c) is less than 0.1 part by weight, the effect of improving adhesion and water resistance may be reduced, and if it exceeds 250 parts by weight, weather resistance may be significantly reduced. Because there is.

  The polyether polymer (c) having a crosslinkable hydrolyzable silyl group is a polyether polymer whose main chain is essentially a polyether polymer and which has a crosslinkable hydrolyzable silyl group at the terminal. (C) wherein the main chain is essentially a general formula [-(RO) n-, wherein R represents an alkylene group having 1 to 4 carbon atoms. And a polymer containing a chemically crosslinked hydrolyzable silyl group at a terminal.

Further, the polyether-based polymer (c) may be a copolymer having a main chain composed of a polyether and a (meth) acrylate.
The polymer (c) is synthesized, for example, by reacting a polyalkylene oxide having an allyl group at a terminal with a hydrosilane compound represented by the following chemical formula (1) in the presence of a Group VIII transition metal.

(Wherein R ¹ is a group selected from a monovalent hydrocarbon group and a halogenated monovalent hydrocarbon group, n is an integer of 0, 1 or 2, X is a halogen atom, an alkoxy group, an acyloxy group and Means an atom or group selected from ketoxime groups.)

  Examples of the polyalkylene oxide that is the main chain of the polymer (c) include polyethylene oxide, polypropylene oxide, and polybutylene oxide. The cured product of the curable composition has excellent water resistance and a sealing material. Polypropylene oxide is preferred from the viewpoint that the elasticity can be secured.

  Examples of the crosslinkable hydrolyzable silyl group include the same silyl group as the hydrolyzable silyl group contained in the polymer (a), and an alkoxysilyl group that does not generate a harmful by-product during the reaction. It is preferably used.

  The number average molecular weight of the polyether polymer (c) is preferably 4,000 to 100,000. If the number average molecular weight is less than 4,000, the cured product will not have sufficient elongation, and the followability to the ground will be reduced, and if it is more than 100,000. The viscosity before curing becomes high, and the workability in the compounding process becomes poor. More preferably, it is 10,000 to 30,000, and the molecular weight distribution (Mw / Mn) is desirably 1.6 or less.

  Examples of the polyether-based polymer (c) include "MS Polymer" (trade name) (manufactured by Kaneka Chemical Industry Co., Ltd.) and "Silyl Polymer" (trade name) such as MS Polymer S-203 and S-303. (Manufactured by Fuchi Chemical Industry Co., Ltd.), Cyril SAT-200, SAT-350, and SAT-400, and trade names "Exester" (made by Asahi Glass Co., Ltd.) as Exester ESS-3620, ESS-3430, ESS-2420, ESS -410 and the like are commercially available.

(Layered silicate)
The layered silicate preferably used in the present invention means a silicate mineral having exchangeable cations between layers. The layered silicate used in the present invention is not particularly limited, and includes, for example, montmorillonite, saponite, hectorite, beidellite, stevensite, smectite-based clay minerals such as nontronite, vermiculite, halloysite, and swellable mica. Can be Among them, montmorillonite and swellable mica are preferable. The layered silicate may be a natural product or a synthetic product, and one or more of these may be used.

  As the above-mentioned layered silicate, it is more preferable to use smectites or swellable mica having a large shape anisotropy effect defined by the following formula from the viewpoint of improving the mechanical strength of the curable composition and the gas barrier property. FIG. 1 schematically shows the crystal surface (A) and the crystal end surface (B) of the layered silicate.

  Shape anisotropy effect = Area of crystal surface (A) / Area of crystal end face (B)

  As shown in FIG. 2, the exchangeable cations existing between the layers of the layered silicate are ions such as sodium and calcium on the crystal surface, and these ions have an ion exchange property with a cationic substance. Therefore, various cationic substances can be trapped (intercalated) between the layers of the layered silicate.

  The cation exchange capacity of the layered silicate is not particularly limited, but is preferably 50 to 200 milliequivalents / 100 g. If the amount is less than 50 milliequivalents / 100 g, the amount of the cationic surfactant that can be trapped (intercalated) between the crystal layers by ion exchange decreases, and the interlayer may not be sufficiently nonpolarized. On the other hand, if it exceeds 200 milliequivalents / 100 g, the bonding strength between the layers of the layered silicate becomes strong, and it may be difficult to increase the distance between the crystal flakes constituting each layer of the layered silicate.

The layered silicate is blended in an amount of 0.1 to 100 parts by weight, more preferably 0.5 to 50 parts by weight, particularly preferably 1 to 10 parts by weight, based on 100 parts by weight of the base resin. If the amount is less than 0.1 part by weight, the effect of improving the weather resistance and flame retardancy of the cured product is hardly exhibited. If the amount exceeds 10 parts by weight, the viscosity of the curable composition becomes high and workability and productivity are reduced. There is.
The base resin refers to the organic polymer (a), (b), or the vinyl polymer (a1) and the organic polymer (b) and the polyether polymer (c) added as necessary. ).

  The layered silicate preferably has an average interlayer distance of the (001) plane measured by a wide-angle X-ray diffraction measurement method of 3 nm or more, and is preferably dispersed including five or less layers. When the average interlayer distance is 3 nm or more, and the number of layers is 5 or less, the curable composition is advantageous for exhibiting the weather resistance and the flame retardancy.

  In this specification, the average interlayer distance of the layered silicate is an average interlayer distance when a fine flaky crystal is used as a layer, and is obtained by X-ray diffraction peak and transmission electron microscopy, It can be calculated by a line diffraction measurement method. A state in which the layers are cleaved to 3 nm or more and dispersed including those existing in 5 layers or less means that a part or all of the layered silicate laminate is dispersed, This is because the interaction between the layers is weakened.

  Further, when the average interlayer distance of the layered silicate is 6 nm or more, it is particularly advantageous to exhibit functions such as flame retardancy, mechanical properties, and heat resistance. When the average interlayer distance is 6 nm or more, the crystalline flake layers of the layered silicate are separated from each other and the interaction of the layered silicate is weakened to a negligible level. The state of dispersion in the above progresses in the direction of peeling stabilization. That is, the layered silicate is stably present in the curable composition in a state where the layered silicate is separated into flakes one by one.

  As the dispersion state of the layered silicate, it is preferable that the flaky crystals of the layered silicate are highly dispersed in the base resin. More specifically, it is preferable that 10% by weight or more of the layered silicate is dispersed in a state in which 5 layers or less exist, and more preferably, 20% by weight or more of the layered silicate has 5 layers or less. Desirably it exists in a state. Furthermore, if the number of dispersed flaky crystals is 5 or less, the effect of the addition of the layered silicate can be obtained favorably, but if it is 3 or less, it is more preferable, and the dispersion is monolayer. It is even more desirable.

  The layered silicate of the present invention is preferably a layered silicate treated with a quaternary ammonium salt. This is because the dispersibility of the layered silicate in the base resin can be improved by treating with a quaternary ammonium salt. Also, quaternary ammonium salts are known to have a catalytic action on the crosslinking reaction of the polyether polymer, and are dispersed in the base resin together with the layered silicate to improve dispersibility and accelerate the curing rate. It is also possible to make it.

  Examples of the quaternary ammonium salt include lauryl trimethyl ammonium salt, stearyl trimethyl ammonium salt, trioctyl ammonium salt, distearyl dimethyl ammonium salt, di-hardened tallow dimethyl ammonium salt, distearyl dibenzyl ammonium salt, and N-polyoxyethylene. —N-lauryl-N, N-dimethylammonium salt and the like. These quaternary ammonium salts may be used alone or in combination of two or more. Among these, a quaternary alkylammonium ion salt having an alkyl chain having 6 or more carbon atoms or a polyoxyalkylene chain is preferable because good dispersibility can be obtained.

  Various stirrers can be used to disperse the layered silicate, but when dispersion is difficult, it may be easy to obtain a desired dispersion state by dispersing using a high-shearing device such as a three-roller.

(UV absorber and light stabilizer)
The curable composition of the present invention preferably contains various ultraviolet absorbers and light stabilizers in order to improve weather resistance. This is because when used in combination with the layered silicate, the layered silicate acts to suppress the bleed-out of various ultraviolet absorbers and light stabilizers, so that these are retained in the cured product for a long time.

  Examples of the above-mentioned ultraviolet absorber include known ultraviolet absorbers such as benzotriazole-based and benzophenone-based ones. Among them, benzotriazole-based ultraviolet absorbers are preferable because of their high ultraviolet absorption performance. When the above-mentioned ultraviolet absorbent is blended, it is preferable to blend 0.1 to 20 parts by weight, more preferably 0.5 to 10 parts by weight, with respect to 100 parts by weight of the base resin. If the amount is less than 0.1 part by weight, the effect of improving the weather resistance may be insufficient. If the amount is more than 20 parts by weight, a problem such as impairing the appearance as a sealing material due to coloration occurs.

  As the light stabilizer, for example, a hindered amine light stabilizer is used. The hindered amine-based light stabilizer generally exhibits excellent effects when used in combination with an ultraviolet absorber. Among the above hindered amine light stabilizers (hereinafter, light stabilizers), those having a group having a structure represented by the following general formula (A) in the molecule have a particularly remarkable effect when used in combination with a layered silicate. Examples of such hindered amine light stabilizers include, for example, bis (2,2,6,6-tetramethyl-4-piperidine) sebacate, poly [@ 6- (1,1,3,3, -tetramethylbutyl) ) Amino-1,3,5-triazine-2,4-diyl {(2,2,6,6-tetramethyl-4-piperidine) imino} hexamethylene} (2,2,6,6-tetramethyl -4-piperidine) imino}] and the like. These may be used alone or in combination of two or more.

  It is considered that the weathering effect by the combined use with the layered silicate is mainly the effect of preventing the bleed out of the light stabilizer. That is, it is considered that the layered silicate interacts with the light stabilizer in the composition to prevent the light stabilizer from dissipating from the system. In addition, it is considered that the bleed out of the light stabilizer is suppressed by the layer silicate acting as a plate that inhibits bleed out among the interactions. Among the light stabilizers, those having a group having a structure represented by the following general formula (2) in the molecule are particularly remarkable in their effect, presumably because H atoms bonded to N atoms are involved. .

  When the light stabilizer is blended, it is preferably blended in an amount of 0.1 to 20 parts by weight, more preferably 0.5 to 10 parts by weight, based on 100 parts by weight of the base resin. If the amount is less than 0.1 part by weight, the effect of improving the weather resistance may be insufficient, and if the amount exceeds 20 parts by weight, a coloring problem may occur and the appearance as a sealing material may be impaired.

(Other additives)
In the curable composition of the present invention, as long as the effects of the present invention are not impaired, a curing accelerator for the curable composition, a viscosity modifier for adjusting the viscosity properties of the composition, a thixotropic agent, and a tensile property are improved. Physical property modifiers, extenders, reinforcing agents, plasticizers, coloring agents, flame retardants, ultraviolet absorbers, light stabilizers, antioxidants, anti-sagging agents, anti-aging agents, solvents, fragrances, pigments, dyes, dehydrating agents, etc. May be added.

  As the curing accelerator, for example, an organometallic compound can be used. As an organometallic compound that can be preferably used, an organometallic compound obtained by substituting an organic group with a metal element such as germanium, tin, lead, boron, aluminum, gallium, indium, titanium, and zirconium can be given. For example, dibutyltin dilaurate, dibutyltin oxide, dibutyltin diacetate, dibutyltin phthalate, bis (dibutyltin laurate) oxide, dibutyltin bisacetylacetonate, dibutyltin bis (monoester malate), tin octylate, dibutyl Tin compounds such as tin octoate and dioctyltin oxide; titanate compounds such as tetra-n-butoxytitanate and tetraisopropoxytitanate; these can be used alone or in combination of two or more.

  The viscosity modifier is selected, for example, from a polymer compound having good compatibility with the organic polymer (a), particularly, the vinyl polymer (a1), and is appropriately selected from compounds to be blended. For example, acrylic polymers, methacrylic polymers, polyvinyl alcohol derivatives, polyvinyl acetate, polystyrene derivatives, polyesters, polyethers, polyisobutene, polyolefins, polyalkylene oxides, polyurethanes, polyamides, natural rubber, polybutadiene , Polyisoprene, NBR, SBS, SIS, SEBS, hydrogenated NBR, hydrogenated SBS, hydrogenated SIS, hydrogenated SEBS, and the like. In addition, these copolymers and modified functional groups can be exemplified, and these may be appropriately combined.

  The thixotropic agent is appropriately selected from substances that cause the composition to exhibit thixotropic properties. For example, colloidal silica, polyvinylpyrrolidone, hydrophobized calcium carbonate, glass balloon, glass beads and the like can be mentioned. Regarding the selection of the thixotropic agent, a thixotropic agent desirably has a surface having a high affinity for the vinyl polymer (a1).

  As a physical property modifier for improving tensile properties, various silane coupling agents, for example, vinyltrimethoxysilane, dimethyldimethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, tetramethoxysilane, tetraethoxysilane, phenyltrimethoxysilane Silane, diphenyldimethoxysilane, 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] ethylene Amines, N, N'-bis- [3- (trimethoxysilyl) propyl] hexaethylenediamine, N, N'-bis- [3- (triethoxysilyl) propyl] hexaethylenediamine, and the like. Two or more kinds may be used in combination.

  As the bulking agent, those which do not exhibit thixotropic properties when added to the composition according to the present invention can be suitably used.For example, talc, clay, calcium carbonate, magnesium carbonate, anhydrous silicon, hydrous silicon, calcium silicate, Titanium dioxide, carbon black and the like can be mentioned, and these may be used alone or in combination of two or more.

  Examples of the plasticizer include phosphates such as tributyl phosphate and tricresyl phosphate; phthalates such as dioctyl phthalate; fatty acid-basic acid esters such as glycerin monooleate; and dioctyl adipate. Examples thereof include fatty acid dibasic acid esters and polypropylene glycols, which may be used alone or in combination of two or more.

Further, an adhesive and a sealing material comprising the above-mentioned curable composition are also one of the present invention.
Further, a joint structure using the above-mentioned sealing material is also one of the present invention. In this case, it is preferable to use a sealing material having a dumbbell-shaped elongation of 1000%. When the elongation is 1000% or more, it is possible to follow a change in elongation of a base material, a tile, or the like constituting the joint structure, absorb the change in elongation, and configure a joint structure having excellent durability. Here, the elongation of the dumbbell shape is a breaking elongation (%) obtained by performing a tensile test using a No. 3 dumbbell in accordance with JIS K 6301 at a crosshead speed of 500 mm / min.

  In the curable composition according to the present invention, the organic polymer (a) having a hydrolyzable silyl group and the organic polymer having at least a carboxyl group and having the same main chain structure as the organic polymer (a) Since it contains the organic polymer (b) having a chain structure, it is possible to provide a curable composition that is cured by moisture in the atmosphere and has excellent elongation of the cured product.

  Therefore, the curable composition according to the present invention can provide a sealing material, a coating material, or an adhesive that can be suitably used for a sealing portion, a coating portion, or an adhesive portion that needs to absorb strain. Become.

  Hereinafter, the present invention will be described in more detail by describing specific examples of the present invention. Note that the present invention is not limited to the following embodiments.

(Preparation of Polymer (a1) Having Hydrolyzable Silyl Group)
In a 2 L separable flask equipped with a stirrer, a cooler, a thermometer and a nitrogen gas inlet, 100 g of n-butyl acrylate and 3-methacryloyloxypropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., product number: KBM-503) 5 g, 0.2 g of 3-mercaptopropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., product number: KBM-803), 0.1 g of lauryl mercaptan (manufactured by Wako Pure Chemical Industries) and 100 g of ethyl acetate were charged and mixed.

  After the dissolved oxygen was removed by bubbling the monomer mixed solution with nitrogen gas for 20 minutes, the inside of the separable flask system was replaced with nitrogen gas, and the temperature was raised to reach reflux while stirring. After the start of reflux, a solution prepared by diluting 0.024 g of 1,1-di (t-hexylperoxy) -3,3,5-trimethylcyclohexane with 1 g of ethyl acetate as a polymerization initiator was charged into the polymerization system. One hour later, a solution obtained by diluting 0.036 g of 1,1-di (t-hexylperoxy) -3,3,5-trimethylcyclohexane with 1 g of ethyl acetate was added. Further, two, three and four hours after the start of the polymerization, a solution obtained by diluting 0.048 g, 0.12 g, and 0.36 g of di (3,5,5-trimethylhexanoyl) peroxide with 1 g of ethyl acetate was added. I put it in. Seven hours after the first addition of the polymerization initiator, the mixture was cooled to room temperature to terminate the polymerization, thereby obtaining an ethyl acetate solution of the polymer (a1) having a hydrolyzable silyl group.

The number average molecular weight (molecular weight in terms of polystyrene measured by gel permeation chromatography) of the obtained polymer (a1) was about 30,000.
Further, the viscosity of the polymer (measured using a B-type rotary viscometer (Tokyo Keiki)) after removing ethyl acetate with a rotary evaporator was about 200 Pa · s at 25 ° C.

(Preparation of Polymer (a2) Having Hydrolyzable Silyl Group)
In a 2 L separable flask equipped with a stirrer, a cooler, a thermometer and a nitrogen gas inlet, 100 g of n-butyl acrylate and 3-methacryloyloxypropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., product number: KBM-503) 5 g, 0.2 g of 3-mercaptopropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., product number: KBM-803), 0.1 g of lauryl mercaptan (manufactured by Wako Pure Chemical Industries, Ltd.), 2,2-dimethoxy-1,2-diphenylethane 1 g of -1-one (Irgacure 651, manufactured by Ciba Specialty Chemical Co.) and 100 g of ethyl acetate were charged and mixed.
Dissolved oxygen was removed by bubbling the monomer mixed solution with nitrogen gas for 20 minutes, and then the inside of the separable flask system was replaced with nitrogen gas. After irradiation with ultraviolet light for 4 hours using a black light from the side of the separable flask, the mixture was cooled to room temperature and the polymerization was terminated to obtain an ethyl acetate solution of the polymer (a2) having a hydrolyzable silyl group.

The number average molecular weight (molecular weight in terms of polystyrene measured by gel permeation chromatography) of the obtained polymer (a2) was about 30,000.
Further, the viscosity of the polymer (measured using a B-type rotary viscometer (Tokyo Keiki)) after removing ethyl acetate with a rotary evaporator was about 200 Pa · s at 25 ° C.

(Preparation of vinyl polymer having carboxyl group (b1))
In a 0.5 L separable flask equipped with a stirrer, a cooler, a thermometer and a nitrogen gas inlet, 95 g of n-butyl acrylate (manufactured by Nippon Shokubai), 5 g of acrylic acid (manufactured by Wako Pure Chemical Industries), lauryl mercaptan (wa 4 g and 100 g of ethyl acetate were added and mixed. After the dissolved oxygen was removed by bubbling the obtained monomer mixed solution with nitrogen gas for 20 minutes, the inside of the separable flask system was replaced with nitrogen gas, and the temperature was raised until reflux was reached while stirring.

  After the start of reflux, a solution prepared by diluting 0.024 g of 1,1-di (t-hexylperoxy) -3,3,5-trimethylcyclohexane with 1 g of ethyl acetate as a polymerization initiator was charged into the polymerization system. One hour later, a solution obtained by diluting 0.036 g of 1,1-di (t-hexylperoxy) -3,3,5-trimethylcyclohexane with 1 g of ethyl acetate was added. Further, after 2, 3, and 4 hours from the start of the polymerization, a solution obtained by diluting 0.048 g, 0.12 g, and 0.36 g of di (3,5,5-trimethylhexanoyl) peroxide with 1 g of ethyl acetate was added. did. Seven hours after the first addition of the polymerization initiator, the mixture was cooled to room temperature and the polymerization was terminated to obtain an ethyl acetate solution of the polymer (b1) having a carboxyl group.

The number average molecular weight (molecular weight in terms of polystyrene measured by gel permeation chromatography) of the obtained polymer (b1) was 6,000.
The viscosity (measured using a B-type rotary viscometer (Tokyo Keiki)) of the polymer after removing ethyl acetate with a rotary evaporator was about 7 Pa · s at 25 ° C.

(Preparation 2 of vinyl polymer having carboxyl group (b2))
5. 100 g of polypropylene glycol (manufactured by Wako Pure Chemical Industries, average molecular weight: 3000) and maleic anhydride (manufactured by Wako Pure Chemical Industries) in a 0.5 L separable flask equipped with a stirrer, a cooler, a thermometer and a nitrogen gas inlet. 6 g was charged and heated to 80 ° C. using a warm water bath. After the system became homogeneous, the reaction was carried out at 80 ° C. for 6 hours to obtain carboxylic acid-terminated polypropylene (b2).
The viscosity (measured using a B-type rotational viscometer (Tokyo Keiki)) of the obtained polypropylene glycol (b2) was about 3 Pa · s at 25 ° C. In the following examples, they were used without purification.

(Preparation of acrylic polymer (X) having no polar functional group)
100 g of n-butyl acrylate (manufactured by Nippon Shokubai), 4.0 g of lauryl mercaptan (manufactured by Wako Pure Chemical Industries), and 100 g of ethyl acetate were placed in a 2 L separable flask equipped with a stirrer, a cooler, a thermometer and a nitrogen gas inlet. Charged and mixed. After the dissolved oxygen was removed by bubbling the monomer mixed solution with nitrogen gas for 20 minutes, the inside of the separable flask system was replaced with nitrogen gas, and the temperature was raised with stirring to reach the reflux. After the start of reflux, a solution prepared by diluting 0.024 g of 1,1-di (t-hexylperoxy) -3,3,5-trimethylcyclohexane with 1 g of ethyl acetate as a polymerization initiator was charged into the polymerization system. One hour later, a solution obtained by diluting 0.036 g of 1,1-di (t-hexylperoxy) -3,3,5-trimethylcyclohexane with 1 g of ethyl acetate was added. Further, after 2, 3 and 4 hours from the start of the polymerization, a solution obtained by diluting 0.048 g, 0.12 g, and 0.36 g of di (3,5,5-trimethylhexanoyl) peroxide with 1 g of ethyl acetate was added. did. Seven hours after the first addition of the polymerization initiator, the mixture was cooled to room temperature to terminate the polymerization, thereby obtaining a solution of the low molecular weight acrylic polymer (X) in ethyl acetate.
The number average molecular weight (molecular weight in terms of styrene measured by gel permeation chromatography) of the obtained polymer (X) was 5,800.
The viscosity (measured using a rotational viscometer (Tokyo Keiki)) after removing ethyl acetate with a rotary evaporator was about 5 Pa · s at 25 ° C.

(Example 1)
After 160 g of an ethyl acetate solution of the alkoxysilyl group-containing acrylic polymer (a1) obtained above and 40 g of an ethyl acetate solution of the carboxyl group-containing acrylic polymer (b1) were mixed, ethyl acetate was removed using a rotary evaporator. This was removed to obtain a viscous liquid composition. The viscosity of this composition at 25 ° C. was about 300,000 cps.

  70 g of heavy calcium carbonate, 30 g of fatty acid-treated calcium carbonate, and 3 g of a hardening accelerator (dibutyltin dilaurate) are further added to the liquid composition obtained as described above, and mixed with a sealed stirrer until uniform. Then, the mixture was defoamed under reduced pressure for 10 minutes to obtain a curable composition in the form of a white paste.

  The obtained curable composition is applied on a polyethylene plate so as to have a thickness of 2.5 mm, and then cured under an environment of 20 ° C. and a relative humidity of 50% for 7 days to obtain a rubber-like sheet. Got.

The obtained rubber-like sheet was subjected to a tensile test at a crosshead speed of 500 mm / min in a No. 3 dumbbell shape in accordance with JIS K 6301, and a breaking elongation (%) and a breaking stress (N / mm ² ) were obtained. The results are shown in Table 1.

(Examples 2 to 5 and Comparative Examples 1 to 3)
A rubber-like sheet was obtained in the same manner as in Example 1 except that the mixing ratio of each component was changed as shown in Tables 1 and 2 below. A tensile test was performed on the obtained rubber-like sheet in the same manner as in Example 1. The results are shown in Tables 1 and 2.

(Example 6)
In Example 1, at the time of preparing the curable composition, 10 g of a layered silicate (Somasif MPE-100, swellable fluorine mica organically treated with a polyoxypropylene diethyl quaternary ammonium salt, manufactured by Corp Chemical Co., Ltd.), tinuvin 770 ( Curable composition in the same manner as in Example 1 except that 5 g of a hindered amine light stabilizer, Ciba Specialty Chemicals) and 5 g of Tinuvin 327 (benzotriazole ultraviolet absorber, Ciba Specialty Chemicals) were added. Got.

(Measurement of average interlayer distance of layered silicate)
The average interlayer distance of the layered silicate in the curable composition obtained in Example 5 was measured as follows.

  Using an X-ray diffractometer (Rigaku Corporation, RINT1100), 2θ of a diffraction peak obtained by diffraction of the layered silicate layer surface was measured, and the (001) of the layered silicate was determined using the following black diffraction equation. ) The spacing (d) was calculated from the following equation. The following d was taken as the average interlayer distance, and the average interlayer distance was 3 nm or more and was well dispersed.

λ = 2d sin θ
In the formula, λ (nm) = 0.154, d (nm) is a plane interval of the layered silicate, and θ (degree) is a diffraction angle.

(Confirmation of dispersion state of layered silicate)
When the dispersion state of the layered silicate in the cured product was observed by a transmission electron microscope (TEM JEM-1200EX II, manufactured by JEOL Ltd.) photograph, it was found that there were not more than 5 layers.

(Weather resistance evaluation)
The curable compositions obtained in Examples 1 and 5 were applied to a 50 mm × 150 mm (thickness: 1 mm) stainless steel plate at a thickness of 0.5 mm, and were placed in an atmosphere of 20 ° C. × 60% RH for 7 days (168 hours). After being left to cure and harden, light irradiation was performed for 150 hours and 400 hours under the following conditions, and the surface state was visually checked. The results are shown in Table 3.

Light irradiation conditions Test apparatus: Eye Super UV tester (SUV-F11 type), manufactured by Iwasaki Electric Co., Ltd. Irradiation intensity: 100 mW / cm2 Limited wavelength: 295 nm to 450 nm
Black panel temperature: 63 ° C Irradiation distance: 235 mm (between light source and sample)
(Evaluation of light irradiation by the Eye Super UV tester cannot be said unconditionally because it varies depending on the material system and test conditions, but it has a severe acceleration effect that is about 10 times higher than the evaluation by a normal sunshine weatherometer. It is.)

(Example 7)
Two sizing boards (300 mm × 300 mm) were set on a plywood with a gap of 10 mm. The composition obtained in Example 1 was filled in the provided gap using an application gun, and cured at 23 ° C. for 7 days. Thus, a joint structure was obtained using the composition obtained in Example 1. The obtained structure was subjected to 500 cycles of a thermal cycle test at 40 ° C. × 6 hours and then at 0 ° C. × 6 hours. No cracks or cracks were visually observed in the joint structure.

The schematic diagram for demonstrating the crystal surface (A) and crystal end surface (B) of the flaky crystal of a layered silicate. The schematic diagram for demonstrating the exchangeable cation between layers of a layered silicate.

Claims (14)

  An organic polymer (a) containing at least a crosslinkable hydrolyzable silyl group, and an organic polymer (b) having substantially the same main chain structure as the organic polymer (a) and having at least a polar group. A curable composition comprising:   The curable composition according to claim 1, wherein the polar group is a carboxyl group.   The main chain structure of the organic polymer (a) is a polyether, polyester, polycarbonate, polyurethane, polyamide, polyurea, polyimide, polysiloxane, a vinyl-based polymer obtained by polymerizing a polymerizable unsaturated group, and these structures. The curable composition according to claim 1, wherein the curable composition is one selected from the group consisting of a main chain structure obtained in combination.   The curable composition according to claim 3, wherein the organic polymer (a) is a vinyl polymer (a1).   The curable composition according to claim 4, wherein the vinyl polymer (a1) is a vinyl polymer synthesized by radical polymerization using a peroxide as a polymerization initiator.   The curable composition according to claim 5, wherein the vinyl polymer (a1) is a (meth) acrylate polymer.   The curable composition according to claim 6, wherein the (meth) acrylate polymer is a polymer synthesized by irradiating ultraviolet rays.   The curable composition according to any one of claims 4 to 7, further comprising a polyether polymer (c) having at least a crosslinkable hydrolyzable silyl group.   The curability according to any one of claims 1 to 8, wherein the viscosity of at least one of the organic polymer (a) and the organic polymer (b) at 25 ° C is 0.01 to 500 Pa · s. Composition.   The curable composition according to any one of claims 1 to 9, further comprising a layered silicate.   The curable composition according to any one of claims 1 to 10, wherein the cured product is rubbery at 0 to 40 ° C.   A sealing material comprising the curable composition according to claim 1.   An adhesive comprising the curable composition according to claim 1. A joint structure obtained by using the sealing material according to claim 12, wherein the cured product of the sealing material has a dumbbell-shaped elongation at break of 1000% or more.

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