JPH0220660B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to curable compositions. Curable resins containing a silyl group at the end are curable at room temperature and have excellent adhesion to glass, aluminum, etc., so they are used in sealants, paints, etc. by taking advantage of the characteristics of the resin in the main chain. As such resin, there is a urethane resin having a silyl group at the terminal or side chain. For example, as this urethane resin,
A urethane resin having an average of at least twice as many hydrolyzable silyl groups per molecule of the polymer obtained by the reaction of a urethane prepolymer having an NCO group and an active hydrogen-containing silane coupling agent 30711 and Japanese Unexamined Patent Publication No. 51-73561). However, although the cured coating film of urethane resin with terminal hydrolyzable silyl groups is relatively strong (high tensile strength), its hardness is relatively low, and the drying speed is relatively low, making it difficult to remove stickiness. There was a problem. The inventor of the present invention has conducted intensive studies to improve this problem, and as a result, has arrived at the present invention. That is, the present invention
A polyester polyol-based urethane prepolymer (A) whose NCO groups are capped with an active hydrogen-containing silane coupling agent or other monofunctional active hydrogen-containing compound, and one or more hydrolyzable silyl groups per polymer molecule. This is a curable composition characterized by containing a vinyl resin (B) containing: The blocked polyester polyol-based urethane prepolymer (A) used in the present invention is a polyester polyol having two or more NCO groups from a polyol containing a polyisocyanate and a polyester polyol, and optionally other active hydrogen-containing compounds. A structure obtained by reacting a urethane prepolymer (a), an active hydrogen-containing silane coupling agent (b), and, if necessary, a monofunctional active hydrogen-containing compound (c) can be used. Preferably, it has a structure obtained by reacting (a), (b), and (c). Polyisocyanates, polyols, other active hydrogen-containing compounds in NCO-terminated urethane polymer (a), reaction conditions to obtain (a), and (a), (b),
The reaction conditions for (c) are described in Japanese Patent Application No. 108349/1983. For example, in the NCO-terminated urethane prepolymer (a), the polyisocyanates include aliphatic polyisocyanates (such as hexamethylene diisocyanate) having 2 to 12 carbon atoms (excluding the carbon in the NCO group), and alicyclic polyisocyanates having 4 to 15 carbon atoms. Polyisocyanates (such as isophorone diisocyanate), aromatic aliphatic polyisocyanates having 8 to 12 carbon atoms (such as xylene diisocyanate), aromatic polyisocyanates (such as tolylene diisocyanate and diphenylmethane diisocyanate), and modified products of these polyisocyanates ( carbodiimide group,
(modified products containing uretdione groups, uretimine groups, urea groups, uret groups, and/or isocyanurate groups, etc.) can be used. Preferred among these polyisocyanates are aliphatic diisocyanates and alicyclic diisocyanates, and particularly preferred are hexamethylene diisocyanate and isophorone diisocyanate. Polyols include polymeric polyols [polyester polyols such as polycaprolactone polyol, polyether ester polyol; polyether polyols such as polyethylene glycol, polypropylene glycol and polytetramethylene glycol; preferred are polypropylene glycol, polytetramethylene glycol and polycaprolactone polyol, especially Preferred examples include polypropylene glycol and polycaprolactone polyol] and low-molecular polyols [low-molecular glycol and trifunctional or higher functional low-molecular polyol]. Among these polyols, polyester polyol is essential. Among the polyols, preferred are high-molecular polyols and combinations thereof with low-molecular polyols (the amount of low-molecular polyol is 0.001 to 30% by weight versus high-molecular polyol). The average molecular weight of the polyol is usually 62 to 4,000, preferably 200 to 2,000.
The OH value is usually 20-1000, preferably 30-800. Other active hydrogen-containing compounds that may be used if necessary include amines. When obtaining the NCO-terminated urethane prepolymer (a), the molar ratio of the NCO group of the polyisocyanate to the active hydrogen of the polyol and, if necessary, other active hydrogen-containing compounds is usually 1:0.1 to 1:0.9, preferably 1:0.3 to 1. :0.7. NCO-terminated NCO of NCO-terminated urethane prepolymer (a)
The number of groups per molecule is usually 2 to 6, preferably 2 to 4, and particularly preferably 2 to 3 on average. The average molecular weight of the NCO-terminated urethane prepolymer (a) is usually 200 to 40,000, preferably 500 to 20,000. The free NCO groups are usually 0.5 to 42% by weight, preferably 1 to 20% by weight, particularly preferably 2 to 8% by weight.
Weight%. The equivalent weight is usually 100-8400, preferably 210-4200, particularly preferably 525-2100. The active hydrogen-containing silane coupling agent (b) has an active hydrogen-containing group selected from the group consisting of a hydroxyl group, an amino group and a mercapto group, and a hydrolyzable silyl group selected from the group consisting of an alkoxysilyl group and a halosilyl group. Examples include compounds. Specifically, the general formula [In the formula, X ₂ is -O-, -S- or

[Formula] (where R ₄ is H or an alkyl group), R ₂ is an alkyl group, R ₃ is an alkoxy group or a halogen,
A ₂ is a divalent organic group. a is an integer from 0 to 2. ] Examples include compounds represented by: As a divalent organic group of A ₂ ,

【formula】

[Formula] or In the formula, p, q, r are integers of 0 or 1 or more,
Preferably 0 to 5, R ₅ and R ₆ are H, -(AO) _n ″H,
A′ is an alkylene group or

In [formula], Z is epoxy compound

It is a residue of [Formula]. R ₇ and R ₈ are amino compounds

It is a residue of [Formula]. m'' is an integer of 1 or more. Specific examples of (b) include the following: (1) Amino group-containing silane coupling agent Aminoalkyltrialkoxysilane (γ-
aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, aminomethyltriethoxysilane, etc.); N-(aminoalkyl)aminoalkyltrialkoxysilane [N
-(β-aminoethyl)aminomethyltrimethoxysilane, N-(β-aminoethyl)aminomethyltriethoxysilane, N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, etc.]; Aminoalkyldialkoxy Silane (aminomethylmethyldiethoxysilane, γ
-aminopropylmethyldiethoxysilane, etc.); N-aminoalkyl)aminoalkylalkyldialkoxysilane [N-(β-aminoethyl)-γ-aminopropylmethyldimethoxysilane, etc.]; and amino group-containing silane coupling agents and a partial hydrolyzate of a compound containing a hydrolyzable silyl group, such as the above amino group-containing silane coupling agent and a compound containing a hydrolyzable silyl group (ethylsilicate, methyltrimethoxysilane, methyltriethoxysilane, etc.). (2) Silane coupling agent containing a mercapto group Mercaptoalkylalkoxysilane (γ-
mercaptopropyltrimethoxysilane, etc.)
etc. (3) Hydroxyl group-containing silane coupling agents (1) Amino group-containing silane coupling agents and compounds containing epoxy groups (ethylene oxide, butylene oxide, epichlorohydrin, epoxidized soybean oil, and other Epicoat manufactured by Ciel Co., Ltd.)
828, Epicote 1001, etc.); epoxy group-containing silane coupling agents [glycidoxyalkyltrialkoxysilanes (γ-glycidoxypropyltrimethoxysilane, etc.); glycidoxyalkylalkyldialkoxysilanes (γ- glycidoxypropylmethyldimethoxysilane, etc.), amines such as aliphatic amines (ethylamine, diethylamine, triethylamine, ethylenediamine, hexamethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, etc.), aromatic amines ( Aniline, diphenylamines), aromatic amines (aniline, diphenylamines)
diphenylamines), alicyclic amines (cyclopentylamine, cyclohexylamine, etc.); reaction products with alkanolamines (ethanolamines), etc. Monofunctional active hydrogen-containing compounds (c) used as necessary include monofunctional sexual alcohols (aliphatic alcohols such as methanol, ethanol, n
-butanol, stearyl alcohol, etc.); their alkylene oxide (ethylene oxide, propylene oxide, etc.) adducts; monofunctional primary or secondary amines (aliphatic monoamines such as di-n
-butylamine, monobutylamine, etc.; aromatic monoamines such as aniline, monomethylaniline, etc.), alkylene oxides of the above secondary amines (ethylene oxide, propylene oxide, etc.)
Examples include additives. As a urethane prepolymer whose terminal NCO group is capped with an active hydrogen-containing silane coupling agent or this and other monofunctional active hydrogen-containing compounds, the general formula is (In the formula, Y is the residue of NCO-terminated urethane prepolymer Y (NCO) _f , Q is the silane coupling agent H
-X ₂ -A ₂ -Q residue, M is a monofunctional active hydrogen-containing compound H-X ₁ -A ₁ -M residue, f is the average number of functional groups in the prepolymer, 1≦≦f, preferably 1≦
<2, =f-. ) can be mentioned. In the composition of the present invention, the number of terminal hydrolyzable silyl groups in the urethane prepolymer (A) capped with an active hydrogen-containing silane coupling agent and, if necessary, a monofunctional active hydrogen-containing compound, is on average per polymer molecule. 1 to 2 pieces, preferably 1 to less than 2 pieces (for example, 1.9 pieces), particularly preferably 1.5 to 1.9 pieces. Number of terminal hydrolyzable silyl groups is 2 per molecule
When the number is more than 1, the hardness of the cured coating film of the composition is high, but it becomes brittle. If the number is less than one per molecule, the curing speed will be low and tack will likely remain. Furthermore, the tensile strength and hardness of the cured coating film are reduced. When blending a vinyl resin containing a terminal hydrolyzable silyl group with a terminal hydrolyzable silyl group number of 1 to 2 per molecule like the urethane prepolymer (A) of the present invention, the physical properties of the conventional urethane resin And it becomes possible to improve the drying speed. When obtaining the urethane prepolymer (A),
Taking into consideration the average number of NCO functional groups in the NCO-terminated urethane prepolymer (a), the silane cup is selected so that it has an average of 1 to 2 hydrolyzable silyl groups per molecule of the polymer (blocked urethane prepolymer). The amount of monofunctional active hydrogen-containing compound (c) is adjusted so that the ring agent (b) reacts. When (b) and (c) are used in combination, the reaction order may be arbitrary (simultaneously or separately, for example, reacting with the monofunctional active hydrogen-containing compound (c) and then reacting with the silane coupling agent (b)). . Also,
The NCO-terminated urethane prepolymer (a) may be produced by adding a silane coupling agent (b), a monofunctional active hydrogen-containing compound, etc. (c) during production. The reaction conditions are described in Japanese Patent Application No. 108349/1982. The average molecular weight of the blocked urethane prepolymer (A) is usually 500 to 40,000, preferably 800 to 20,000. Among the capped urethane prepolymers of the present invention, preferred are urethane prepolymers capped with active hydrogen-containing silane coupling agents and monofunctional active hydrogen-containing compounds. In the invention, the vinyl resin (B) having a hydrolyzable silyl group includes (i) a copolymer of a silyl compound having a polymerizable double bond and another vinyl monomer;
(ii) A reaction product of a vinyl resin having a carbon-carbon double bond and a hydrosilane compound (hydrosilylation reaction product) can be used. Silyl compounds with polymerizable double bonds and other vinyl monomers have the general formula (In the formula, Z' is a divalent organic group, R' is a C _1-12 alkyl group or an aryl group, R'' is a halogen group,
Compounds represented by an alkoxy group, an acyloxy group, an amide group, an aminoxy group, an alkenyloxy group, an amino group, an oxime group, or a thioalkoxy group ((b) is an integer of 0 to 2, and l is an integer of 0 to 1) can be given. In general formula (3), the divalent organic group of Z′ is −
Examples include COO-, -COO, -A''- (A'' is an alkylene group having 1 to 6 carbon atoms). As a compound having a polymerizable double bond,
Examples include those described in No. 58-108349. For example, examples of silyl compounds having a polymerizable double bond include vinylmethyldimethoxysilane, vinyltrimethoxysilane, vinyldichlorosilane, vinyltriethoxysilane, vinyltris(β-methoxyethoxy)silane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropylmethyldimethoxysilane, γ-
Acryloxypropyltrimethoxysilane, γ-
methacryloxypropylmethyldichlorosilane,
Examples include γ-acryloxytrichlorosilane. Other vinyl monomers that can be copolymerized with this silyl compound include those described in Japanese Patent Application No. 108349/1982, and briefly listed below. [] Lipophilic monomer (i) Esters of unsaturated carboxylic acids [(meth)acrylic acid, maleic acid, fumaric acid, itaconic acid, etc.] (ii) Aromatic hydrocarbon vinyl monomer (iii) Vinyl ester or (meth)allyl ester (iv) nitrile group-containing vinyl monomer (v) epoxy group-containing monomer (vi) halogen-containing vinyl monomer (vii) aliphatic hydrocarbon vinyl monomer (viii) vinyl ether Monomer (ix) Active hydrogen-containing vinyl monomer Hydroxyethyl (meth)acrylate, triethylene glycol (meth)acrylate, polyoxyethylene glycol mono(meth)allyl ether, N-methylol (meth)acrylamide, aminoethyl vinyl ether , mercaptopropyl (meth)acrylate, etc. [] Hydrophilic monomer (i) Unsaturated mono- or polycarboxylic acid, its acid anhydride or its salt (ii) Amide of unsaturated mono- or polycarboxylic acid (iii) Tertiary Nitrogen-containing monomer (iv) Sulfonic acid group-containing monomer Among these, preferred are unsaturated carboxylic acid esters, vinyl esters, and tertiary nitrogen-containing monomers. The molar ratio of the other vinyl monomer and the silyl compound having a polymerizable double bond is usually 1:0.01 to 1:100,
Preferably it is 1:0.05 to 1:50. If the molar ratio of the silyl compound having a polymerizable double bond to other vinyl monomers is less than 0.01, the hardness of the coating film after curing of the curable composition will not increase;
If it exceeds 100, the coating film becomes brittle. The reaction conditions for copolymerization (solvent, catalyst, temperature, etc.) may be the same as those described in Japanese Patent Application No. 108349/1982. In addition, the vinyl resin having a carbon-carbon double bond used in the case of (ii) is a vinyl resin having an average molecular weight of 300 to 50,000 that is mainly composed of a single or copolymer of other vinyl monomers in (i). Resin is suitable. By radical copolymerizing a portion (for example, 50 mol% or less, preferably 10 to 40 mol%) of allyl acrylate, allyl methacrylate, etc. during the production of single or copolymers of these vinyl monomers, vinyl-based resins can be produced. It becomes possible to introduce a carbon-carbon double bond in order to carry out the next hydrosilylation reaction. Further, if necessary, a chain transfer agent such as n-dodecylmercaptan may be added to adjust the molecular weight. A solvent may or may not be used during this reaction, but if used, a non-reactive solvent such as an ether,
Hydrocarbons, acetate esters, and ketones are preferred. Hydrosilane compounds used in the following hydrosilylation reaction include halogenated silanes (trichlorosilane, methyldichlorosilane, dimethyldichlorosilane, etc.), alkoxysilanes (trimethoxysilane, triethoxysilane, methyldimethoxysilane, methyldiethoxysilane, etc.) ), acetoxysilanes (triacetoxysilane, methyldiacetoxysilane, etc.), and aminoxysilanes (triaminoxysilane, methyldiaminoxysilane, etc.). The molar ratio of the carbon-carbon double bond in the vinyl resin to the hydrosilane compound is usually 1:0.5 to 1:
1.5, preferably 1:0.8 to 1:1.2. If the molar ratio of the hydrosilane compound to the carbon-carbon double bond is less than 0.5, the number of silyl groups introduced into the vinyl resin will be small, slowing down the curing of the resulting resin and reducing the physical properties (especially hardness) of the curable composition. If it exceeds 1.5, it will simply be recovered as unreacted hydrosilane and will be wasted. The reaction conditions for the hydrosilylation reaction are a temperature of 50°C.
~150°C is suitable. A solvent may or may not be used, but if it is used, the same solvent as used in the polymerization reaction (i) can be used. Details of the vinyl resin having a carbon-carbon double bond, reaction conditions, etc. are described in JP-A-54-123192. The average molecular weight of the vinyl resin (B) in the present invention is usually 500 to 50,000, preferably 800 to 30,000. The content of silyl groups in the resin is usually 0.1-20% by weight. The composition of the present invention contains (A) and (B). The weight ratio of (A) and (B) is usually 1:0.01 to 1:
100, preferably 1:0.1 to 1:10, particularly preferably 1:0.15 to 1:2. If (B) is less than 0.01, the physical properties and drying rate, which are the characteristics of the composition of the present invention, will not be improved much. Moreover, when (B) is more than 100, the drying speed is high, but a brittle coating film is produced. (A) and (B) can be mixed by preparing (A) and (B) in advance and then mixing (A) and (B), or by reacting B in (A). Any method is possible, such as reacting (A) in , (B). A curing accelerator may be used in the composition of the present invention if necessary. Examples of curing accelerators include titanates, amines, organotin compounds, acidic compounds, etc., such as alkyl titanates, metal salts of carboxylic acids such as tin octylate, dibutyltin dilaurate, dibutyltin maleate, dibutylamine-2-hexoate, etc. Amine salts and others JP-A-58-19361
Examples include the curing catalyst described in Japanese Patent Publication No. The amount of curing accelerator added is usually 0.001 to 20% by weight based on the resin content. The composition of the present invention may contain a solvent if necessary. These solvents include aromatic hydrocarbons (toluene, xylene, ethylbenzene, etc.), aliphatic hydrocarbons (hexane, heptane, cyclohexane, etc.), aliphatic ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, dibutyl ketone, cyclohexanone, etc.), and fatty acids. Examples include group ethers (dioxane, tetrahydrofuran, etc.), halogenated hydrocarbons (carbon tetrachloride, ethylene dichloride, etc.), and mixtures of two or more of these. Preferred are toluene, xylene, methyl ethyl ketone, methyl isobutyl ketone and ethylene dichloride, singly or in mixtures of two or more thereof. When making a composition containing a solvent, the solvent may be added to (A) or (B) to make the composition, but if (A) or (B) is manufactured in the presence of a solvent, the solvent must be removed. Instead, it may be included in the composition as it is. Compositions containing solvents are preferred for applications such as paints. The compositions of the present invention can be mixed with various fillers, pigments, etc. Various fillers and pigments can be used, such as various silicas, calcium carbonate, magnesium carbonate, titanium oxide, iron oxide, and glass fiber. Pigments described in JP-A-58-19361 can also be used. In addition, currently paint,
It can be blended with various resins used in coating agents, such as lacquer paints, acrylic paints, urethane paints, alkyd paints, melamine paints, epoxy paints, etc. in an appropriate formulation. It is possible to improve physical properties such as hardness, adhesion, and water resistance of these paints and coating agents. The composition of the present invention can contain various inorganic substances (iron, tinplate,
galvanized iron, aluminum, galvanized steel sheets, glass, roof tiles, slate, etc.) and organic materials (wood, paper, cellophane,
It can be applied to base materials such as plastics, organic paints, etc. Application methods include conventional methods such as brushing, spraying, and the like. The composition of the present invention can be used at room temperature to relatively low temperature (80℃
(below) can be cured by moisture. The tack-free time of the composition is usually 10 minutes to 3 hours. The composition of the present invention cures in the atmosphere to provide a coating film with high tensile strength and hardness, and has excellent physical properties of the coating film. Also, the coating film dries quickly (short curing time and short tack-free time). It also has good adhesion to inorganic materials such as glass and aluminum. The composition of the present invention shows a synergistic effect by containing (A) and (B), for example, the curing time is shorter than when (B) is used alone, and the physical properties of the coating film such as tensile strength are improved by (A).
Better than either alone. The composition of the present invention is useful as a paint, a coating agent, etc., and is also useful not only for the above-mentioned purposes, but also as a sealing agent, adhesive, casting material, etc. The present invention will be further explained below with reference to Production Examples, Examples, and Comparative Examples, but the present invention is not limited thereto. Production Example 1 0.2 mol of hexamethylene diisocyanate and 0.1 g of dibutyltin dilaurate were mixed with 60 ml of methyl isobutyl ketone, and the mixture was heated to 80 to 90°C.
Polycaprolactone polyol (MW2000)
0.1 mol was added in portions over 1 hour and reacted at the same temperature for 4 hours to obtain an NCO-terminated urethane prepolymer.
0.05 mol of dimethylaminoethanol and 0.15 mol of γ-mercaptopropyltrimethoxysilane were added and reacted at 90 to 100°C for 4 hours. Molecular weight approx.
2800 blocked urethane prepolymer (A) was obtained. Furthermore, vinyl polymerization was carried out in the same manner as in Production Example 1 using 0.15 mol of styrene, 0.15 mol of methyl methacrylate, 0.05 mol of γ-methacryloxypropylmethyldimethoxysilane, and 0.5 g of azobisisobutyronitrile to obtain urethane prepolymer (A). A mixture (composition of the present invention) with vinyl resin (B) was obtained. Production example 2 Isophorone diisocyanate in 60ml of xylene
0.2 mol and 0.05 g of dibutyltin dilaurate were mixed, and the temperature was raised to 80 to 90°C. Add 0.13mol of polypropylene glycol (MW400) dropwise over 1 hour.
The reaction was carried out at the same temperature for 4 hours to obtain an NCO-terminated urethane polymer. Furthermore, 0.03 mol of a 2-mol ethylene oxide adduct of methanol and 0.11 mol of γ-aminopropyltrimethoxysilane were added and reacted at the same temperature for 4 hours. A portion of this solution was sampled and the solvent was removed under reduced pressure to obtain a blocked urethane prepolymer (A) with a molecular weight of about 1200. The NCO content was 0. Production Example 3 A mixed solution of 0.3 mol of n-butyl methacrylate, 0.05 mol of γ-methacryloxypropyltrimethoxysilane and 0.5 g of azobisisobutyronitrile was added dropwise to 60 ml of xylene at 100 to 110°C over 30 minutes, and then heated to the same temperature. The mixture was allowed to react for 3 hours. Further, 0.1 g of asobisisobutyronitrile was added and the mixture was reacted for 2 hours to obtain a vinyl resin (B) having a hydrolyzable silyl group in the side chain. Looking at the infrared absorption spectrum of the product, it was confirmed that the absorption at 1648 m ^-1 had disappeared. Production example 4 Isophorone diisocyanate in 60ml of xylene
0.2 mol and 0.05 g of dibutyltin dilaurate were mixed, and the temperature was raised to 80 to 90°C. 0.08 mol of polypropylene glycol (MW400) and 0.05 mol of trimethylolpropane were added dropwise over 1 hour.
A time reaction was performed to obtain an NCO-terminated urethane prepolymer. Furthermore, 0.09 mol of γ-aminopropyltrimethoxysilane was added and the mixture was reacted at the same temperature for 4 hours. A urethane prepolymer capped with an average of more than two (2.39) silane coupling agents per polymer molecule was obtained. Example 1, Comparative Examples 1 to 3 Curable compositions of the present invention (Example 1 and Comparative Examples 1 to 3) were prepared by blending as shown in Table 1. 2 parts of dibutyltin dilaurate was added to 100 parts of each composition and applied to an aluminum plate, and the film forming ability and physical properties were measured. The results are shown in Table-1.

[Table] Production example 5 Isophorone diisocyanate in 60ml of xylene
0.2 mol and 0.05 g of dibutyltin dilaurate were mixed, and the temperature was raised to 80 to 90°C. 0.13 mol of holica prolactone polyol (MW500) was added dropwise over 1 hour and reacted at the same temperature for 4 hours to obtain an NCO-terminated urethane prepolymer. Furthermore, 0.03 mol of a 2-mol ethylene oxide adduct of methanol and 0.11 mol of γ-aminopropyltrimethoxysilane were added and reacted at the same temperature for 4 hours. Next, the temperature was raised to 100-110°C, and a mixed solution of 0.3 mol of n-butyl methacrylate, 0.05 mol of γ-methacryloxypropyltrimethoxysilane and 0.5 g of azobisisobutyronitrile was added dropwise over 30 minutes, and then at the same temperature. The reaction was allowed to proceed for 3 hours. Furthermore, 0.1 g of azobisisobutyronitrile was added and reacted for 2 hours. A mixture (composition of the present invention) of a urethane prepolymer (A) in which the NCO end was blocked and a vinyl resin (B) having a hydrolyzable silyl group in the side chain was obtained. Production example 6 Isophorone diisocyanate in 60ml of xylene
0.2 mol and 0.05 g of dibutyltin dilaurate were mixed, and the temperature was raised to 80 to 90°C. 0.08 mol of polycaprolactone polyol (MW500) and 0.05 mol of trimethylolpropane were added dropwise over 1 hour and reacted at the same temperature for 4 hours to obtain an NCO-terminated urethane prepolymer. Furthermore, 0.09 mol of γ-aminopropyltrimethoxysilane was added and the mixture was reacted at the same temperature for 4 hours. Average of 2 or more per polymer molecule (2.39
A urethane prepolymer capped with a silane coupling agent was obtained. Examples 2 to 4 Curable compositions of the present invention (Examples 2 to 4) were prepared by blending as shown in Table 2. 2 parts of dibutyltin dilaurate was added to 100 parts of each composition and applied to an aluminum plate, and the film forming ability and physical properties were measured. The results are shown in Table-2.

【table】

【table】

Claims (1)

[Scope of Claims] 1. A polyester polyol-based urethane prepolymer (A) whose terminal NCO groups are capped with an active hydrogen-containing silane coupling agent or this and other monofunctional active hydrogen-containing compound, and one NCO group per molecule of the polymer. A curable composition comprising the vinyl resin B containing a hydrolyzable silyl group as described above. 2 The silane coupling agent has a hydroxyl group,
The composition according to claim 1, which is a compound having an active hydrogen-containing group selected from the group consisting of an amino group and a mercapto group and a hydrolyzable silyl group selected from the group consisting of an alkoxysilyl group and a halosilyl group. 3. The composition according to claim 1 or 2, wherein the weight ratio of (A) and (B) is 1:0.01 to 1:100. 4. Any one of claims 1 to 3, wherein (A) is a polyester polyol-based urethane prepolymer whose terminal NCO groups are capped with an active hydrogen-containing silane coupling agent and a monofunctional active hydrogen-containing compound. Composition of. 5 Claims in which (B) is a copolymer of a silyl compound having a polymerizable double bond and another vinyl monomer or a reaction product of a vinyl resin having a carbon-carbon double bond and a hydrosilane compound Items 1 to 4
The composition according to any of paragraphs.