JP7045693B2 - Curable composition - Google Patents

Description

The present invention relates to a curable composition which is excellent in antifouling property, anti-adhesion property of a curing sheet and anti-foaming property, and also excellent in storage stability.

Since the curable composition containing an isocyanate group-containing resin is excellent in workability such as curability and adhesiveness and adhesiveness, it is widely used as a sealing material for construction and civil engineering, a waterproof material, an adhesive, a coating material, and the like. It is used. Curable compositions containing isocyanate group-containing resins can relatively freely adjust the cured rubber characteristics from low modulus to high modulus (high elongation to low elongation), but when designed in the low to medium modulus range, Tack (stickiness) may remain on the surface after curing.
In this case, dust and dirt are likely to adhere to the surface of the curable composition, and the surface is contaminated, causing design defects. In particular, when the curable composition is used outdoors or when the curable composition is in the process of being cured, the surface of the curable composition is highly tacky (sticky), so that a large amount of dust and dirt adheres to the curable composition. The surface of an object is contaminated. Therefore, as a method for preventing contamination due to stickiness on the surface of the curable composition, a curable composition containing an isocyanate group-containing urethane prepolymer and a silane compound has been proposed (for example, Patent Documents 1 and 2). ..

In addition, when using the curable composition, a curing tape or a curing sheet is attached to the peripheral member so that the curable composition does not adhere to a place other than the place where it is used, or after using the curable composition, When applying the topcoat paint to the surface or its peripheral members, a curing sheet may be attached to the surface of the curable composition even during the curing of the curable composition in order to shorten the construction period.
In this case, the curing sheet adheres to the surface of the curable composition mainly due to the tack (stickiness) on the surface of the curable composition, and when the curing sheet is peeled off after applying the topcoat paint, the surface layer portion of the curable composition May be pulled off by the drop clothes. If the surface layer of the curable composition is peeled off, that part must be repaired. Therefore, a specific silane compound or a partial hydrolyzate thereof is used for the purpose of not only preventing contamination due to stickiness on the surface of the curable composition after curing but also improving the adhesion prevention property of the curing sheet of the curable composition. A curable composition in which surface-treated calcium carbonate exhibiting a predetermined thermal loss is added to an isocyanate group-containing urethane prepolymer has been proposed (Patent Document 3).

Further, since the isocyanate group-containing resin reacts with water such as moisture to generate carbon dioxide gas, it may foam during curing and cause poor appearance or deterioration of physical properties of the cured product. Therefore, a curable composition has been proposed in which a latent curing agent such as an oxazolidine compound is blended with an isocyanate group-containing resin to prevent foaming during curing (Patent Document 4).

Japanese Unexamined Patent Publication No. 2008-201980 Japanese Unexamined Patent Publication No. 2009-07382 Japanese Unexamined Patent Publication No. 2017-082114 Japanese Unexamined Patent Publication No. 2011-066806

A curable composition containing an isocyanate group-containing resin and an oxazolidine compound has a rapid reaction with water such as moisture and is excellent in curability, but on the other hand, storage stability may be a problem. Specifically, if a product that has passed the summer (high temperature and high humidity period) since its production is used, the curable composition may partially react to increase the viscosity and deteriorate the workability during use. In addition, the curable composition cures quickly in summer, and after the curable composition is placed or applied, the excess curable composition remaining on the curing tape when the curing tape is peeled off is pulled while being semi-cured. In some cases, burrs may occur and the design may be impaired.
Therefore, it is possible to add a reaction inhibitor to the curable composition containing the isocyanate group-containing resin and the oxazolidine compound to improve the storage stability and adjust the curing, but then the curable composition is cast. Alternatively, after application, curing is slow and it is necessary to take a long curing time, resulting in poor work efficiency. As described above, since the storage stability and the curability of the curable composition containing the isocyanate group-containing resin and the oxazolidine compound are contradictory, it is difficult to improve the storage stability and the curability at the same time.

Further, when the curable composition is used for the working joint, a large displacement (movement) is received during the curing, and wrinkles are generated on the surface of the curable composition, which spoils the aesthetic appearance and causes a design defect. Further, if cracks or peeling occur in the curable composition, airtightness and watertightness cannot be ensured, which causes water leakage. Therefore, when a curable composition is used for a working joint, movement resistance is required.

That is, an object of the present invention is excellent in curability, stain prevention, curing sheet adhesion prevention, foaming prevention, storage stability, and a period of high temperature and humidity after production, which have been conventionally required. It is an object of the present invention to provide a curable composition which maintains good surface tack resistance and peeling property of a curing tape even after a lapse of time and, if necessary, also has a desired movement resistance.

As a result of diligent studies to solve the above problems, the present inventors have found that a curable composition containing an isocyanate group-containing resin, an oxazolidine compound, a bismuth compound, and a phosphoric acid ester compound has curability and stain resistance. It has been found that the curing sheet is excellent in adhesion prevention property and foaming prevention property, is also excellent in storage stability, and can be provided with good movement resistance as needed, and has completed the present invention.
That is, the present invention solves the above-mentioned problems by providing a curable composition having the aspects shown in the following (1) to (16).
(1) A curable composition containing an isocyanate group-containing resin, an oxazolidine compound, a bismuth compound, and a phosphoric acid ester compound.
(2) The curable composition of (1), wherein the bismuth compound is a salt of trivalent bismuth and an organic acid.
(3) The curable composition of (1) or (2), wherein the bismuth compound is tris (2-ethylhexanoic acid) bismuth (III).
(4) The curable composition according to any one of (1) to (3), wherein the phosphoric acid ester compound is an acidic phosphoric acid ester.
(5) The phosphate ester compound is ethyl acid phosphate, butyl acid phosphate, dibutylpyrophosphate, butoxyethyl acid phosphate, 2-ethylhexyl acid phosphate, alkyl (C12, C14, C16, C18) acid phosphate, isotridecyl acid phosphate. , The curable composition according to any one of (1) to (4), which is at least one phosphate ester compound selected from oleyl acid phosphate and tetracosyl acid phosphate.
(6) The curable composition according to any one of (1) to (5), wherein the blending amount of the bismuth compound is 0.005 to 5 parts by mass with respect to 100 parts by mass of the isocyanate group-containing resin.
(7) Curing of any one of (1) to (6), wherein the blending amount of the phosphoric acid ester compound is 0.01 to 5 parts by mass with respect to 100 parts by mass of the total amount of the isocyanate group-containing resin and the oxazolidine compound. Sex composition.
(8) The curable composition according to any one of (1) to (7), wherein the isocyanate group-containing resin has a branch density of 0.03 mmol / g or more.
(9) The curable composition according to any one of (1) to (8), wherein the isocyanate group-containing resin has a photoreactive unsaturated bond in the molecule.
(10) The curable composition according to any one of (1) to (9), further containing a surface-treated calcium carbonate having a heat loss of 50 to 150 mg / g.
(11) The curable composition according to any one of (1) to (10), further containing fine powdered silica.
(12) The curable composition of (11), wherein the fine powdered silica has 0.5 to 3 / nm ² silanol groups on its surface.
(13) The curable composition according to any one of (1) to (12), further containing a silane compound represented by the following general formula (1) and / or a partially hydrolyzed condensate of the silane compound.
R _4-m Si- (OR ¹ ) _m (1)
(In the formula (1), R represents a monovalent hydrocarbon group having 1 to 6 carbon atoms, and when there are a plurality of Rs, they may be the same or different. R ¹ is 1 having 1 or more carbon atoms. Although it is a valent hydrocarbon group, at least one of (OR ¹ ) is an alkoxy group having 2 to 6 carbon atoms. When there are a plurality of (OR ¹ ), they may be the same or different. Is an integer from 1 to 4.)
(14) Further, at least one selected from a curing accelerating catalyst, a plasticizer, a weather resistance stabilizer, a filler, a rocking denaturing agent, an adhesiveness improving agent, a storage stability improving agent (dehydrating agent), a colorant and an organic solvent. The curable composition according to any one of (1) to (13), which contains an additive of more than one species.
(15) The curable composition according to any one of (1) to (14), wherein the curable composition is a curable composition for construction or civil engineering.
(16) The curable composition according to any one of (1) to (15), wherein the curable composition is a sealing material composition, a waterproof material composition, an adhesive composition or a coating material composition.

The curable composition of the present invention is excellent in curability, antifouling property, anti-adhesion property of a curing sheet, and anti-foaming property, and is also excellent in storage stability. It exhibits good surface tack resistance and peeling tape, and can also provide good movement resistance as needed.

The curable composition of the present invention is characterized by containing an isocyanate group-containing resin, an oxazolidine compound, a bismuth compound, and a phosphoric acid ester compound. Hereinafter, each component will be described in detail.

The isocyanate group-containing resin is a resin having one or more isocyanate groups in the resin. The isocyanate group reacts with the active hydrogen-containing compound to form a urethane bond, a urea bond, or the like, and is crosslinked and cured. The isocyanate group-containing resin is simply "urethane prepolymer" including an isocyanate group-containing urethane prepolymer (hereinafter, an isocyanate group-containing urethane prepolymer and an isocyanate group-containing urethane prepolymer having a photoreactive unsaturated bond introduced later). In some cases,) can be preferably mentioned.

The isocyanate group-containing urethane prepolymer can be produced by reacting an organic isocyanate compound with an active hydrogen-containing compound all at once or sequentially so that an isocyanate group remains in the urethane prepolymer. The molar ratio (isocyanate group / active hydrogen) of the isocyanate group of the organic isocyanate compound to the active hydrogen of the active hydrogen-containing compound is preferably 1.2 to 10, and more preferably 1.2 to 5. When the molar ratio is less than 1.2, the viscosity of the urethane prepolymer becomes high, and the workability of the curable composition deteriorates. Further, when the molar ratio exceeds 10, the amount of carbon dioxide gas generated when the isocyanate group reacts with water increases, which causes foaming during curing.

The isocyanate group content of the isocyanate group-containing urethane prepolymer is preferably 0.3 to 15% by mass, and particularly preferably 0.5 to 5% by mass. When the isocyanate group content is less than 0.3% by mass, the viscosity of the urethane prepolymer becomes high and the workability of the curable composition deteriorates. When the isocyanate group content exceeds 15% by mass, the amount of carbon dioxide gas generated when the isocyanate group reacts with water increases, which causes foaming during curing.

The number average molecular weight of the isocyanate group-containing urethane prepolymer is preferably 1,500 or more, more preferably 1,500 to 20,000, further preferably 1,500 to 15,000, and particularly preferably 1,500 to 10,000. preferable. The number average molecular weight in the present invention is a polystyrene-equivalent value measured by gel permeation chromatography (GPC).

The branch density of the isocyanate group-containing urethane prepolymer is preferably 0.03 mmol / g or more, more preferably 0.03 to 0.1 mmol / g. When the branch density of the urethane prepolymer is less than 0.03 mmol / g, when the curing sheet is attached to the surface of the curable composition, the curing sheet adheres to the surface of the curable composition and is difficult to peel off. The branch density of the urethane prepolymer can be theoretically obtained by calculation from the raw material for producing the urethane prepolymer (content of the raw material having a branched structure).

As a method for producing the isocyanate group-containing urethane prepolymer, a conventionally known method can be used. Specifically, a method in which an organic isocyanate compound and an active hydrogen-containing compound are charged in a reaction vessel made of glass or stainless steel, a reaction catalyst or an organic solvent is used as necessary, and the reaction is carried out while stirring at 50 to 120 ° C. Can be mentioned. At this time, since the urethane prepolymer thickens when the isocyanate group reacts with water such as moisture, it is preferable to replace the inside of the container with nitrogen gas in advance or to carry out the reaction under a nitrogen gas stream.

Examples of the organic isocyanate compound include organic polyisocyanate. The organic polyisocyanate is a compound having two or more isocyanate groups in the compound, and specifically, a toluene polyisocyanate such as 2,4-toluene diisocyanate or 2,6-toluene diisocyanate, 4,4'-. Diphenylmethane polyisocyanate such as diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, 2,2'-diphenylmethane diisocyanate, 1,2-phenylenediocyanate, 1,3-phenylenediocyanate, 1,4-phenylenediocyanate, 2,4,6 -Phenylene polyisocyanate such as trimethylphenyl-1,3-diisocyanate, 2,4,6-triisopropylphenyl-1,3-diisocyanate, naphthalene polyisocyanate such as 1,4-naphthalenediocyanate, 1,5-naphthalenediocyanate, etc. Fragrances such as chlorophenylene-2,4-diisocyanate, 4,4'-diphenylether diisocyanate, 3,3'-dimethyldiphenylmethane-4,4'-diisocyanate, 3,3'-dimethoxydiphenyl-4,4'-diisocyanate Polyisocyanate can be mentioned. In addition, 1,6-hexamethylene diisocyanate, 1,5-pentamethylene diisocyanate, 1,4-tetramethylene diisocyanate, 2,2,4-trimethyl-1,6-hexamethylene diisocyanate, 2,4,4-trimethyl- Aromatic aliphatic polyisocyanates such as 1,6-hexamethylene diisocyanate, decamethylene diisocyanate, lysine diisocyanate, o-xylylene diisocyanate, m-xylylene diisocyanate, p-xylylene diisocyanate, 1,4- Examples thereof include alicyclic polyisocyanates such as cyclohexamethylene diisocyanate, isophorone diisocyanate, hydrogenated toluene diisocyanate, hydrogenated xylylene diisocyanate, and hydrogenated diphenylmethane diisocyanate. Further, polypeptide isocyanates such as polymethylene polyphenyl polyisocyanate and crude toluene diisocyanate can be mentioned. Further, modified isocyanates obtained by modifying these organic polyisocyanates and having one or more uretdione bond, isocyanurate bond, allophanate bond, burette bond, uretonimine bond, carbodiimide bond, urethane bond or urea bond can be mentioned. All of these can be used alone or in combination of two or more.

Of these, an aliphatic polyisocyanate, an aromatic aliphatic polyisocyanate, an alicyclic polyisocyanate, and a modified isocyanate obtained by modifying these organic polyisocyanates are preferable because the curable composition has excellent weather resistance.

Further, an organic monoisocyanate can be used together with the organic polyisocyanate. That is, a mixture of an organic polyisocyanate and an organic monoisocyanate can be used as the above-mentioned organic isocyanate compound. The organic monoisocyanate is a compound having one isocyanate group in the compound, and specifically, n-butyl monoisocyanate, n-hexyl monoisocyanate, n-hexadecyl monoisocyanate, n-octadecyl monoisocyanate, Examples thereof include p-isopropylphenylmonoisocyanate and p-benzyloxyphenylmonoisocyanate.

An active hydrogen-containing compound is a compound having one or more active hydrogens (groups) in the compound. Specific examples thereof include high molecular weight polyols, high molecular weight polyamines, low molecular weight polyols, low molecular weight amino alcohols, low molecular weight polyamines, high molecular weight monools, and low molecular weight monools. These can be used alone or in combination of two or more.

Examples of the polymer polyol include polyoxyalkylene-based polyols, polyester polyols, polycarbonate polyols, hydrocarbon-based polyols, poly (meth) acrylate-based polyols, and animal and plant-based polyols. Of these, polyoxyalkylene-based polyols and poly (meth) acrylate-based polyols are preferable. In the present invention, "(meth) acrylate" means "acrylate and / or methacrylate".

The number average molecular weight of the polymer polyol is preferably 1,000 to 30,000, more preferably 1,000 to 20,000.

Examples of the polyoxyalkylene-based polyol include polyoxyalkylene-based triols and polyoxyalkylene-based diols.

In the present invention, the "system" of the polyoxyalkylene-based triol and the polyoxyalkylene-based diol is 50% by mass or more, more 80% by mass or more, particularly 90% by mass or more of the portion of the molecule excluding the hydroxyl group. If it is composed of polyoxyalkylene, it means that the remaining portion may be modified with ester, urethane, polycarbonate, polyamide, poly (meth) acrylate, polyolefin or the like. Most preferably, 95% by mass or more of the molecule excluding the hydroxyl group is composed of polyoxyalkylene.

The polyoxyalkylene-based triol and the polyoxyalkylene-based diol can be obtained by ring-opening addition polymerization of an alkylene oxide with an initiator in the presence of a polymerization catalyst. The total degree of unsaturation of the polyoxyalkylene-based triol and the polyoxyalkylene-based diol is preferably 0.1 meq / g or less, more preferably 0.07 meq / g or less, and particularly preferably 0.04 meq / g or less.

Examples of the polymerization catalyst include alkali metal compound catalysts such as sodium-based catalysts and potassium-based catalysts, cationic polymerization catalysts, composite metal cyanation complex catalysts such as zinc hexacyanocobaltate glyme complex and diglyme complex, and phosphazene compound catalysts. Of these, alkali metal compound catalysts and composite metal cyanide complex catalysts are preferable.

As the initiator, a compound having 2 to 3 active hydrogen (groups) (hydroxyl groups or amino groups capable of reacting with an alkylene oxide) in the molecule is used. A small amount of a compound having 4 active hydrogens (groups) in the molecule can also be used in combination with these.

As an initiator for producing a polyoxyalkylene-based triol, a compound having 3 active hydrogens (groups) is mainly used. Specific examples of the compound having 3 active hydrogens include trihydric alcohols such as glycerin and trimethylolpropane.

As an initiator for producing a polyoxyalkylene-based diol, a compound having 2 active hydrogens (groups) is mainly used. Specific examples of the compound having 2 active hydrogens include dihydric alcohols such as ethylene glycol, propylene glycol, 1,4-butanediol, diethylene glycol, dipropylene glycol, bisphenol A, and bisphenol F.

Examples of the alkylene oxide include ethylene oxide, propylene oxide, 1,2-epoxybutane, and 2,3-epoxybutane. Of these, the combined use of propylene oxide, ethylene oxide, propylene oxide and ethylene oxide is preferable, and the combined use of propylene oxide, propylene oxide and ethylene oxide is more preferable.

As the polyoxyalkylene triol, polyoxypropylene triol, polyoxyethylene triol, and polyoxyethylene propylene triol are preferable, and polyoxypropylene triol and polyoxyethylene propylene triol are more preferable. The number average molecular weight of the polyoxyalkylene triol is preferably 1,000 to 30,000, more preferably 1,000 to 20,000.

In the present invention, the "oxyethylene propylene" contains an oxyethylene group (-CH ₂ CH ₂ O-) and an oxypropylene group (-CH (CH ₃ ) CH ₂ O-) in the molecule.

As the polyoxyalkylene-based diol, polyoxypropylene diol, polyoxyethylene diol, and polyoxyethylene propylene diol are preferable, and polyoxypropylene diol and polyoxyethylene propylene diol are more preferable. The number average molecular weight of the polyoxyalkylene-based diol is preferably 1,000 to 30,000, more preferably 1,000 to 20,000.

Examples of the polyester polyol include succinic acid, adipic acid, sebacic acid, azelaic acid, terephthalic acid, isophthalic acid, orthophthalic acid, hexahydroterephthalic acid, hexahydroisophthalic acid, hexahydroorthophthalic acid, naphthalenedicarboxylic acid, trimellitic acid and the like. Polycarboxylic acid, one or more of these anhydrides or carboxylic acids including alkyl esters such as methyl ester and ethyl ester, ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2 -Butandiol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, neopentyl glycol, 1,8 -Low molecular weight polyols such as octanediol, 1,9-nonanediol, diethylene glycol, dipropylene glycol, 1,4-cyclohexanedimethanol, ethylene oxide or propylene oxide adduct of bisphenol A, trimethylolpropane, glycerin, pentaerythritol, etc. Examples thereof include polyester polyols obtained by reacting with one or more of the above. Further, in addition to these carboxylic acids and low molecular weight polyols, one of low molecular weight polyamines such as butylene diamine, hexamethylenediamine, xylylenediamine and isophorone diamine, and low molecular weight amino alcohols such as monoethanolamine and diethanolamine. A polyesteramide polyol obtained by reacting with the above can also be mentioned.

As the polycarbonate polyol, a dehydroxylation reaction between the low molecular weight polyols used for synthesizing the above-mentioned polyester polyol and phosgene, or a transesterification reaction between the above-mentioned low molecular weight polyols and diethylene carbonate, dimethyl carbonate, diethyl carbonate, and diphenyl carbonate. The ones that can be obtained from.

As the poly (meth) acrylate-based polyol, a (meth) acrylate monomer containing a hydroxyl group such as hydroxyethyl (meth) acrylate and another (meth) acrylic acid alkyl ester monomer are used as a radical polymerization initiator. Examples thereof include those copolymerized in the presence or absence.

Examples of the hydrocarbon-based polyol include polyolefin polyols such as polybutadiene polyols and polyisoprene polyols; polyalkylene polyols such as hydrogenated polybutadiene polyols and hydrogenated polyisoprene polyols; halogenated polyalkylene polyols such as chlorinated polypropylene polyols and chlorinated polyethylene polyols. Can be mentioned.

Examples of animal and plant-based polyols include castor oil-based polyols and silk fibroin.

Any of the above-mentioned polymer polyols can be used alone or in combination of two or more.

Further, the polymer monool can be used in combination with the above-mentioned polymer polyol. The number average molecular weight of the polymer monool is preferably 1,000 to 30,000, more preferably 1,000 to 20,000.

When a polymer polyol and a polymer monool are used in combination, the combination thereof is preferably a polymer triol and a polymer diol and a polymer monool, or a polymer triol and a polymer monool.

As the polymer monool, polyoxyalkylene-based monool is preferable.

In the present invention, the "system" of the polyoxyalkylene-based monool is composed of 50% by mass or more, further 80% by mass or more, particularly 90% by mass or more of the portion excluding the hydroxyl group in the molecule. If so, it means that the remaining portion may be modified with an ester, urethane, polycarbonate, polyamide, poly (meth) acrylate, polyolefin or the like. Most preferably, 95% by mass or more of the molecule excluding the hydroxyl group is composed of polyoxyalkylene.

The polyoxyalkylene-based monool is obtained by ring-opening addition polymerization of an alkylene oxide with an initiator in the presence of a polymerization catalyst. The total degree of unsaturation of the polyoxyalkylene-based monool is preferably 0.1 meq / g or less, more preferably 0.07 meq / g or less, and particularly preferably 0.04 meq / g or less.

Examples of the polymerization catalyst include alkali metal compound catalysts such as sodium-based catalysts and potassium-based catalysts, cationic polymerization catalysts, composite metal cyanation complex catalysts such as zinc hexacyanocobaltate glyme complex and diglyme complex, and phosphazene compound catalysts. Of these, alkali metal compound catalysts and composite metal cyanide complex catalysts are preferable.

As an initiator for producing a polyoxyalkylene-based monool, a compound having 1 active hydrogen (group) is mainly used. Specific examples of the compound having 1 active hydrogen (group) include monohydric alcohols such as methanol, ethanol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, and tert-butyl alcohol; phenol, Monohydric phenols such as nonylphenol; secondary amines such as dimethylamine and diethylamine can be mentioned.

When the polymer monool is used in combination, the content of the polymer monool in the isocyanate group-containing urethane prepolymer is preferably 5 to 30% by mass with respect to the total amount of the urethane prepolymer. When the content of the polymer monool in the urethane prepolymer is within the above range, the curable composition has excellent durability (for example, the durability of JIS A 5758). In particular, as the branching density of the urethane prepolymer is increased, the physical properties of the curable composition after curing tend to be high modulus and low elongation, and the durability tends to decrease. By setting the oar content in the above range, the cured composition of the curable composition has excellent durability even if the branching density of the urethane prepolymer is increased.

The isocyanate group-containing urethane prepolymer can also introduce a photoreactive unsaturated bond into the urethane prepolymer for the purpose of imparting weather resistance. The urethane prepolymer having a photoreactive unsaturated bond acts as a curing component in the curable composition of the present invention, and at the same time, imparts good adhesion to the adherend surface and excellent weather resistance to the cured composition. It is a thing. The above-mentioned photoreactive unsaturated bond is an unsaturated bond that causes a chemical change such as polymerization in a relatively short time when exposed to light. Specific examples thereof include unsaturated bonds derived from a vinyl group, a vinylene group, and a (meth) acryloyl group. In the present invention, the "(meth) acryloyl group" means "acryloyl group and / or methacryloyl group".

The isocyanate group of the isocyanate group-containing urethane prepolymer into which a photoreactive unsaturated bond has been introduced reacts with the active hydrogen-containing compound and is cross-linked and cured. In addition, the photoreactive unsaturated bond of the isocyanate group-containing urethane prepolymer into which a photoreactive unsaturated bond has been introduced undergoes a polymerization reaction when exposed to light, and a cured film having excellent weather resistance is formed on the surface of the curable composition. To form. It is considered that this cured film imparts excellent weather resistance to the curable composition. As the photoreactive unsaturated bond, an unsaturated bond derived from a (meth) acryloyl group is preferable because it has a high effect of imparting weather resistance.

Examples of the method for introducing a photoreactive unsaturated bond into an isocyanate group-containing urethane prepolymer include the following methods.
(B) Organic isocyanate compounds, high molecular weight active hydrogen-containing compounds (number average molecular weight of 1,000 or more), and low-molecular-weight active hydrogen-containing compounds (number) having active hydrogen and photoreactive unsaturated bonds in the molecule. (Average molecular weight less than 1,000) is reacted with the total amount of active hydrogen under the condition of excess isocyanate group;
(B) An organic isocyanate compound and a polymer (number average molecular weight of 1,000 or more) active hydrogen-containing compound having an active hydrogen and a photoreactive unsaturated bond in the molecule (for example, a mono (meth) of polyoxyalkylene triol. ) A method obtained by reacting acrylate, an alkylene oxide adduct of (meth) acrylic acid, a polybutadiene polyol) with the total amount of active hydrogen under the condition of excess isocyanate group; and (c) an organic isocyanate compound and an intramolecular method. A low molecular weight (number average molecular weight less than 1,000) active hydrogen-containing compound (for example, (meth) acryloyl isocyanate) having a photoreactive unsaturated bond and an isocyanate group, and a polymer (number average molecular weight 1,000 or more). ) With the active hydrogen-containing compound in the condition of excess isocyanate group with respect to the total amount of active hydrogen;
The method (a) described above is preferable in terms of availability of raw materials and ease of reaction. In the present invention, "(meth) acrylic acid" means "acrylic acid and / or methacrylic acid".

In the reaction of introducing a photoreactive unsaturated bond into an isocyanate group-containing urethane prepolymer, the raw materials may be charged and reacted in a batch, or the raw materials may be charged and reacted in sequence. The molar ratio (isocyanate group / active hydrogen) of the isocyanate group of the organic isocyanate compound to the active hydrogen of the active hydrogen-containing compound (including the compound having an active hydrogen and a photoreactive unsaturated bond) is 1.2 to 10. Is preferable, and 1.2 to 5 is more preferable. The isocyanate group content in the isocyanate group-containing urethane prepolymer into which a photoreactive unsaturated bond has been introduced is preferably 0.3 to 15% by mass, more preferably 0.5 to 5% by mass. When the isocyanate group content is less than 0.3% by mass, the molecular weight becomes too large, the viscosity increases, and the workability deteriorates. In addition, since the number of cross-linking points in the urethane prepolymer is reduced, sufficient adhesiveness cannot be obtained. When the isocyanate group content exceeds 15% by mass, the amount of carbon dioxide gas generated when the isocyanate group reacts with water increases, which causes foaming during curing.

The concentration of the photoreactive unsaturated bond in the isocyanate group-containing urethane prepolymer into which the photoreactive unsaturated bond has been introduced is preferably 0.01 mmol / g or more, more preferably 0.03 to 1 mmol / g, and particularly preferably 0.03 to 1 mmol / g. It is preferably 0.05 to 0.5 mmol / g.

The above-mentioned active hydrogen-containing compound (small molecule and high molecular weight) having an active hydrogen and a photoreactive unsaturated bond has an active hydrogen (group) such as a hydroxyl group, an amino group, a carboxyl group, and a vinyl group in the compound. , Vinylene group, (meth) acryloyl group and other compounds having both photoreactive unsaturated bonds. A compound having a hydroxyl group and a (meth) acryloyl group in the compound is preferable in terms of ease of reaction and high effect of imparting weather resistance. Further, the molecular weight of the compound having an active hydrogen (group) and a photoreactive unsaturated bond is preferably one having a number average molecular weight of less than 1,000 in terms of easy reaction.

Examples of the active hydrogen-containing compound having a hydroxyl group and a (meth) acryloyl group include 2-hydroxyethyl (meth) acrylate, which is a monoester of an alkylene glycol such as ethylene glycol, propylene glycol, butylene glycol and (meth) acrylic acid. , 2-Hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 4-hydroxypentyl (meth) acrylate, hydroxyneopentyl (meth) acrylate, 6-hydroxyhexyl ( Monohydroxymono (meth) acrylates such as meth) acrylates, hydroxyheptyl (meth) acrylates and hydroxyoctyl (meth) acrylates, trifunctional or higher alkylene polyols such as glycerin, trimethylolpropane and pentaerythritol, and (meth) acrylic acid. Monohydrokipoly (meth) acrylates such as glycerin di (meth) acrylate, trimethyl proprani (meth) acrylate, pentaerythritol tri (meth) acrylate, and glycerin mono, which are monoesters or polyesters such as diesters and triesters. Polyhydrokimono (meth) acrylates such as (meth) acrylate, trimethylolpropane mono (meth) acrylate, pentaerythritol mono (meth) acrylate, and polyhydrochipoly (meth) acrylates such as pentaerythritol di (meth) acrylate. Can be mentioned. In addition to these, monohydroxymono (meth) such as diethylene glycol, dipropylene glycol, polyoxyethylene polyol, polyoxypropylene polyol, and polyols obtained by adding alkylene oxides such as ethylene oxide, propylene oxide, and butylene oxide to bisphenol A and bisphenol F. ) Acrylate, polyhydroxymono (meth) acrylate, polyhydroxypoly (meth) acrylate, (meth) acrylic acid, hydroxyethyl (meth) acrylate and other hydroxyalkyl (meth) acrylate active hydrogen, ethylene oxide, propylene oxide , Butylene oxide and other compounds to which an alkylene oxide is added and having a hydroxyl group, and a caprolactone modified product of hydroxyethyl acrylate having a hydroxyl group and the like can also be mentioned. These can be used alone or in combination of two or more. Of these, monohydroxypoly (meth) acrylates and dihydroxypoly (meth) acrylates are preferable in that the viscosity of the urethane prepolymer can be kept low and the effect of imparting weather resistance can be enhanced.

The oxazolidine compound will be described. The oxazolidine compound is a compound having one or more, preferably 1 to 6, particularly preferably 2 to 3 oxazolidine rings, which are heterocycles of saturated 5-membered rings containing an oxygen atom and a nitrogen atom. The oxazolidine compound reacts with water such as moisture and is hydrolyzed, and the oxazolidine ring produces (regenerates) a secondary amino group and an alcoholic hydroxyl group, thereby functioning as a latent curing agent for the isocyanate group-containing resin. be. When the isocyanate group of the isocyanate group-containing resin reacts with water such as moisture, it forms a urea bond and is cured. At this time, carbon dioxide gas is also generated, and bubbles due to carbon dioxide gas are generated in the cured product to deteriorate the appearance. Problems such as breakage of the cured product and deterioration of adhesiveness may occur. On the other hand, when a curable composition using an isocyanate group-containing resin and an oxazolidine compound is reacted with water, the water reacts preferentially with the oxazolidine compound, and the oxazolidine ring of the oxazolidine compound is alcoholic with the secondary amino group. Generates a hydroxyl group (active hydrogen group). Next, since the generated active hydrogen group (particularly the secondary amino group) reacts preferentially with the isocyanate group, the generation of carbon dioxide gas due to the reaction between water and the isocyanate group is suppressed, and the curable composition is foamed during curing. Can be prevented.

Further, when an aliphatic polyisocyanate or an alicyclic polyisocyanate is used as the organic polyisocyanate used for the isocyanate group-containing resin, the curing of the curable composition may be delayed. When the isocyanate group-containing resin and the oxazolidine compound are used in combination, the curing of the curable composition can be accelerated.

Further, the oxazolidine compound has an effect of preventing the generation of cracks on the surface of the curable composition in the curable composition containing an isocyanate group-containing resin and a silane compound and / or a partially hydrolyzed condensate of the silane compound described later. Have. Cracks on the surface of the curable composition cause the silane compound and / or the partially hydrolyzed condensate of the silane compound to bleed onto the surface of the curable composition and hydrolyze as the curable composition cures. Since the formed cured film is hard, if the cured film is displaced, it is presumed that the displacement cannot be followed and cracks occur. When the oxazolidine compound is blended, the cured film of the silane compound and / or the partially hydrolyzed condensate of the silane compound is made flexible by the action of the secondary amino group generated by the hydrolysis of the oxazolidine compound and the alcoholic hydroxyl group. It is presumed that this will prevent the occurrence of cracks.

Examples of the oxazolidine compound include a urethane bond-containing oxazolidine compound, an ester group-containing oxazolidine compound, an oxazolidine silyl ether compound, and a carbonate group-containing oxazolidine compound. These oxazolidine compounds are obtained by reacting the hydroxyl group of a compound having a hydroxyl group and an oxazolidin ring with the isocyanate group of an organic polyisocyanate or the carboxyl group of an organic carboxylic acid compound. Of these oxazolidine compounds, urethane bond-containing oxazolidine compounds are preferable because they are easy to produce.

Specific examples of the compound having a hydroxyl group and an oxazolidine ring include N-hydroxyalkyloxazolidine obtained by a dehydration condensation reaction between a secondary amino group of an alkanolamine and a carbonyl group of a ketone compound or an aldehyde compound. As a method for producing the compound having the hydroxyl group and the oxazolidine ring, 1 mol or more, preferably 1 to 1.5 mol, more preferably 1 mol, more preferably 1 mol, of the carbonyl group of the aldehyde compound or the ketone compound with respect to 1 mol of the secondary amino group of alkanolamine. Is used, and a method of performing a dehydration condensation reaction while heating and refluxing in an organic solvent such as toluene or xylene to remove by-produced water can be mentioned. Excess aldehyde compounds and ketone compounds can be removed by distillation.

Examples of the alkanolamine include diethanolamine, dipropanolamine, and N- (2-hydroxyethyl) -N- (2-hydroxypropyl) amine. Examples of the ketone compound include acetone, diethyl ketone, isopropyl ketone, methyl ethyl ketone, methyl propyl ketone, methyl isopropyl ketone, methyl butyl ketone, methyl isobutyl ketone, methyl-tert-butyl ketone, diisobutyl ketone, cyclopentanone and cyclohexanone. Examples of the aldehyde compound include acetaldehyde, propionaldehyde, n-butyl aldehyde, isobutyl aldehyde, barrel aldehyde, isobarrel aldehyde, 2-methylbutyl aldehyde, n-hexyl aldehyde, 2-methylpentyl aldehyde, n-octyl aldehyde, 3,5. , 5-Trimethylhexylaldehyde and other aliphatic aldehyde compounds; examples thereof include aromatic aldehyde compounds such as benzaldehyde, methylbenzaldehyde, trimethylbenzaldehyde, ethylbenzaldehyde, isopropylbenzaldehyde, isobutylbenzaldehyde, methoxybenzaldehyde, dimethoxybenzaldehyde and trimethoxybenzaldehyde. All of these can be used alone or in combination of two or more.

Of these, diethanolamine is preferable as the alkanolamine, and the ketone compound or the aldehyde compound is preferable because it is easy to produce a compound having a hydroxyl group and an oxazolidine ring and is excellent in foaming prevention property when the curable composition is cured. Of these, aldehyde compounds are preferable, and isobutyl aldehyde, 2-methylpentyl aldehyde, and benz aldehyde are more preferable.

Compounds having a hydroxyl group and an oxazolidine ring include 2-isopropyl-3- (2-hydroxyethyl) oxazolidine, 2- (1-methylbutyl) -3- (2-hydroxyethyl) oxazolidine, and 2-phenyl-3- (2). -Hydroxyethyl) Oxazolidine can be mentioned.

As the urethane bond-containing oxazolidine compound, the isocyanate group of the organic polyisocyanate and the hydroxyl group and the hydroxyl group of the compound having an oxazolidine ring have an isocyanate group / hydroxyl group molar ratio of 0.9 to 1.2, preferably 0.95 to 1. Preferable examples thereof include those obtained by reacting at a temperature of 50 to 120 ° C. by using the compound so as to be 05, using an organic solvent or a reaction catalyst as necessary.

Examples of the organic polyisocyanate used for producing the urethane bond-containing oxazolidine compound include the same organic polyisocyanates used for producing the urethane prepolymer described above. Of these, aromatic aliphatic polyisocyanates and aliphatic polyisocyanates are preferable, and xylylene diisocyanate and hexamethylene diisocyanate are particularly preferable.

The ester group-containing oxazolidine compound can be obtained by reacting the above-mentioned compound having a hydroxyl group and an oxazolidin ring with a lower alkyl ester of a dicarboxylic acid or a polycarboxylic acid.

The oxazolidinesilyl ether compound includes the above-mentioned compounds having a hydroxyl group and an oxazolidin ring, trimethoxysilane, tetramethoxysilane, triethoxysilane, dimethoxydimethylsilane, vinyltrimethoxysilane, vinyltriethoxysilane, and 3-glycidoxypropyltri. It is obtained by a dealcohol reaction with an alkoxysilane such as methoxysilane and 3-glycidoxypropyltriethoxysilane.

The carbonate group-containing oxazolidine compound can be obtained by reacting the above-mentioned compound having a hydroxyl group and an oxazolidine ring with a carbonate such as diallyl carbonate using a polyhydric alcohol such as diethylene glycol or glycerin.

Each of these oxazolidine compounds can be used alone or in combination of two or more.

The oxazolidine compound preferably does not have an active hydrogen-containing functional group such as an amino group or a hydroxyl group that reacts with the isocyanate group of the isocyanate group-containing resin, or an isocyanate group. This is to prevent an increase in the viscosity of the isocyanate group-containing resin and a decrease in the foaming prevention performance of the oxazolidine compound. However, in the production of the above-mentioned urethane bond-containing oxazolidine compound, a small amount of active hydrogen-containing functional group or isocyanate group may remain in the molecule depending on the selection of the molar ratio. In this case, in order to achieve the object of the present invention. It can be considered that it does not have. The "small amount" means that the amount of the active hydrogen-containing functional group or isocyanate group remaining in the molecule is preferably 0.05 mmol or less, more preferably 0.02 mmol or less per 1 g of the oxazolidine compound.

The blending amount of the oxazolidine compound is 0.1 to 1 mol of the active hydrogen of the secondary amino group produced (regenerated) by hydrolysis of the oxazolidine compound with respect to 1 mol of the isocyanate group of the isocyanate group-containing resin. It is preferably 0.3 to 1 mol, and particularly preferably 0.5 to 1 mol. If the amount of active hydrogen of the secondary amino group produced (regenerated) by hydrolysis of the oxazolidine compound is less than 0.1 mol, the prevention of foaming is insufficient, which is not preferable.

The bismuth compound will be described. The bismuth compound accelerates the curing of the curable composition of the present invention. Specifically, it accelerates the reaction between the isocyanate group-containing resin and the active hydrogen-containing compound. As the active hydrogen-containing compound in this reaction, water such as moisture, a secondary amino group or an alcoholic hydroxyl group generated by hydrolysis (opening) of the oxazolidine ring of the oxazolidine compound, and the curable composition of the present invention are used as two liquids. Examples thereof include a curing agent (hydroxyl group, amino group, thiol group) when used as a type reaction curable composition. In addition, the bismuth compound can be used as a reaction catalyst when synthesizing the above-mentioned urethane prepolymer and oxazolidine compound.

The bismuth compound can be added at the time of synthesizing the isocyanate group-containing urethane prepolymer and / or at the time of synthesizing the oxazolidine compound and / or at the time of preparing the curable composition. If an amount effective in accelerating the curability of the curable composition is blended at the time of synthesizing the isocyanate group-containing urethane prepolymer and / or at the time of synthesizing the oxazolidine compound, the curable composition is prepared. The curing of the curable composition can be accelerated even if it is not blended at the time of preparation.

Examples of the bismuth compound include salts of bismuth and an organic acid, and among them, salts of trivalent bismuth and an organic acid are preferable. Examples of salts of trivalent bismuth and organic acid include bismuth triheptate (III), bismuth tris (2-ethylhexanoic acid) bismuth (III), tris (neodecanic acid) bismuth (III), and bismuth trilaurate (III). , Bismuth tristearate (III). All of these can be used alone or in combination of two or more.

The blending amount of the bismuth compound is preferably 0.005 to 5 parts by mass, and particularly preferably 0.005 to 2 parts by mass with respect to 100 parts by mass of the isocyanate group-containing resin.

The phosphoric acid ester compound will be described. The phosphoric acid ester compound promotes hydrolysis (ring opening) of the oxazolidine ring of the oxazolidine compound in the curable composition of the present invention. By promoting the hydrolysis of the oxazolidine ring, the generated secondary amino group and alcoholic hydroxyl group (active hydrogen group) react with the isocyanate group of the isocyanate group-containing resin, and the curing of the curable composition is promoted.

In a curable composition containing an isocyanate group-containing resin and an oxazolidine compound, a curing accelerator that accelerates the reaction between the isocyanate group-containing resin and the active hydrogen (group) -containing compound, and an opening that promotes hydrolysis of the oxazolidine ring of the oxazolidine compound. Although the use of a ring accelerator accelerates the curing of the curable composition, it is difficult to adjust the curing of the curable composition when an accelerator having a different curing accelerating action (mechanism) is used. In many cases, the properties, storage stability, and peeling ability of the curing tape deteriorate.
By using the bismuth compound and the phosphoric acid ester compound in combination, a curable composition having excellent anti-staining property, anti-surface tack property, storage stability, and peeling property of curing tape can be obtained while ensuring curing promoting property.

Examples of the phosphoric acid ester compound include a normal phosphoric acid ester compound and a phosphite ester compound. Of these, a positive phosphoric acid ester compound is preferable. All of these can be used alone or in combination of two or more.

Examples of the positive phosphate compound include a trialkyl ester compound of positive phosphoric acid, a dialkyl ester compound of positive phosphoric acid, and a monoalkyl ester compound of positive phosphoric acid.

Examples of the trialkyl ester compound of positive phosphoric acid include trimethyl phosphate, triethyl phosphate, triphenyl phosphate, tricresyl phosphate, tricylylrel phosphate, cresyldiphenyl phosphate and cresyldi 2,6-xylenyl phosphate.
Examples of the monoalkyl ester compound and the dialkyl ester compound (acidic phosphoric acid ester compound) of positive phosphate include ethyl acid phosphate, butyl acid phosphate, dibutyl pyrophosphate, butoxyethyl acid phosphate, 2-ethylhexyl acid phosphate, and alkyl (C12, C14). , C16, C18) Acid phosphate, isotridecyl acid phosphate, oleyl acid phosphate, tetracosyl acid phosphate, ethylene glycol acid phosphate, 2-hydroxyethyl methacrylate acid phosphate.
Examples of the monoalkyl ester compound include monoethyl phosphate, monobutyl phosphate, monobutoxyethyl phosphate, monon-octyl phosphate, mono2-ethylhexyl phosphate, monolauryl phosphate and mono (2-hydroxyethyl methacrylate) phosphate.
Examples of the dialkyl ester compound include diethyl phosphate, dibutyl phosphate, dibutyl pyrophosphate, dibutoxyethyl phosphate, din-octyl phosphate, bis (2-ethylhexyl) phosphate, diisotridecyl phosphate and diolyl phosphate.
Any of these positive phosphoric acid ester compounds can be used alone or in combination of two or more.

Examples of the phosphite compound include phosphorous acid triester compounds such as triethyl phosphite, triphenyl phosphite, trisnonylphenyl phosphite, tridecylphosphite, diphenylmono (2-ethylhexyl) phosphite, and diphenylmonodecylphosphite. , Phosphorous acid diester compounds such as dilauryl hydrogen phosphite, diolayl hydrogen phosphite, diphenylhydrogen phosphite and the like.
Each of these phosphite ester compounds can be used alone or in combination of two or more.

The blending amount of the phosphoric acid ester compound is preferably 0.01 to 5 parts by mass, particularly preferably 0.01 to 3 parts by mass with respect to 100 parts by mass of the total amount of the isocyanate group-containing resin and the oxazolidine compound.

The curable composition of the present invention can further contain surface-treated calcium carbonate. Surface-treated calcium carbonate imparts rocking denaturation to the curable composition, and is used for the purpose of preventing sagging and slump when the curable composition is used on a vertical surface or an inclined surface, and the curable composition is bead coated. , Used for the purpose of maintaining the applied shape when applied with a shaving iron or the like. Further, the surface-treated calcium carbonate can be obtained as a curable composition by using surface-treated calcium carbonate having a heat loss of 200 to 500 ° C. of 50 to 150 mg / g at a heating rate of 15 ° C./min in combination with an isocyanate group-containing resin. It has excellent anti-adhesion to the curing sheet. Further, when used in combination with a silane compound and / or a partially hydrolyzed condensate of a silane compound described later, the curable composition is further excellent in preventing adhesion to the curing sheet. To the extent that the effect of preventing adhesion of the curing sheet can be ensured, surface-treated calcium carbonate having a heat loss of 50 to 150 mg / g and surface-treated calcium carbonate other than surface-treated calcium carbonate having a heat loss of 50 to 150 mg / g are used in combination. be able to.

Examples of the surface-treated calcium carbonate include fatty acid surface-treated calcium carbonate. Examples of the fatty acid surface-treated calcium carbonate include those obtained by treating the surface of heavy calcium carbonate, light calcium carbonate, and colloidal calcium carbonate with fatty acids such as fatty acids, fatty acid alkyl esters, fatty acid metal salts, and fatty acid organic salts. Of these, calcium carbonate surface-treated with a fatty acid or a fatty acid metal salt is preferable because it has a high effect of imparting shake denaturation. All of these can be used alone or in combination of two or more.

Fatty acids include lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, beef stearate, palm kernel fatty acid, partially cured palm fatty acid, extremely hardened palm fatty acid, palm fatty acid, partially hardened palm fatty acid, extremely hardened palm fatty acid, Examples thereof include palm fatty acid, palm stearic acid, beef fatty acid, partially hardened beef fatty acid, extremely hardened beef fat fatty acid, soybean fatty acid, partially hardened soybean fatty acid, extremely hardened soybean fatty acid, naphthenic acid, avietinic acid, and neoavietic acid. Examples of the metal salt include sodium salt, potassium salt, calcium salt and aluminum salt, and examples of the organic salt include ammonium salt.

Commercially available products of fatty acid surface-treated calcium carbonate include Maruo Calcium's Sealets 200, Calfine 200, Calfine 200M, Calfine 500, Calfine N-40, Calfine N-350; White glossy flower CCR, white glossy flower CCR-S, white glossy flower CCR-B, VIGOT-10, VIGOT-15, Viscolite-SV, Viscolite-OS, Viscolite EL-20; NCC # 3010, NCC # 1010 of Nitto Powder Industry Co., Ltd. can be mentioned. ..

The particle size of the surface-treated calcium carbonate is preferably 0.01 to 1 μm, more preferably 0.01 to 0.3 μm. The particle size of the surface-treated calcium carbonate can be determined as the primary particle size measured by an electron microscope. The BET specific surface area of the surface-treated calcium carbonate is preferably 5 to 200 m ² / g, more preferably 10 to 60 m ² / g. If the particle size is less than 0.01 μm or the BET specific surface area is more than 200 m ² / g, the viscosity of the obtained curable composition becomes high and the workability deteriorates, which is not preferable. If the particle size exceeds 1 μm or the BET specific surface area is less than 5 m ² / g, the effect of imparting sway denaturation decreases, which is not preferable.

The heat loss of the surface-treated calcium carbonate is preferably 50 to 150 mg / g, more preferably 50 to 120 mg / g, because the curable composition has good property of preventing adhesion to the curing sheet. The heat loss of surface-treated calcium carbonate can be determined by thermogravimetric analysis (TG). Specifically, for example, it can be obtained by the following measurement method.
[Measuring method]
10 mg of surface-treated calcium carbonate is weighed in a platinum sample pan having a diameter of 5 mm, and the temperature is raised from room temperature to 510 ° C. at a rate of 15 ° C./min using a thermogravimetric analyzer (TG8120, manufactured by Rigaku Co., Ltd.). At this time, the weight reduced in the range of 200 to 500 ° C. is measured, and the heat loss (mg / g) per 1 g of the surface-treated calcium carbonate is determined.

The blending amount of the surface-treated calcium carbonate is preferably 1 to 200 parts by mass, more preferably 5 to 150 parts by mass with respect to 100 parts by mass of the isocyanate group-containing resin.

The curable composition of the present invention can further contain fine powdered silica. The fine powder silica imparts rocking modification to the curable composition in the same manner as the above-mentioned surface-treated calcium carbonate, and has the purpose of preventing the generation of sagging and slump when the curable composition is used on a vertical surface or an inclined surface. , The curable composition is used for the purpose of maintaining the coating shape when it is applied with a bead application, a silica-mesh iron, or the like. Further, by using fine powdered silica, when the curable composition is displaced (movement) during curing, the generation of wrinkles on the surface thereof is suppressed.

Examples of the fine powder silica include hydrophilic silica and hydrophobic silica. Hydrophilic silica is preferable because it has a high effect of imparting rocking denaturation and is excellent in movement resistance of the curable composition. All of these can be used alone or in combination of two.

Examples of the hydrophilic silica include natural silica obtained by finely pulverizing quartz and silica sand, and synthetic silica such as dry silica and wet silica. Dry silica is obtained by burning a silane compound such as silicon tetrachloride in an oxyhydrogen flame, and is sometimes called fumed silica. In addition, wet silica includes precipitation method silica in which an aqueous solution of sodium silicate is neutralized with an acid to precipitate silica in the aqueous solution, and is sometimes called white carbon.

Hydrophobic silica is obtained by reacting a silanol group of hydrophilic silica with a silicone oil, a silane coupling agent, hexamethyldisilazane, chlorosilanes, etc. to make the surface hydrophobic.

The BET specific surface area of the fine powder silica is preferably 10 to 500 m ² / g, more preferably 50 to 500 m ² / g. The average primary particle size of the fine powder silica is preferably 1 to 100 nm.

The fine powder silica preferably has a silanol group (Si—OH group) of 0.5 to 3 elements / nm ² on its surface.

The blending amount of the fine powder silica is preferably 0.1 to 10% by mass, more preferably 0.1 to 5% by mass, based on the entire curable composition.

The curable composition of the present invention may further contain a silane compound and / or a partially hydrolyzed condensate of the silane compound. The silane compound and / or the partially hydrolyzed condensate of the silane compound can be combined with an isocyanate group-containing resin and surface-treated calcium carbonate having a heat loss of 50 to 150 mg / g to prevent contamination and adhere to a curing sheet in the curable composition. It imparts a preventive effect. This is because when the curable composition is cured by water such as moisture, the silane compound and / or the partially hydrolyzed condensate of the silane compound migrates (bleeds) to the surface of the curable composition from the middle of curing, resulting in moisture. It is considered that this is due to reducing the stickiness of the surface of the curable composition by forming a hydrophilic film on the surface of the curable composition by being hydrolyzed by water such as and condensing while dealcoholizing. By reducing the stickiness of the surface of the curable composition, it becomes difficult for dust and dirt to adhere to the surface of the curable composition, and the antifouling property is improved. Further, even if dust or dust adheres to the surface of the curable composition, the dust or dust can be removed relatively easily by spraying running water such as rain or a shower or compressed air.

The silane compound is a compound represented by the following general formula (1), and is a silane compound having at least one alkoxy group other than a methoxy group in the molecule.
R _4-m Si (OR ¹ ) _m (1)
(In the formula (1), R represents a monovalent hydrocarbon group having 1 to 6 carbon atoms, and when there are a plurality of Rs, they may be the same or different. R ¹ is 1 having 1 or more carbon atoms. Although it is a valent hydrocarbon group, at least one of (OR ¹ ) is an alkoxy group having 2 to 6 carbon atoms. When there are a plurality of (OR ¹ ), they may be the same or different. Is an integer from 1 to 4.)

The R is a monovalent group having 1 to 6 carbon atoms and having no reactive functional group such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a heptyl group, a hexyl group and a phenyl group. Examples include hydrocarbon groups.

The (OR ¹ ) is an alkoxy group, and when m is 1, (OR ¹ ) is an alkoxy group other than the methoxy group. When m is 2, 3 or 4, at least one of (OR ¹ ) is an alkoxy group other than a methoxy group.

Examples of the alkoxy group other than the methoxy group include an alkoxy group having 2 or more carbon atoms such as an ethoxy group, a propoxy group, an isopropoxy group, a butoxy group, an isobutoxy group, a pentoxy group, a hexoxy group and a phenoxy group.

Examples of the silane compound include tetraethoxysilane, tetrapropoxysilane, tetraisopropoxysilane, tetrabutoxysilane, methyltriethoxysilane, methyltripropoxysilane, methyltriisopropoxysilane, methyltributoxysilane, and dimethoxydiethoxysilane. Will be. All of these can be used alone or in combination of two or more.

The partially hydrolyzed condensate of a silane compound is a multimer obtained by partially hydrolyzing the alkoxy group of the above-mentioned silane compound in the presence or absence of a solvent and condensing the silane compound linearly or three-dimensionally. .. The partially hydrolyzed condensate of the silane compound is preferably a 2 to 20-mer from the viewpoint of transferability (bleeding) to the surface of the curable composition and film formation property after transfer to the surface of the curable composition.

Specific examples of the partially hydrolyzed condensate of the silane compound include ethyl silicate 40 (average pentamer), ethyl silicate 48 (average tetramer), and Corcote Co., Ltd., which contain a partially hydrolyzed condensate of tetraethoxysilane. EMS-485 (average 10-mer) containing a partially hydrolyzed condensate of diethoxydimethoxysilane, manufactured by Corcote; MKC containing a condensate of a partially hydrolyzed condensate of tetramethoxysilane partially butoxydated with butanol. Hydrolyzed MS58B15, MS58B30, MS51, MS56, M57, MS56S, manufactured by Mitsubishi Chemical Corporation; All of these can be used alone or in combination of two or more.

The blending amount of the silane compound and / or the partially hydrolyzed condensate of the silane compound is preferably 0.01 to 20 parts by mass, more preferably 0.1 to 10 parts by mass with respect to 100 parts by mass of the isocyanate group-containing resin. If the blending amount is less than 0.01 parts by mass, the effect of preventing contamination of the surface of the curable composition and the effect of preventing adhesion of the curing sheet are small. When the blending amount exceeds 20 parts by mass, the amount of alcohol generated by hydrolyzing the silane compound and / or the partially hydrolyzed condensate of the silane compound increases, and the generated alcohol reacts with the isocyanate group of the isocyanate group-containing resin. May cause curing failure.

The curable composition of the present invention may contain various additives in addition to the above-mentioned components, if necessary, as long as the object of the present invention is not impaired. Additives are added to the curable composition and used to improve various performances such as viscosity adjustment, curing acceleration, and adhesiveness of the curable composition. Specific examples thereof include a curing accelerating catalyst, a plasticizer, a weather resistance stabilizer, a filler, a rocking denaturing agent, an adhesiveness improving agent, a storage stability improving agent (dehydrating agent), a colorant and an organic solvent. All of these can be used alone or in combination of two or more.

The curing acceleration catalyst is used to promote cross-linking and curing of the isocyanate group-containing resin by reacting with water such as moisture. It is also used to promote the reaction between the secondary amino group or alcoholic hydroxyl group generated from the oxazolidine compound and the isocyanate group of the isocyanate group-containing resin. Further, it is used to promote the reaction between the curing agent (hydroxyl group, amino group, thiol group) and the isocyanate group of the isocyanate group-containing resin when the curable composition of the present invention is used as a two-component reaction curable composition. do. The curing acceleration catalyst referred to here is something other than the above-mentioned bismuth compound and phosphoric acid ester compound. The curing acceleration catalyst can also be used as a reaction catalyst in the production of the above-mentioned urethane prepolymer and / or oxazolidine compound. When used as a reaction catalyst during the production of the urethane prepolymer and / or the oxazolidine compound, the reaction catalyst remaining in the urethane prepolymer and / or the oxazolidine compound acts as a curing acceleration catalyst for the curable composition. There is also.

Specific examples of the curing acceleration catalyst include metal-based catalysts and amine-based catalysts.

Examples of the metal-based catalyst include a salt of a metal and an organic acid, a salt of an organic metal and an organic acid, and a metal chelate compound. Examples of the salt of the metal and the organic acid include salts of various metals such as tin, zirconium, zinc and manganese with organic acids such as octyl acid, neodecanoic acid, stearic acid and naphthenic acid. Specific examples thereof include tin octylate, tin naphthenate, and zirconium octylate. Salts of organic metals and organic acids include dibutyltin dioctate, dibutyltin dilaurate, dibutyltin diacetate, dibutyltin dimaleate, dibutyltin distearate, dioctyltin dilaurate, dioctyltin diversatete, and reaction of dibutyltin diverseate with phthalates. Things can be mentioned. Examples of the metal chelate compound include dibutyltin bis (acetylacetonet), EXCESTAR C-501 manufactured by Asahi Glass Co., Ltd., zirconium tetrakis (acetylacetonate), titanium tetrakis (acetylacetonate), and aluminum tris (acetylacetone). Nart), aluminum tris (ethylacetacetate), acetylacetone cobalt, acetylacetone iron, acetylacetone copper, acetylacetone magnesium, acetylacetone nickel, acetylacetone zinc, acetylacetone manganese.

Examples of the amine-based catalyst include tertiary amines. Examples of tertiary amines include triethylamine, tributylamine, triethylenediamine, hexamethylenetetramine, 1,8-diazabicyclo [5,4,0] undecene-7 (DBU), 1,4-diazabicyclo [2,2,2]. Examples include octane (DABCO) and salts of these tertiary amines and organic carboxylic acids.

All of these curing acceleration catalysts can be used alone or in combination of two or more.

The amount of the curing acceleration catalyst to be blended is preferably 0.005 to 5 parts by mass, particularly 0.005 to 2 parts by mass with respect to 100 parts by mass of the isocyanate group-containing resin.

In addition to the above-mentioned metal catalyst and amine catalyst, an organic carboxylic acid catalyst and a reaction product of p-toluenesulfonyl isocyanate and water can be used. The reaction product of p-toluenesulfonyl isocyanate and water, which is an organic carboxylic acid catalyst, promotes the hydrolysis of the oxazolidine ring of the oxazolidine compound when the oxazolidine compound is added to the curable composition. By promoting the hydrolysis of the oxazolidine ring, the generated secondary amino group and alcoholic hydroxyl group (active hydrogen group) react with the isocyanate group of the isocyanate group-containing resin, and the curing of the curable composition is promoted.

Examples of the organic carboxylic acid-based catalyst include formic acid, acetic acid, propionic acid, caproic acid, oxalic acid, succinic acid, adipic acid, 2-ethylhexanoic acid (octyl acid), octenoic acid, lauric acid, oleic acid, stearic acid and the like. Examples thereof include α, β-unsaturated carboxylic acids such as aliphatic carboxylic acids, maleic acids and acrylic acids, and aromatic carboxylic acids such as phthalic acids, benzoic acids and salicylic acids.

As the reaction product of p-toluenesulfonyl isocyanate and water, one obtained by reacting p-toluenesulfonyl isocyanate with water in advance before blending with the curable composition of the present invention, p-toluenesulfonyl isocyanate is cured. Examples thereof include those in which water is added and reacted while being blended in the sex composition, and those in which water is reacted with water present in the curable composition.

The plasticizer is used for the purpose of lowering the viscosity of the curable composition to improve workability and adjusting the physical characteristics of the rubber after curing of the curable composition. Specifically, phthalates such as dioctyl phthalate, diisononyl phthalate, dibutyl phthalate, and butyl benzyl phthalate; aliphatic carboxylic acid esters such as dioctyl adipate, diisodecyl succinate, dibutyl sebacate, and butyl oleate. Low molecular weight plasticizers such as; polyoxyalkylene-based triols, polyoxyalkylene-based diols, and polyoxyalkylene-based monools similar to those that can be used for the synthesis of urethane prepolymers described above are urethaneized, etherified or esterified. A high molecular weight plasticizer having a number average molecular weight of 1,000 or more; a plasticizer having a number average molecular weight of 1,000 or more that does not react with isocyanate groups such as polystyrenes such as poly-α-methylstyrene and polystyrene. Be done. All of these can be used alone or in combination of two or more.

The amount of the plasticizer to be blended is preferably 1 to 200 parts by mass, more preferably 2 to 50 parts by mass with respect to 100 parts by mass of the isocyanate group-containing resin.

The weathering stabilizer is used for the purpose of preventing oxidation, photodegradation and thermal deterioration of the curable composition to further improve the weathering resistance and heat resistance. Examples of the weather resistance stabilizer include a hindered amine-based light stabilizer, a hindered phenol-based antioxidant, and an ultraviolet absorber. All of these weather resistant stabilizers can be used alone or in combination of two or more.

Examples of hindered amine-based photostabilizers include bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate and bisdecanediate (2,2,6,6-tetramethyl-1 (octyloxy) -4. -Piperidyl) ester, bis (1,2,2,6,6-pentamethyl-4-piperidyl) [[3,5-bis (1,1-dimethylethyl) -4-hydroxyphenyl] methyl] butyl malonate, Methyl 1,2,2,6,6-pentamethyl-4-piperidyl sebacate, bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, 1- [2- [3- (3,3) 5-Di-tert-butyl-4-hydroxyphenyl) propionyloxy] ethyl] -4- [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionyloxy] -2,2,6 Low molecular weight compounds with a molecular weight of less than 1,000, such as 6-tetramethylpiperidine, 4-benzoyloxy-2,2,6,6-tetramethylpiperidine; dimethyl 1- (2-hydroxyethyl) succinate-4- (2-hydroxyethyl) -4- Hydroxy-2,2,6,6-tetramethylpiperidine polycondensate, poly [{6- (1,1,3,3-tetramethylbutyl) amino-1,3,5-triazine-2,4-diyl } {(2,2,6,6-tetramethyl-4-piperidyl) imino} hexamethylene {(2,2,6,6-tetramethyl-4-piperidyl) imino}], N, N'-bis ( 3-Aminopropyl) Ethylenediamine-2,4-bis [N-butyl-N- (1,2,2,6,6-pentamethyl-4-piperidyl) amino] -6-chloro-1,3,5-triazine In addition to the condensate, compounds having a molecular weight of 1,000 or more, such as Adecaster LA-63P and LA-68LD manufactured by ADEKA, can be mentioned.

Examples of hindered phenolic antioxidants include pentaerythritol-tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] and octadecyl-3- (3,5-di-tert-butyl). -4-Hydroxyphenyl) propionate, N, N'-hexane-1,6-diylbis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propioamide], benzenepropanoic acid 3,5-bis Examples thereof include (1,1-dimethylethyl) -4-hydroxy C7-C9 side chain alkyl ester and 2,4-dimethyl-6- (1-methylpentadecyl) phenol.

Examples of the UV absorber include benzotriazole-based UV absorbers such as 2- (3,5-di-tert-butyl-2-hydroxyphenyl) -5-chlorobenzotriazole; 2- (4,6-diphenyl-1, 3,5-Triazine-2-yl) -5-[(hexyl) oxy] -triazine-based UV absorbers such as phenol; benzophenone-based UV absorbers such as octabenzone; 2,4-di-tert-butylphenyl-3 , 5-Di-tert-butyl-4-hydroxybenzoate and the like are benzoate-based UV absorbers.

Of these, hindered amine-based photostabilizers, hindered phenol-based antioxidants, and mixtures thereof are preferable because they are highly effective in improving weather resistance. The blending amount of the weather resistance stabilizer is preferably 0.01 to 30 parts by mass, more preferably 0.1 to 10 parts by mass with respect to 100 parts by mass of the isocyanate group-containing resin.

The filler is used as a bulking agent for the curable composition and for the purpose of reinforcing the physical properties of the cured product. Examples include inorganic fillers and organic fillers. Inorganic fillers include heavy calcium carbonate, light calcium carbonate, colloidal calcium carbonate, mica, kaolin, zeolite, graphite, diatomaceous clay, white clay, clay, talc, anhydrous silicic acid, quartz, aluminum powder, zinc powder, hydroxylated. Inorganic powder-like fillers such as calcium, magnesium carbonate, and alumina; examples thereof include inorganic fibrous fillers such as glass fibers and carbon fibers. Examples of the organic filler include organic powder fillers such as wood flour, walnut flour, rice husk flour, pulp powder, rubber powder, and thermoplastic or thermosetting resin powder. Further, flame-retardant fillers such as magnesium hydroxide and aluminum hydroxide can be mentioned. All of these can be used alone or in combination of two or more.

The blending amount of the filler is preferably 1 to 500 parts by mass, more preferably 10 to 300 parts by mass, and particularly preferably 10 to 200 parts by mass with respect to 100 parts by mass of the isocyanate group-containing resin.

The rocking denaturing agent imparts rocking denaturation to the curable composition in the same manner as the above-mentioned surface-treated calcium carbonate and fine powder silica, and when the curable composition is used on a vertical surface or an inclined surface, sagging and slump are generated. It is used for the purpose of preventing Examples of the shaking denaturing agent include an inorganic shaking denaturing agent and an organic shaking denaturing agent. In addition to the above-mentioned surface-treated calcium carbonate and fine powdered silica, sepiolite (magnesium silicate), apatargite (magnesium aluminum silicate), and wallastite (calcium silicate) are examples of the inorganic rocking agent. Can be mentioned. Examples of the organic denaturing agent include fatty acid amide. All of these can be used alone or in combination of two or more.

The adhesiveness improver is used for the purpose of improving the adhesiveness of the curable composition. Specific examples thereof include various coupling agents such as silane-based, aluminum-based, and zircoaluminate-based, or partial hydrolysis condensates thereof. Of these, a silane-based coupling agent or a partially hydrolyzed condensate thereof is preferable because it has excellent adhesiveness.

Examples of the silane coupling agent include vinyltrimethoxysilane, vinylmethyldimethoxysilane, 3- (meth) acryloxypropyltrimethoxysilane, 3- (meth) acryloxypropylmethyldimethoxysilane, and 3-mercaptopropyltrimethoxysilane. 3-Aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, N- (2-aminoethyl) Examples thereof include compounds having an alkoxysilyl group of -3-aminopropylmethyldiethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane and the like and having a molecular weight of 500 or less. Further, a compound having a molecular weight of 200 to 3,000, which is a partially hydrolyzed condensate of one or more of these silane-based coupling agents, can be mentioned. All of these can be used alone or in combination of two or more.

The storage stability improver (dehydrating agent) is used for the purpose of improving the storage stability of the curable composition. Specific examples thereof include vinyltrimethoxysilane and calcium oxide which react with water present in the curable composition and act as a dehydrating agent. All of these can be used alone or in combination of two or more.

The colorant is used for the purpose of coloring the curable composition and imparting design to the cured product. Specific examples thereof include inorganic pigments such as titanium oxide and iron oxide, organic pigments such as copper phthalocyanine, and carbon black. All of these can be used alone or in combination of two or more.

The organic solvent is used for the purpose of lowering the viscosity of the curable composition and improving the extrudability and workability such as casting and coating. The organic solvent can be used without particular limitation as long as it has good compatibility with other components in the curable composition and does not react with other components. Specifically, a carbonate solvent such as dimethyl carbonate, a ketone solvent such as acetone or methyl ethyl ketone, an ester solvent such as ethyl acetate or butyl acetate, an aliphatic solvent such as n-hexane, and an alicyclic solvent such as cyclohexane. Examples thereof include solvents, aromatic solvents such as toluene and xylene, and organic solvents such as petroleum distillate solvents such as mineral spirit and industrial gasoline. All of these can be used alone or in combination of two or more. These organic solvents may be used in the synthesis of urethane prepolymers or in the preparation of curable compositions.

Since the curable composition of the present invention is cured by reacting with water such as moisture in the air, it can be used as a one-component moisture-curable composition. It can also be used as a two-component reaction-curable composition using the curable composition of the present invention as a main component and an active hydrogen-containing compound such as a polyamine or a polyol as a curing agent. It is preferable to use it as a one-component moisture-curable composition because it does not require the trouble of mixing the main agent and the curing agent, does not cause curing defects due to mixing mistakes or insufficient mixing, and has excellent workability.

When the curable composition of the present invention is used, the materials (members) to be constructed include mortar, concrete, ALC (Autoclaved Lightweight Concrete), glass, marble, mikage stone, siding, tile, roof tile, and brick. Inorganic materials such as iron, copper, stainless steel, galvanium steel plate, totan, aluminum, titanium and other metal materials, acrylic resin, polyester resin, vinyl chloride, ABS (Acrylonitrile-Butadiene-Styrene copolymer), FRP (Fiber Reinforced Plastic), etc. Materials made of synthetic resin; wood materials such as wood and plywood can be mentioned.

The method for producing the curable composition of the present invention is not particularly limited, but specifically, an isocyanate group-containing resin, an oxazolidine compound, a bismuth compound, a phosphoric acid ester compound, and, if necessary, a heat loss of 50 to 50 or more. 150 mg / g surface treatment Calcium carbonate, fine powder silica, silane compound and / or partially hydrolyzed condensate of silane compound, additive is made of glass, stainless steel, iron, etc. and mixed with a stirrer that can block water such as moisture. It can be manufactured by charging it in a container, stirring it under a dry air or dry nitrogen stream, and mixing it. Further, as a method for producing the curable composition, a batch method or a continuous method can be used.

Since the curable composition of the present invention is thickened and cured by water such as moisture, it is preferable to pack it in a container capable of blocking water such as moisture and store it in a sealed manner. The container is not particularly limited as long as it can block water such as humidity. Specific examples thereof include metal and resin pail cans, aluminum and resin bags, and paper and resin cartridges.

Examples of the present invention are shown below, but the present invention is not construed as being limited to the examples.

[Synthesis Example 1] (Synthesis of Isocyanate Group-Containing Urethane Prepolymer PU-1)
581.8 g of polyoxypropylene diol (number average molecular weight 3,300, Excelol 3021, manufactured by Asahi Glass Co., Ltd.) while flowing nitrogen gas through a stirrer, thermometer, nitrogen seal tube, and reaction vessel with heating / cooling device, polyoxy 160.0 g of propylene triol (number average molecular weight 4,000, Triol-MN-4000, manufactured by Mitsui Chemicals, Inc.), 100.0 g of polyoxypropylene monool (number average molecular weight 3080, Preminol 1003, manufactured by Asahi Glass Co., Ltd.), penta Add 30.0 g of erythritol triacrylate (molecular weight 298), and stir with isophorone diisocyanate (molecular weight 222.3, manufactured by Ebonic Japan) 128.2 g, tris (2-ethylhexanoic acid) bismuth (III) (Neostan U-600). , Nitto Kasei Co., Ltd.) was charged, heated and reacted at 75 to 85 ° C. for 4 hours. The reaction was terminated when the isocyanate group content became the theoretical value (2.3% by mass) or less, and the isocyanate group-containing urethane prepolymer PU-1 was synthesized. The branch density (theoretical value) of the isocyanate group-containing urethane prepolymer PU-1 is 0.04 mmol / g, and the content of the acryloyl group (theoretical value) is 0.3 mmol / g.
[Synthesis Example 2] (Synthesis of Isocyanate Group-Containing Urethane Prepolymer PU-2)
581.8 g of polyoxypropylene diol (number average molecular weight 3,300, Excelol 3021, manufactured by Asahi Glass Co., Ltd.) while flowing nitrogen gas through a stirrer, thermometer, nitrogen seal tube, and reaction vessel with heating / cooling device, polyoxy 160.0 g of propylene triol (number average molecular weight 4,000, Triol-MN-4000, manufactured by Mitsui Chemicals, Inc.), 100.0 g of polyoxypropylene monool (number average molecular weight 3080, Preminol 1003, manufactured by Asahi Glass Co., Ltd.), penta Add 30.0 g of erythritol triacrylate (molecular weight 298) and add isophoron diisocyanate (molecular weight 222.3, manufactured by Ebonic Japan) 128.2 g and dibutyltin dilaurate (Neostan U-100, manufactured by Nitto Kasei) while stirring. 2 g was charged, heated, and reacted at 75 to 85 ° C. for 4 hours. The reaction was terminated when the isocyanate group content became the theoretical value (2.3% by mass) or less, and the isocyanate group-containing urethane prepolymer PU-2 was synthesized. The branch density (theoretical value) of the isocyanate group-containing urethane prepolymer PU-2 is 0.04 mmol / g, and the content of the acryloyl group (theoretical value) is 0.3 mmol / g.
[Synthesis Example 3] (Synthesis of Urethane Bond-Containing Oxazolidine Compound O-1)
In a stirrer, thermometer, nitrogen seal tube, ester tube, and reaction vessel with heating / cooling device, 435.0 g of diethanolamine (molecular weight 105) and 183.0 g of toluene were charged, and isobutyraldehyde (molecular weight 72.1) was added while stirring. 328.0 g was charged, heated while flowing nitrogen gas, and the reflux dehydration reaction was continued at 110 to 150 ° C., and by-produced water (74.5 g) was taken out of the system. After completion of the reaction, the mixture was further heated under reduced pressure (50 to 70 hPa) to remove unreacted isobutyraldehyde with toluene to obtain N-hydroxyethyl-2-isopropyloxazolidine, which is an intermediate reaction product.
Next, 348.0 g of hexamethylene diisocyanate (molecular weight 168) was further added to 659.0 g of the obtained N-hydroxyethyl-2-isopropyloxazolidine, and the mixture was heated at 80 ° C. for 8 hours, and the measured NCO content by titration was 0. The reaction end point was set at 0% by mass, and a urethane bond-containing oxazolidine compound O-1 having two oxazolidine rings in the molecule was obtained. The urethane bond-containing oxazolidine compound O-1 was a liquid at room temperature.

[Example 1]
100 g of the isocyanate group-containing urethane prepolymer PU-1 obtained in Synthesis Example 1 was charged into a kneading container equipped with a stirrer, a heater, a cooling device, and a nitrogen seal tube while nitrogen gas was flowed, and dried at 100 to 110 ° C. in advance while stirring. 20 g of heavy calcium carbonate (Whiten B, manufactured by Shiraishi Calcium Co., Ltd.) dried in the machine to reduce the water content to 0.05% by mass or less, fatty acid surface-treated calcium carbonate (Calfine N-40, heat loss 95) 1.0 mg / g (manufactured by Maruo Calcium) was charged, 100 g of titanium oxide, and 10 g of diisononyl phthalate (DINP) were charged and mixed until the contents became uniform. Next, 1 g of a hindered amine-based light stabilizer (Adecastab LA-63P, manufactured by ADEKA) was added to 5 g of dimethyl carbonate, and a hindered phenol-based antioxidant {pentaerythritol-tetrakis [3- (3,5-di-tert-butyl-). 4-Hydroxyphenyl) propionate]} (Irganox 1010, manufactured by BASF), 2 g of a partially hydrolyzed condensate of a silane compound (polybutoxymethoxysiloxane, MKC silicate MS58B30, manufactured by Mitsubishi Chemical Corporation), synthesized. 12 g of the urethane bond-containing oxazolidine compound O-1 obtained in Example 3, 0.2 g of 2-ethylhexyl acid phosphate (JP-508, manufactured by Johoku Chemical Industry Co., Ltd.), fine powder silica (hydrophilic silica, Leoloseal QS-102, 2.6 g (manufactured by Tokuyama Co., Ltd.) was charged and further mixed until the contents became uniform. Then, the foam was defoamed under reduced pressure at 50 to 100 hPa, filled in a container, and sealed to prepare a curable composition.

[Comparative Example 1] to [Comparative Example 3]
Each component was blended with the composition shown in Table 1, and the same operation as in Example 1 was carried out to prepare curable compositions of Comparative Examples 1 to 3. Each component shown in Table 1 is as follows, and the unit is g.
-Isocyanate group-containing urethane prepolymer PU-1 (Synthesis Example 1)
-Isocyanate group-containing urethane prepolymer PU-2 (Synthesis Example 2)
・ Heavy calcium carbonate (Whiten B, manufactured by Shiraishi Calcium)
・ Fatty acid surface treatment Calcium carbonate (Calfine N-40, heat loss 95.0 mg / g, manufactured by Maruo Calcium)
-Hindered phenolic antioxidant {pentaerythritol-tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate]} (Irganox 1010, manufactured by BASF)
・ Hindered amine-based light stabilizer (ADEKA STAB LA-63P, manufactured by ADEKA)
-Partial hydrolysis condensate of silane compound (polybutoxymethoxysiloxane, MKC silicate MS58B30, manufactured by Mitsubishi Chemical Corporation)
-Urethane bond-containing oxazolidine compound O-1 (Synthesis Example 3)
-2-Ethylhexyl acid phosphate (JP-508, manufactured by Johoku Chemical Industry Co., Ltd.)
・ Paratoluenesulfonyl isocyanate ・ Fine powder silica (hydrophilic silica, Leoloseal QS-102, manufactured by Tokuyama Corporation)

<Evaluation of curable composition>
The following evaluations were carried out using the curable compositions of Example 1 and Comparative Examples 1 to 3. The evaluation results are shown in Table 1.

[Drop Clothes Adhesion Prevention]
a) Anti-adhesion of the curing sheet (5 ° C 40% RH)
A joint having a width of 30 mm, a depth of 10 mm, and a length of 100 mm was prepared on a slate plate using a 10 mm square backer. The joint was filled with a curable composition, and the excess was scraped off with a spatula to flatten the surface to prepare a test piece.
The test piece was immediately cured in an environment (indoor) at 5 ° C. and 40% RH for 3 or 5 days. A curing sheet (polymasker (cloth tape + polyethylene sheet), manufactured by Otsuka Brush Manufacturing Co., Ltd.) was attached to the surface of the curable composition after curing so as to be orthogonal to the longitudinal direction of the joint. One day after the application, the curing sheet was peeled off, and the peeling condition was visually confirmed. When the surface of the curable composition was touched at this time, the surface was cured, but the inside was not cured.
b) Anti-adhesion of the curing sheet (23 ° C 50% RH)
A joint having a width of 30 mm, a depth of 10 mm, and a length of 100 mm was prepared on a slate plate using a 10 mm square backer. The joint was filled with a curable composition, and the excess was scraped off with a spatula to flatten the surface to prepare a test piece.
The specimen was immediately cured in an environment (indoor) at 23 ° C. and 50% RH for 1 or 2 days. A curing sheet (polymasker (cloth tape + polyethylene sheet), manufactured by Otsuka Brush Manufacturing Co., Ltd.) was attached to the surface of the curable composition after curing so as to be orthogonal to the longitudinal direction of the joint. One day after the application, the curing sheet was peeled off, and the peeling condition was visually confirmed. When the surface of the curable composition was touched at this time, the surface was cured, but the inside was not cured.
The adhesion prevention property of the curing sheet was evaluated as follows.
evaluation:
⊚: The curing sheet does not adhere to the surface of the curable composition and peels off cleanly.
◯: The curing sheet slightly adheres to the surface of the curable composition, but peels off cleanly.
Δ: The curing sheet partially adheres to the surface of the curable composition, and when it is peeled off, the surface layer of the curable composition is pulled and there is a design defect.
X: The curing sheet adheres to the surface of the curable composition and cannot be peeled off unless it is pulled strongly. When the curing sheet is peeled off, most of the surface layer of the curable composition is pulled and there is a design defect.

[Pollution prevention]
<Black silica sand contamination>
A joint having a width of 20 mm, a depth of 20 mm, and a length of 100 mm was prepared on a slate plate using a 10 mm square backer. The joint was filled with a curable composition, and the excess was scraped off with a spatula to flatten the surface to prepare a test piece.
The test piece was immediately cured in an environment (indoor) at 23 ° C. and 50% RH for 7 days. Black silica sand (8 Black, manufactured by Keimu Buesera) was sprinkled on the surface of the curable composition after curing, the test piece was immediately turned over, and the bottom of the slate plate was tapped by hand to remove excess black silica sand. The state of the black silica sand (dirt) remaining on the surface of the curable composition was visually observed, and the antifouling property during curing was evaluated as follows.
evaluation:
◯: A clean state with almost no adhesion of black silica sand on the surface of the curable composition.
X: A state in which a large amount of black silica sand adheres to the surface of the curable composition and becomes black and dirty.

[Surface tack]
a) A square frame of 50 mm in length × 50 mm in width × 10 mm in depth is made on a finger-touch slate plate using a 10 mm square backer, the curable composition is filled in this frame, and the excess is scraped off with a spatula. The surface was finished flat and used as a test piece. The test piece was allowed to stand in an environment (indoor) at 23 ° C. and 50% RH for 7 days, and then the surface of the curable composition was touched to evaluate the surface tack (stickiness).
evaluation:
◯: The surface of the curable composition is not sticky.
X: The surface of the curable composition is sticky.
b) Tackiness measurement A square frame of 50 mm in length × 50 mm in width × 10 mm in depth is made on a slate plate using a 10 mm square backer, the curable composition is filled in this frame, and the excess is scraped off with a spatula. The surface was finished flat and used as a test piece. After allowing the test piece to stand in an environment (indoor) at 23 ° C. and 50% RH for 7 days, the tackiness (adhesive strength) of the surface of the curable composition using a tackiness checker (HTC-1, manufactured by Toyo Seiki Seisakusho Co., Ltd.). ) [N] was measured. The measured temperature is 23 ° C., the contact is a surface indenter (type AL-R1), the contact crimping force is 10N, and the crimping time is 3 seconds.

[Movement resistance]
Two mortars with a length of 50 mm, a width of 50 mm and a thickness of 25 mm were prepared, a primer (OP-2019, manufactured by Auto Chemical Industry Co., Ltd.) was applied to the adherend surface (50 mm x 25 mm), and the mortar was cured at 23 ° C. for 30 minutes. .. Next, a 10 mm square backer was double-pasted on the adherend surface, and the mortar was aligned so that the square backer was the base of the joint, and a test piece having a joint between the mortars having a length of 50 mm, a width of 20 mm, and a depth of 15 mm was prepared. did. The test piece was fixed to a repeat tester according to JIS A 1439 (2016) Test method for building sealants 5.12.1 g), the joints were filled with a curable composition, and then the excess was removed with a spatula to remove the surface. Was finished smoothly. Immediately after the repeat tester was operated and the joint was subjected to an enlarged displacement of 1 mm or 2 mm, the state of the surface of the curable composition was visually observed, and the movement resistance at the time of curing was evaluated as follows. The expanded displacement was an approximate sine wave, and 1 cycle / 24 hours. That is, it is a cycle in which the joint width is expanded by 1 mm or 2 mm and then returned to the original joint width in 24 hours. The test was conducted in an environment (indoor) of 23 ° C. and 50% RH.
evaluation:
◯: No wrinkles are generated on the surface of the curable composition.
Δ: Slight wrinkles are generated on the surface of the curable composition.
X: Wrinkles are generated on the surface of the curable composition as a whole, which spoils the appearance.

[Storage stability]
<Initial>
After preparing the curable composition, it was placed in a paper tube cartridge, sealed, and allowed to stand in an environment (indoor) at 23 ° C. and 50% RH for one day.
<After heat storage>
After preparing the curable composition, it was placed in a paper tube cartridge, sealed, and placed in an oven at 60 ° C. for 30 days for heating and storage. After heat storage, the paper tube cartridge was taken out from an oven at 60 ° C. and allowed to stand in an environment (indoor) at 23 ° C. and 50% RH for one day.

[Extrudability]
Using a manual cartridge gun, the paper tube cartridges at the initial stage and after heat storage were extruded, and the extrudability was evaluated from the situation. The discharge port (plastic nozzle) of the paper tube cartridge was set to 8 mmΦ.
Evaluation ○: The contents will come out easily if extruded △: The contents will not come out unless it is extruded strongly ×: The contents will not come out unless it is extruded fairly strongly [Viscosity increase rate]
The viscosity of the curable composition at the initial stage and after heat storage was measured with an E-type viscometer (25 ° C, 30-fold cone, 10 rpm), and the viscosity increase rate of the curable composition (viscosity after heat storage / initial viscosity). Asked.

[Removability of curing tape]
A joint having a width of 20 mm, a depth of 20 mm, and a length of 100 mm was prepared on a slate plate using a 10 mm square backer. A curing tape (masking tape, width 17 mm, manufactured by Kamoi Kako Paper Co., Ltd.) was attached along the joints to prepare a test piece.
The curable composition at the initial stage and after heat storage was cast into the joints of the test piece, and the surface of the curable composition was flattened with a spatula. When flattened, excess curable composition was attached to the curing tape. Then, the curable composition was cured for 30 minutes or 60 minutes in an environment of 35 ° C. and 70% RH (incubator), and then the curing tape was peeled off. The condition when the curing tape was peeled off was visually confirmed, and the peeling property of the curing tape was evaluated.
Evaluation ○: The curable composition on the curing tape peels off cleanly and does not cause any design defects. Δ: The curable composition on the curing tape is partially pulled by the curing tape and some burrs are generated near the joints. , Causes design defects ×: The curable composition on the curing tape is pulled by the curing tape and does not peel off cleanly, and when the curing tape is forcibly pulled, burrs are generated and burrs remain on the joints or joints, and the design Causes the above problems

From the results of Example 1, it can be seen that the curable composition of the present invention is excellent in the adhesion prevention property of the curing sheet and the movement resistance. Further, it can be seen that the curable composition of the present invention is not contaminated even when the surface thereof is sprinkled with black silica sand, the surface is not sticky due to touch, and the tackiness (adhesive strength) of the surface is low. Further, it can be seen that the curable composition of the present invention has a low rate of increase in viscosity after storage at 60 ° C. for 30 days, good extrudability even after storage, and excellent peelability of curing tape.
On the other hand, the curable compositions of Comparative Example 1 and Comparative Example 3 had a large increase in viscosity after storage at 60 ° C. for 30 days, and the extrudability was deteriorated. The viscosity of the curable composition of Comparative Example 3 after storage at 60 ° C. for 30 days became too high, and the viscosity could not be measured. Further, it can be seen that the curable compositions of Comparative Example 1 and Comparative Example 3 have poor peelability of the curing tape at 35 ° C. and 70% RH. Since the curable composition of Comparative Example 2 had tack (stickiness) on its surface, the value of tackness was large, and contamination by black silica sand was observed.

As described above, the curable composition of the present invention has excellent curing sheet adhesion prevention property, movement resistance, curing tape peeling property, no tack (stickiness) on the surface, stain prevention property, and stability after heat storage. Therefore, it can be suitably used as a sealing material composition, a waterproof material composition, an adhesive composition, and a coating material composition. Further, the curable composition of the present invention can be suitably used for construction and civil engineering. In particular, it can be suitably used as a sealing material composition for working joints.

Claims (13)

A curable composition containing an isocyanate group-containing resin, an oxazolidine compound, a bismuth compound, and a phosphoric acid ester compound .
The bismuth compound is a bismuth compound which is a salt of trivalent bismuth and an organic acid.
The phosphate ester compound is ethyl acid phosphate, butyl acid phosphate, dibutylpyrophosphate, butoxyethyl acid phosphate, 2-ethylhexyl acid phosphate, alkyl (C12, C14, C16, C18) acid phosphate, isotridecyl acid phosphate, oleyl. At least one phosphate ester compound selected from acid phosphate and tetracosyl acid phosphate.
A curable composition, characterized in that. The curable composition according to claim 1 , wherein the bismuth compound is tris (2-ethylhexanoic acid) bismuth (III). The curable composition according to claim 1 or 2 , wherein the blending amount of the bismuth compound is 0.005 to 5 parts by mass with respect to 100 parts by mass of the isocyanate group-containing resin. Any one of claims 1 to 3 , wherein the blending amount of the phosphoric acid ester compound is 0.01 to 5 parts by mass with respect to 100 parts by mass of the total amount of the isocyanate group-containing resin and the oxazolidine compound. The curable composition according to the section. The curable composition according to any one of claims 1 to 4 , wherein the isocyanate group-containing resin has a branch density of 0.03 mmol / g or more. The curable composition according to any one of claims 1 to 5 , wherein the isocyanate group-containing resin has a photoreactive unsaturated bond in the molecule. The curable composition according to any one of claims 1 to 6 , further comprising a surface-treated calcium carbonate having a heat loss of 50 to 150 mg / g. The curable composition according to any one of claims 1 to 7 , further comprising fine powdered silica. The curable composition according to claim 8 , wherein the fine powdered silica has a silanol group of 0.5 to 3 elements / nm ² on the surface thereof. The curable composition according to any one of claims 1 to 9 , further comprising a silane compound represented by the following general formula (1) and / or a partially hydrolyzed condensate of the silane compound.
R _4-m Si- (OR ¹ ) _m (1)
(In the formula (1), R represents a monovalent hydrocarbon group having 1 to 6 carbon atoms, and when there are a plurality of Rs, they may be the same or different. R ¹ is 1 having 1 or more carbon atoms. Although it is a valent hydrocarbon group, at least one of (OR ¹ ) is an alkoxy group having 2 to 6 carbon atoms. When there are a plurality of (OR ¹ ), they may be the same or different. Is an integer from 1 to 4.) Further, at least one selected from a curing accelerating catalyst, a plasticizer, a weather resistance stabilizer, a filler, a rocking denaturing agent, an adhesiveness improving agent, a storage stability improving agent (dehydrating agent), a colorant and an organic solvent. The curable composition according to any one of claims 1 to 10 , which comprises an additive. The curable composition according to any one of claims 1 to 11 , wherein the curable composition is a curable composition for construction or civil engineering. The curable composition according to any one of claims 1 to 12 , wherein the curable composition is a sealing material composition, a waterproof material composition, an adhesive composition or a coating material composition. thing.