JP4353747B2 - Curable composition - Google Patents

Description

  The present invention relates to a curable composition, and more particularly to a curable composition having excellent curability and water resistance.

  A room temperature curable composition containing a crosslinkable silyl group-containing organic polymer has already been industrially produced and widely used in applications such as sealing materials, adhesives and paints. Usually, these curable compositions are cured using various metal catalysts, and are used for various applications depending on the type and amount of addition.

  As the catalyst, a reaction product of organotin and an ester compound is conventionally known (see, for example, Patent Documents 1 to 4). Among the ester compounds, in particular, a catalyst using a phthalate ester is generally used. This phthalate ester is stipulated as a VOC guideline formulation substance by the Ministry of Health, Labor and Welfare, and its existence has been pointed out. In recent years, catalyst design with non-phthalate esters has been demanded.

In addition, as described above, the crosslinkable silyl group-containing organic polymer is used as a sealing material or an adhesive. Problems can occur. In addition, when excessive heat is applied due to direct sunlight or an increase in the outside air temperature, the crosslinking gradually proceeds, the hardness increases, the flexibility is lost, the movement of the adherend cannot be followed, and the breakage occurs. Problems such as water leakage may occur.
Japanese Patent Publication No. 1-58219 Japanese Patent No. 3062625 JP-A-8-337713 JP 2003-138151 A Japanese Patent Laid-Open No. 11-12480 JP-A-52-73998 JP 55-9669 A JP 59-122541 A Japanese Unexamined Patent Publication No. 60-6747 JP-A-61-233043 Japanese Unexamined Patent Publication No. Sho 63-112642 JP-A-3-79627 JP-A-4-283259 JP-A-5-70531 JP-A-5-287186 Japanese Patent Laid-Open No. 11-80571 Japanese Patent Laid-Open No. 11-116763 JP-A-11-130931 Japanese Patent Laid-Open No. 2001-40037 Japanese Patent No. 3313360

  The present invention has been made in view of the above-described problems of the prior art, and an object thereof is to provide a curable composition having high safety and excellent curability and water resistance.

In order to solve the above problems, the curable composition of the present invention comprises (A) a crosslinkable silyl group-containing organic polymer, and (B) general formula (1): R ¹ R ² SnO (1). (In formula 1, R ¹ and R ² are each a monovalent hydrocarbon group) an organotin (I) and a (meth) acrylic polymer (II) having a number average molecular weight of 500 to 50,000 , A tin compound obtained by charging the (meth) acrylic polymer (II) in a proportion of 0.5 to 30 parts by weight with respect to 1 part by weight of organic tin (I), and heating and stirring , and (D ) A silane coupling agent , and 0.01 to 50 parts by weight of the (B) tin compound with respect to 100 parts by weight of the (A) crosslinkable silyl group-containing organic polymer, and (D) the silane coupling. 0.1-30 weight part of an agent is mix | blended , It is characterized by the above-mentioned.

  The component (A) is a crosslinkable silyl group-containing polyoxyalkylene polymer, a crosslinkable silyl group-containing (meth) acryl-modified polyoxyalkylene polymer, a crosslinkable silyl group-containing polyisobutylene polymer, and a crosslinkable silyl group-containing polymer. It is preferably at least one compound selected from the group consisting of (meth) acrylic polymers.

  The (meth) acrylic polymer (II) is preferably a (meth) acrylic acid ester-fluoroolefin copolymer.

  The (meth) acrylic polymer (II) was selected from the group consisting of a crosslinkable silyl group-containing (meth) acryl-modified polyoxyalkylene polymer and a crosslinkable silyl group-containing (meth) acrylic polymer. It is preferred that it is at least one compound.

  It is preferable to further add (C) an organic polymer (III) having a number average molecular weight of 2,000 to 50,000 to the curable composition of the present invention.

  The component (C) is preferably a polyoxyalkylene polymer having a number average molecular weight of 4,000 to 50,000 and a weight average molecular weight (MW) / number average molecular weight (Mn) of 1.5 or less. Moreover, it is preferable that the said component (C) is a (meth) acrylic-type polymer. Furthermore, it is preferable that the said component (C) is a (meth) acrylic acid ester-fluoro olefin copolymer.

  It is preferable to further add (D) a silane coupling agent to the curable composition of the present invention.

  According to the present invention, it is possible to provide a curable composition having high safety and excellent curability and water resistance.

  Embodiments of the present invention will be described below, but these embodiments are exemplarily shown, and it goes without saying that various modifications are possible without departing from the technical idea of the present invention.

The curable composition of the present invention is characterized by containing the following components (A) and (B).
(A) Crosslinkable silyl group-containing organic polymer (B) General formula (1): R ¹ R ² SnO (1)
(In formula 1, R ¹ and R ² are each a monovalent hydrocarbon group) and the (meth) acrylic polymer (II) having a number average molecular weight of 500 to 50,000 is reacted. Tin compounds obtained

  As the component (A), a silicon-containing group having a hydroxyl group or a hydrolyzable group bonded to a silicon atom and capable of crosslinking by forming a siloxane bond, that is, an organic polymer containing a crosslinkable silyl group is used. Is done. Examples of the crosslinkable silyl group-containing organic polymer (A) include those disclosed in Patent Documents 1 to 20. Specifically, the crosslinkable silyl group-containing organic polymer (A) includes one or more crosslinkable silyl groups in the molecule, the main chain may each contain an organosiloxane, Examples thereof include oxyalkylene polymers, vinyl-modified polyoxyalkylene polymers, vinyl polymers, polyester polymers, acrylic acid ester polymers, methacrylic acid ester polymers, copolymers and mixtures thereof.

  It is preferable that 1-6 crosslinkable silyl groups are contained in a molecule | numerator from points, such as the curability of a sealing material, and the physical property after hardening. Further, the crosslinkable silyl group is preferably one represented by the following general formula (2) which is easily crosslinked and easy to produce.

(In formula (2), R ³ is a monovalent organic group having a substituted or unsubstituted 1 to 20 carbon atoms, an alkyl group having 1 to 20 carbon atoms, an aryl group or a carbon of 6 to 20 carbon atoms 7 An aralkyl group of ˜20 is preferred, and a methyl group is most preferred, and when a plurality of R ³ are present, they may be the same or different, X is a hydroxyl group or a hydrolyzable group, a halogen atom, hydrogen A group selected from an atom, a hydroxyl group, an alkoxy group, an acyloxy group, a ketoximate group, an amide group, an acid amide group, a mercapto group, an alkenyloxy group and an aminooxy group is preferred, an alkoxy group is more preferred, and a methoxy group is most preferred. When a plurality of X are present, they may be the same or different, and a is 0, 1 or 2.

  In the crosslinkable silyl group-containing organic compound (A), when a plurality of crosslinkable silyl groups are present, these may be the same or different, and the number of a in the formula (2) is also the same. Or different.

  The main chain of the crosslinkable silyl group-containing organic polymer (A) is a polyoxyalkylene polymer which may contain an organosiloxane from the viewpoint of physical properties such as tensile adhesiveness after curing and modulus. A (meth) acryl-modified polyoxyalkylene polymer, a polyisobutylene polymer, a (meth) acrylic polymer, a copolymer or a mixture thereof, and the like are preferable.

  In the present invention, the crosslinkable silyl group-containing organic polymer (A) has a number average molecular weight of 1,000 or more and 100,000 or less, more preferably 3000 to 50000 and a narrow molecular weight distribution, which is easy to handle because the viscosity before curing is low, Properties such as strength, elongation and modulus after curing are suitable. The said crosslinkable silyl group containing organic polymer (A) may be used only by 1 type, and may be used together 2 or more types.

In the present invention, the organic tin (I) used in the component (B) has the general formula (1): R ¹ R ² SnO (1) (wherein R ¹ and R ² are each monovalent. Hydrocarbon group). The monovalent hydrocarbon group for R ¹ and R ² is not particularly limited, and examples thereof include a methyl group, an ethyl group, a propyl group, a butyl group, an amyl group, a dodecyl group, a lauryl group, a propenyl group, a phenyl group, A suitable example is a hydrocarbon group having about 1 to 20 carbon atoms such as a tolyl group. R ¹ and R ² may be the same or different. As the organic tin, dialkyltin oxide such as dimethyltin oxide, dibutyltin oxide and dioctyltin oxide is particularly preferable.

  In the present invention, the (meth) acrylic polymer (II) used in the component (B) is not particularly limited as long as it is a (meth) acrylic polymer having a number average molecular weight of 500 or more and 50000 or less. Is an acrylic monomer such as (meth) acrylic acid, (meth) acrylic acid ester, (meth) acrylonitrile, (meth) acrylamide, etc., which may contain a crosslinkable silyl group. Examples thereof include a composition comprising as a main component a compound that is a polymer obtained by (co) polymerizing one or more kinds or a mixture thereof. Although it does not specifically limit as said acrylic monomer, (meth) acrylic acid ester is preferable. The (meth) acrylic polymer may be used alone or in combination of two or more.

  Examples of the acrylate ester include methyl (meth) acrylate, ethyl (meth) acrylate, (meth) acrylate-n-propyl, isopropyl (meth) acrylate, (meth) acrylate-n-butyl, (Meth) acrylic acid isobutyl, (meth) acrylic acid s-butyl, (meth) acrylic acid t-butyl, (meth) acrylic acid-n-pentyl, (meth) acrylic acid neopentyl, (meth) acrylic acid-n- Hexyl, (meth) acrylic acid-n-heptyl, (meth) acrylic acid-n-octyl, (meth) acrylic acid 2-ethylhexyl, (meth) acrylic acid nonyl, (meth) acrylic acid decyl, (meth) acrylic acid Isodecyl, dodecyl (meth) acrylate, lauryl (meth) acrylate, tridecyl (meth) acrylate and (meth) Alkyl (meth) acrylates such as stearyl acrylate; alicyclic alkyl acrylates such as cyclohexyl (meth) acrylate, isobornyl (meth) acrylate and tricyclodecynyl (meth) acrylate; phenyl (meth) acrylate , Aromatic acrylic esters such as toluyl (meth) acrylate and benzyl (meth) acrylate, hydroxyethyl (meth) acrylate, hydroxybutyl (meth) acrylate, hydroxypropyl (meth) acrylate and (meth) Hydroxyalkyl (meth) acrylate such as ε-caprolactone addition reaction product of hydroxyethyl acrylate; 2-methoxyethyl (meth) acrylate, 3-methoxybutyl (meth) acrylate, 2-aminoethyl (meth) acrylate , Dimethylamino (meth) acrylate Examples include heteroatom-containing acrylic esters such as ethyl, chloroethyl (meth) acrylate, trifluoroethyl (meth) acrylate, trifluoromethyl methyl (meth) acrylate, and tetrahydrofurfuryl (meth) acrylate. Not limited to these. Moreover, you may use together 1 type, or 2 or more types of these. Among the above (meth) acrylic acid esters, butyl acrylate, 2-ethylhexyl acrylate and 2-methoxyethyl acrylate are preferred because a polymer having a low glass transition temperature is obtained.

  In addition, as the (meth) acrylic polymer (II), in addition to the acrylic monomer, a monomer copolymerizable therewith can be copolymerized. The copolymerizable monomer is not particularly limited, and examples thereof include vinyl monomers such as fluoroolefins, α-olefins, vinyl esters and vinyl ethers, and (meth) acrylic acid ester- A fluoroolefin copolymer is particularly preferred. As the (meth) acrylic polymer (II), a (meth) acrylic polymer having a crosslinkable silyl group and a (meth) acryl-modified polyoxyalkylene polymer are preferably used.

  A conventionally well-known thing can be widely used as a (meth) acrylic ester-fluoro olefin copolymer. Examples of the fluoroolefin monomer include tetrafluoroethylene, chlorotrifluoroethylene, hexafluoropropylene, dichlorodifluoroethylene, trifluoroethylene, vinylidene fluoride, vinyl fluoride and perfluoro (alkyl vinyl ether). Among these, tetrafluoroethylene, chlorotrifluoroethylene, hexafluoropropylene and trifluoroethylene are preferable from the viewpoint of polymerizability, and tetrafluoroethylene, chlorotrifluoroethylene and trifluoroethylene are more preferable.

  The method for obtaining the curing catalyst as the component (B) by reacting the organotin (I) with the (meth) acrylic polymer (II) is not particularly limited, and a conventionally known method can be used. . Below, an example of the method of obtaining organotin (I) and the (meth) acrylic-type polymer (II) and obtaining a tin compound is demonstrated easily. Organotin and (meth) acrylic polymer are charged into a container equipped with a stirrer at a predetermined ratio, and heated and stirred. This facilitates the reaction. The end point may be determined by changing the mixture of the two into a transparent liquid having a brown color. The reaction can be carried out at any temperature from room temperature to 200 ° C, but more preferable results can be obtained when the reaction is carried out at a temperature of 100 to 150 ° C.

  The mixing ratio of the organic tin (I) and the (meth) acrylic polymer (II) is not particularly limited, but the (meth) acrylic polymer (II) is 0.5 to 1 part by weight of the organic tin (I). It is preferable to make it react 30 weight part, Especially preferably, it is 1-20 weight part. If the amount is less than 0.5 part by weight, the tendency to solidify during the reaction is large, and it is not easy to uniformly disperse in the composition as a catalyst, and if it exceeds 30 parts by weight, the effect as an additive is hardly exhibited. Therefore, it is not preferable.

  The blending ratio of component (B) is not particularly limited, but it is preferably 0.01 to 50 parts by weight, more preferably 0.02 to 30 parts by weight, based on 100 parts by weight of component (A). The tin compound may be used alone or in combination of two or more.

  It is preferable from the viewpoint of workability, curability, flexibility of the cured product, and the like that (C) an organic polymer (III) having a number average molecular weight of 2000 to 50000 is further added to the curable composition of the present invention. .

  The component (C) organic polymer (III) is not particularly limited as long as it is an organic polymer having a number average molecular weight of 2,000 or more and 50,000 or less. Specifically, it may contain a crosslinkable silyl group. , Polyoxyalkylene polymers, vinyl-modified polyoxyalkylene polymers, vinyl polymers, polyester polymers, (meth) acrylic polymers, copolymers and mixtures thereof. In particular, a polyoxyalkylene polymer having a number average molecular weight of 4,000 to 50,000 and a weight average molecular weight (MW) / number average molecular weight (Mn) of 1.5 or less, or a (meth) acryl having a number average molecular weight of 2,000 to 50,000. Preferable examples include a polymer, a (meth) acrylic acid ester-fluoroolefin copolymer having a number average molecular weight of 2000 or more and 50000 or less, a copolymer or a mixture thereof.

  A polyoxyalkylene polymer having a number average molecular weight of 4,000 to 50,000 and a weight average molecular weight (Mw) / number average molecular weight (Mn) of 1.5 or less, preferably used as the component (C). The polyoxypropylene polymer (C1) may be referred to as an initiator such as a hydroxy compound having at least one hydroxyl group in the presence of a catalyst such as an alkali metal catalyst, a double metal cyanide complex catalyst, or a metal porphyrin catalyst. It can be produced by reacting a monoepoxide such as alkylene oxide.

  Specific examples of the initiator include ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, neopentyl glycol, 1,4-butanediol, 1,6-hexanediol, glycerin, trimethylolpropane, pentaerythritol, diglycerin. , Sucrose and polyols having a lower molecular weight than the target product obtained by reacting these with alkylene oxide. These may be used alone or in combination of two or more. Also, unsaturated group-containing monohydroxy compounds such as allyl alcohol can be used.

  Particularly preferred polyoxyalkylene polymers (C1) are polyoxypropylene diol, polyoxyalkylene triol and polyoxytetraol.

  Moreover, the polyoxyalkylene polymer which converted the hydroxyl group which the polyoxyalkylene polymer has into another group can also be used. As an example of a polymer in which a hydroxyl group is converted to another group in this way, a polyoxyalkylene polymer having a terminal hydroxyl group such as oxypropylene glycol has a bond such as a urethane bond, an ester bond, a urea bond, or a carbonate bond. Through, substitution of alkyl groups such as methyl group, ethyl group, propyl group, chloromethyl group, benzyl group and glycidyl group, aryl groups such as phenyl group, toluyl group and chlorophenyl group, and alkenyl groups such as vinyl group and allyl group Or the oxyalkylene polymer blocked with the unsubstituted hydrocarbon group, Preferably the C1-C40 hydrocarbon group is mentioned.

  Specific examples of the (meth) acrylic polymer and (meth) acrylic acid ester-fluoroolefin copolymer that are suitably used as the component (C) include the (meth) acrylic polymer of the component (B). Those described above in (II) can be used in the same manner (however, the number average molecular weight is limited to 2000 to 50000).

  Although the compounding ratio of a component (C) is not specifically limited, It is preferable to use 1-400 weight part with respect to 100 weight part of component (A), and it is more preferable to use 5-200 weight part. The said component (C) may be used only by 1 type, and may be used together 2 or more types.

  It is preferable to further add a component (D) silane coupling agent to the curable composition of the present invention in order to improve adhesion and accelerate curing. As the silane coupling agent, conventionally known silane coupling agents can be widely used and are not particularly limited. For example, aminosilanes such as aminoethylaminopropyltrimethoxysilane, aminoethylaminopropylmethyldimethoxysilane, aminoethylaminopropylmethylmethoxysilane, and the like. , Epoxy silanes such as γ-glycidoxypropyltrimethoxysilane, acrylic silanes such as γ-methacryloxypropyltrimethoxysilane, mercaptosilanes such as γ-mercaptopropyltrimethoxysilane, γ-isocyanatopropyltrimethoxysilane And isocyanate silanes.

Although the compounding ratio of a component (D) is not specifically limited, About 0.1-30 weight part of a component ( D ) is preferable with respect to 100 weight part of a component (A), 0.2-20 weight part is further more preferable. . These silane coupling agents may be used alone or in combination of two or more.

  In addition to the above-described components, the curable composition of the present invention includes a physical property adjuster, a filler, a plasticizer, a thixotropic agent, a dehydrating agent (storage stability improving agent), a tackifier, and a sagging agent as necessary. You may mix | blend substances, such as an inhibitor, a ultraviolet absorber, antioxidant, a flame retardant, a coloring agent, and a radical polymerization initiator, and various solvents, such as toluene and alcohol.

  Examples of the filler include calcium carbonate, magnesium carbonate, diatomaceous earth hydrous silicic acid, hydrous silicic acid, anhydrous silicic acid, calcium silicate, silica, titanium dioxide, clay, talc, carbon black, slate powder, mica, kaolin, and zeolite. Of these, calcium carbonate is preferable, and fatty acid-treated calcium carbonate is more preferable. In addition, glass beads, silica beads, alumina beads, carbon beads, styrene beads, phenol beads, acrylic beads, porous silica, shirasu balloons, glass balloons, silica balloons, saran balloons, acrylic balloons, etc. can be used. Among them, an acrylic balloon is more preferable from the viewpoint that the decrease in elongation after curing of the composition is small. The fillers may be used alone or in combination of two or more.

  The present invention will be described more specifically with reference to the following examples. However, it is needless to say that these examples are shown by way of illustration and should not be construed in a limited manner.

(Synthesis Example 1)
A flask with a stirrer with 500 ml was charged with 25 g of dibutyltin oxide (trade name, STANNBO: manufactured by Sansha Co., Ltd.) and 125 g of an acrylic polymer (trade name, UP-1000: manufactured by Toagosei Co., Ltd.) at 130 ° C. In an oil bath for 3 hours. The mixture was initially a white slurry, but as the reaction proceeded, it finally became a viscous brown transparent liquid, and the desired dibutyltin oxide / acrylic polymer (1/5) reactant was obtained.

(Example 1)
As shown in Table 1, the crosslinkable silyl group-containing organic polymer (* 1), acrylic polymer (* 3), anti-aging agent (* 5), calcium carbonate (* 6), and vinyltrimethoxysilane Each of them was charged in a predetermined amount, and the mixture was stirred under reduced pressure at 110 ° C. for 2 hours to dehydrate the compounded substances. Furthermore, the aminosilane compound (* 4) and the reaction product obtained in Synthesis Example 1 were added to prepare a curable composition.

The compounding amounts of the compounding substances in Table 1 are shown in parts by weight, and (* 1 to * 7) are as follows.
* 1: Crosslinkable silyl group-containing polyoxypropylene polymer (manufactured by Kaneka Chemical Co., Ltd., trade name: SAT-200)
* 2: Crosslinkable silyl group-containing (meth) acrylic modified polyoxypropylene polymer (manufactured by Kaneka Chemical Co., Ltd., trade name MA440)
* 3: Acrylic polymer (trade name UP-1000, manufactured by Toagosei Co., Ltd.)
* 4: N-β (aminoethyl) γ-aminopropyltrimethoxysilane * 5: Ciba Specialty Chemicals Co., Ltd., trade name Tinuvin B75
* 6: Fatty acid-treated calcium carbonate (Maruo Calcium Co., Ltd., trade name Calfine 200M)
* 7: Trade name No. 918 (product of dibutyltin oxide and dioctyl phthalate), manufactured by Sansha Co., Ltd.

(Example 2)
As shown in Table 1, Example 1 except that the crosslinkable silyl group-containing organic polymer (* 2) was used instead of the crosslinkable silyl group-containing organic polymer (* 1) as the component (A). A curable composition was prepared by the same procedure.

(Comparative Example 1)
As shown in Table 1, in place of the reaction product obtained in Component (B) Synthesis Example 1, No. 918, which is a conventional curing catalyst, was used, and the total amount of acrylic polymer used was the same. Thus, the curable composition was adjusted by the same procedure as Example 1 except having changed the preparation amount.

  The following performance test was done about the obtained curable composition. The results are shown in Table 2.

1) Touch drying time About the obtained curable composition, touch drying time was measured according to JIS A1439 4.19.

2) Storage stability The viscosity was measured about the obtained curable composition. After leaving for 24 hours in an environment of 23 ° C. and 50% RH, the initial measurement was performed using a B-type viscometer (manufactured by Toki Sangyo, BS rotor No. 7 10 rpm), and then left in a dryer at 50 ° C. for 2 weeks. After that, it was allowed to stand for 24 hours in an environment of 23 ° C. and 50% RH, adjusted so that the liquid temperature became 23 ° C., and the viscosity was measured in the same manner. After storage / initial value is less than 1.3, ○ and 1.3 or more are evaluated as ×.

3) Adhesiveness Using the curable composition obtained above as an adherend, it was applied to anodized aluminum to a width of 30 mm, a length of 50 mm, and a height of 5 mm, and cured at 23 ° C. and 50% RH for 14 days for testing. Created a piece. After curing, the edge was cut with a cutter, and the curable composition was peeled off from the adherend by hand to evaluate the destruction state (initial). Moreover, after the test piece prepared by curing at 23 ° C. and 50% RH for 14 days was further immersed in 23 ° C. water for 7 days, a tensile test was performed to evaluate the fracture state (water resistance). The cohesive failure of the curable composition was evaluated as ◯, and the interface failure was evaluated as x.

  As shown in Table 2, Examples 1 and 2 were excellent in fast curability and storage stability, and had good initial adhesion and water resistance, whereas Comparative Example 1 had a problem with water resistance. Has occurred.

Since the curable composition of the present invention does not use a phthalate ester, it has a tremendous effect of being highly safe and having excellent curability and water resistance, and has a sealing material, an adhesive, an adhesive, and a coating. It can be suitably used as a material, a potting material or the like.

Claims (8)

(A) Crosslinkable silyl group-containing organic polymer, and (B) General formula (1): R ¹ R ² SnO (1)
(Wherein R ¹ and R ² are each a monovalent hydrocarbon group) and the (meth) acrylic polymer (II) having a number average molecular weight of 500 to 50,000 , A tin compound obtained by charging the (meth) acrylic polymer (II) into a container at a ratio of 0.5 to 30 parts by weight with respect to 1 part by weight of tin (I), and heating and stirring ; and
(D) a silane coupling agent , and 0.01 to 50 parts by weight of the (B) tin compound with respect to 100 parts by weight of the (A) crosslinkable silyl group-containing organic polymer, (D) A room temperature curable composition having adhesiveness, wherein 0.1 to 30 parts by weight of a silane coupling agent is blended .   The component (A) is a crosslinkable silyl group-containing polyoxyalkylene polymer, a crosslinkable silyl group-containing (meth) acryl-modified polyoxyalkylene polymer, a crosslinkable silyl group-containing polyisobutylene polymer, and a crosslinkable silyl group. The curable composition according to claim 1, wherein the curable composition is at least one compound selected from the group consisting of a containing (meth) acrylic polymer.   The curable composition according to claim 1 or 2, wherein the (meth) acrylic polymer (II) is a (meth) acrylic acid ester-fluoroolefin copolymer.   The (meth) acrylic polymer (II) was selected from the group consisting of a crosslinkable silyl group-containing (meth) acryl-modified polyoxyalkylene polymer and a crosslinkable silyl group-containing (meth) acrylic polymer. The curable composition according to claim 1, wherein the curable composition is at least one compound.   (C) Organic polymer (III) whose number average molecular weight is 2000 or more and 50000 or less is further added, The curable composition of any one of Claims 1-4 characterized by the above-mentioned.   6. The component (C) is a polyoxyalkylene polymer having a number average molecular weight of 4,000 to 50,000 and a weight average molecular weight (MW) / number average molecular weight (Mn) of 1.5 or less. The curable composition as described.   The curable composition according to claim 5, wherein the component (C) is a (meth) acrylic polymer.   6. The curable composition according to claim 5, wherein the component (C) is a (meth) acrylic acid ester-fluoroolefin copolymer.