Surface coating agent composition of curable composition and construction method using the same

Abstract

To provide a surface coating agent composition of a curable composition which imparts excellent contamination prevention property and matting property to the surface of the curable composition while having excellent elasticity, and a construction method for forming a cured film of the surface coating agent composition on the surface of the curable composition.SOLUTION: There are provided a surface coating agent composition of a curable composition contains (A) an isocyanate group-containing urethane resin, (B) an isocyanate group-containing (meth)acrylic urethane resin, and (C) an organic solvent; and a construction method for coating or spraying the surface coating agent composition onto the surface of the curable composition, and forming a cured film on the surface of the curable composition.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a surface coating composition for a curable composition that has excellent stretchability and imparts excellent stain resistance and matte properties to the surface of the curable composition, and to an application method using the same. [Background technology]

[0002] Curable compositions such as sealant compositions, waterproofing compositions, and coating compositions containing curable resins such as polyurethane resins and modified silicone resins are widely used for the purpose of waterproofing and surface protection of buildings and civil engineering structures. After these curable compositions are poured or applied to a construction site, if dust or dirt adheres to the composition during curing, the surface will become contaminated, resulting in design defects.

[0003] Furthermore, matte materials are often used for building and civil engineering structure components to create a subdued texture, and sand-like (sand-sprinkled or sandstone-like) materials are often used to create a luxurious feel. If a glossy curable composition is used for such components, the gloss may stand out in those areas, resulting in design defects.

[0004] To solve this problem, there is a method of improving the contamination resistance of the curable composition surface by applying or spraying a surface coating composition onto the surface of the curable composition (for example, Patent Document 1). Also, there is a method of blending an amine into the curable composition to reduce the gloss of the curable composition surface (for example, Patent Document 2).

[0005] Patent Document 1 discloses a technology for preventing adhesion of dust and other particles to the sealant surface and improving the contamination resistance of the sealant surface by applying a solution of polyisocyanate urethane prepolymer made from raw materials such as polyether polyol, trimethylolpropane, and polycaprolactone triol to the surface of a curable composition such as a polyurethane sealant or modified silicone sealant, thereby forming a polyurethane coating film on the sealant surface. However, in order to prevent contamination of the surface of a curable composition such as a sealant, a surface coating composition that exhibits sufficient contamination prevention immediately after pouring is preferred, and the surface coating composition of Patent Document 1 was not necessarily satisfactory. Furthermore, curable compositions used in joints that undergo expansion and contraction displacement, such as working joints, are curable compositions that can follow expansion and contraction displacement, and surface coating compositions used in such areas are also required to have the ability to follow expansion and contraction displacement.

[0006] Patent Document 2 discloses a technique for imparting matte properties to the surface of a curable composition by blending an amine into the curable composition containing a crosslinkable silyl group-containing resin. However, when blending an amine to impart matte properties, there is a risk that it may take time for the matte properties to appear at low temperatures, and blending an epoxy compound to improve adhesion to an adherend may increase the viscosity of the curable composition, which limits the design of the curable composition. Therefore, a new attempt to impart matte properties to the surface of a curable composition is desired. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 1-201386 [Patent Document 2] Japanese Patent Application Laid-Open No. 2003-89742 Summary of the Invention [Problem to be solved by the invention]

[0008] In view of the above circumstances, an object of the present invention is to provide a surface coating composition for a curable composition that has excellent stretchability and imparts excellent stain resistance and matte properties to the surface of the curable composition, and to provide an application method for forming a cured film of the surface coating composition on the surface of the curable composition. [Means for solving the problem]

[0009] The gist of the constitution of the surface coating agent composition of the curable composition of the present invention is as follows. [1] A surface coating composition of a curable composition, characterized by containing (A) an isocyanate group-containing urethane resin, (B) an isocyanate group-containing (meth)acrylic urethane resin, and (C) an organic solvent. [2] The (A) isocyanate group-containing urethane resin is a reaction product of an organic isocyanate compound and an active hydrogen-containing compound that does not contain an isocyanate group-reactive functional group-containing (meth)acrylic resin, The surface coating agent composition of the curable composition according to [1], characterized in that the (B) isocyanate group-containing (meth)acrylic urethane resin is a reaction product of an organic isocyanate compound and an active hydrogen-containing compound including an isocyanate group-reactive functional group-containing (meth)acrylic resin. [3] The surface coating agent composition of the curable composition according to [2], characterized in that the active hydrogen-containing compound not containing the isocyanate group-reactive functional group-containing (meth)acrylic resin is one or more active hydrogen-containing compounds selected from the group consisting of polymer polyols with a number average molecular weight of 1,000 or more, polymer monools with a number average molecular weight of 1,000 or more, low molecular weight polyols with a number average molecular weight of less than 1,000, low molecular weight monools with a number average molecular weight of less than 1,000, and silane compounds with an isocyanate group-reactive functional group (excluding the isocyanate group-reactive functional group-containing (meth)acrylic resin). [4] The surface coating agent composition of the curable composition according to [1] or [2], characterized in that the (B) isocyanate group-containing (meth)acrylic urethane resin is a resin in which an organic isocyanate compound is pendant on an active hydrogen-containing compound including an isocyanate group-reactive functional group-containing (meth)acrylic resin. [5] A surface coating agent composition of the curable composition according to [2], characterized in that the isocyanate group-reactive functional group is one or more functional groups selected from the group consisting of -COOH, -OH, -NH2, -NH and -SH. [6] The surface coating agent composition of the curable composition according to [1] or [2], characterized in that the blending ratio of the (A) isocyanate group-containing urethane resin and the (B) isocyanate group-containing (meth)acrylic urethane resin is 10 / 90 to 90 / 10, in terms of the number of moles of isocyanate groups in the (B) isocyanate group-containing (meth)acrylic urethane resin relative to the number of moles of isocyanate groups in the (A) isocyanate group-containing (meth)urethane resin. [7] The surface coating agent composition of the curable composition according to [1] or [2], characterized in that the total amount of the (A) isocyanate group-containing urethane resin and the (B) isocyanate group-containing (meth)acrylic urethane resin is 1 to 70 mass % in the surface coating agent composition. [8] The surface coating agent composition of the curable composition according to [1] or [2], wherein the (C) organic solvent contains 5 to 70 mass % of a hydrocarbon organic solvent having a boiling point (initial boiling point) of 150°C or higher. [9] A surface coating agent composition of the curable composition according to [1] or [2], further comprising a modified organic isocyanate compound having one or more bonds selected from the group consisting of a uretdione bond, an isocyanurate bond, an allophanate bond, a biuret bond, a uretonimine bond, a carbodiimide bond, a urethane bond, and a urea bond.

[10] A surface coating composition of the curable composition according to [1] or [2], further comprising a matting agent.

[11] The surface coating composition of the curable composition according to

[10] , wherein the matting agent is one or more matting agents selected from the group consisting of polyolefins, oxidized polyolefins, and silica.

[12] A construction method characterized by applying or spraying a surface coating composition containing (A) an isocyanate group-containing urethane resin, (B) an isocyanate group-containing (meth)acrylic urethane resin, and (C) an organic solvent onto the surface of a curable composition, thereby forming a cured film on the surface of the curable composition. [Effects of the Invention]

[0010] According to an embodiment of the surface coating composition of the curable composition of the present invention, by containing (A) an isocyanate group-containing urethane resin, (B) an isocyanate group-containing (meth)acrylic urethane resin, and (C) an organic solvent, it is possible to obtain a surface coating composition of the curable composition that has excellent elasticity and imparts excellent contamination prevention properties to the surface of the curable composition. By further containing a matting agent, the surface coating composition of the curable composition of the present invention can impart matting properties in addition to excellent elasticity and contamination prevention properties to the surface of the curable composition.

[0011] According to an embodiment of the surface coating agent composition of the curable composition of the present invention, the (A) isocyanate group-containing urethane resin is a reaction product of an organic isocyanate compound and an active hydrogen-containing compound that does not contain a (meth)acrylic resin containing an isocyanate group-reactive functional group, and the (B) isocyanate group-containing (meth)acrylic urethane resin is a reaction product of an organic isocyanate compound and an active hydrogen-containing compound that contains a (meth)acrylic resin containing an isocyanate group-reactive functional group. This allows the curable composition to have excellent elasticity and to more reliably exhibit excellent contamination prevention properties on the surface of the curable composition.

[0012] According to an embodiment of the surface coating agent composition of the curable composition of the present invention, the active hydrogen-containing compound that does not contain an isocyanate group-reactive functional group-containing (meth)acrylic resin is one or more active hydrogen-containing compounds selected from the group consisting of polymer polyols having a number average molecular weight of 1,000 or more, polymer monools having a number average molecular weight of 1,000 or more, low molecular weight polyols having a number average molecular weight of less than 1,000, low molecular weight monools having a number average molecular weight of less than 1,000, and isocyanate group-reactive functional group-containing silane compounds (excluding isocyanate group-reactive functional group-containing (meth)acrylic resins), thereby enabling the curable composition to have excellent elasticity and to more reliably exhibit excellent contamination prevention properties on the surface of the curable composition.

[0013] According to an embodiment of the surface coating agent composition of the curable composition of the present invention, the (B) isocyanate group-containing (meth)acrylic urethane resin is a resin in which an organic isocyanate compound is pendant on an active hydrogen-containing compound including an isocyanate group-reactive functional group-containing (meth)acrylic resin, and therefore the surface of the curable composition can be more reliably prevented from being contaminated while having excellent elasticity.

[0014] According to an embodiment of the surface coating agent composition of the curable composition of the present invention, the blending ratio of the (A) isocyanate group-containing urethane resin and the (B) isocyanate group-containing (meth)acrylic urethane resin is 10 / 90 to 90 / 10, in terms of the number of moles of isocyanate groups in the (B) isocyanate group-containing (meth)acrylic urethane resin relative to the number of moles of isocyanate groups in the (A) isocyanate group-containing urethane resin, thereby enabling the curable composition to have excellent elasticity while more reliably exhibiting excellent contamination prevention properties on the surface of the curable composition.

[0015] According to an embodiment of the surface coating composition of the curable composition of the present invention, the total amount of the (A) isocyanate group-containing urethane resin and the (B) isocyanate group-containing (meth)acrylic urethane resin is 1 to 70 mass % in the surface coating composition, whereby the drying properties of the surface coating composition are optimized, and a cured film of the surface coating composition can be reliably formed on the surface of the curable composition even during curing of the curable composition.

[0016] According to an embodiment of the surface coating agent composition of the curable composition of the present invention, the (C) organic solvent is By including 5 to 70 mass % of a hydrocarbon organic solvent having a boiling point (initial boiling point) of 150° C. or higher, the masking tape peelability of the surface coating agent composition of the curable composition is improved.

[0017] According to an embodiment of the application method using the surface coating composition of the curable composition of the present invention, a surface coating composition containing (A) an isocyanate group-containing urethane resin, (B) an isocyanate group-containing (meth)acrylic urethane resin, and (C) an organic solvent is applied or sprayed onto the surface of the curable composition to form a cured film on the surface of the curable composition. This allows the cured film formed on the surface of the curable composition to have excellent stretchability and also imparts excellent contamination prevention properties to the surface of the curable composition. DETAILED DESCRIPTION OF THE INVENTION

[0018] The surface coating composition of the curable composition of the present invention and the application method using the surface coating composition of the curable composition will be described in detail below.

[0019] The surface coating agent composition of the curable composition of the present invention is characterized by containing (A) an isocyanate group-containing urethane resin, (B) an isocyanate group-containing (meth)acrylic urethane resin, and (C) an organic solvent. The surface coating agent composition of the curable composition of the present invention is a surface coating agent composition applied to the surface of the curable composition. According to an embodiment of the surface coating agent composition of the curable composition of the present invention, by containing (A) an isocyanate group-containing urethane resin, (B) an isocyanate group-containing (meth)acrylic urethane resin, and (C) an organic solvent, it is possible to obtain a surface coating agent composition of the curable composition that has excellent elasticity and imparts excellent contamination prevention properties to the surface of the curable composition.

[0020] Each component of the surface coating composition of the curable composition of the present invention will be described in detail below.

[0021] <(A) Isocyanate group-containing urethane resin> The (A) isocyanate group-containing urethane resin is an isocyanate group-containing urethane resin other than the (meth)acrylic urethane resin containing an isocyanate group, which is the component (B). The (A) isocyanate group-containing urethane resin is not particularly limited as long as it is an isocyanate group-containing urethane resin other than the (meth)acrylic urethane resin containing an isocyanate group. However, from the viewpoint of more reliably exhibiting excellent contamination prevention properties on the surface of the curable composition, a reaction product of an organic isocyanate compound and an active hydrogen-containing compound that does not contain a (meth)acrylic resin containing an isocyanate group-reactive functional group is preferred.

[0022] The reaction product of an organic isocyanate compound and an active hydrogen-containing compound that does not contain an isocyanate group-reactive functional group-containing (meth)acrylic resin (hereinafter, sometimes referred to as an "isocyanate group-containing urethane prepolymer") can be produced by reacting an organic isocyanate compound with an active hydrogen-containing compound that does not contain an isocyanate group-reactive functional group-containing (meth)acrylic resin all at once or sequentially in a range where the molar ratio of isocyanate groups to active hydrogen is greater than 1.0, preferably 1.2 or more to prevent the viscosity of the isocyanate group-containing urethane prepolymer from increasing and reducing the workability of the surface coating composition, and 10 or less to reduce the amount of carbon dioxide gas generated by the reaction of the isocyanate groups with water and prevent foaming during curing, so that isocyanate groups remain in the isocyanate group-containing urethane prepolymer.

[0023] The isocyanate group content in the isocyanate group-containing urethane prepolymer is preferably in the range of 1% by mass or more to prevent the viscosity of the isocyanate group-containing urethane prepolymer from increasing and reducing the workability of the surface coating composition, and 15% by mass or less to reduce the amount of carbon dioxide gas generated by the reaction of the isocyanate groups with water and prevent foaming during curing.

[0024] The number average molecular weight of the isocyanate group-containing urethane prepolymer is preferably 300 or more, more preferably 300 to 10,000, even more preferably 300 to 5,000, and particularly preferably 300 to 3,000.

[0025] In the present invention, the number average molecular weight and the weight average molecular weight described below are values ​​measured by gel permeation chromatography (GPC) in terms of polystyrene. Specific measurement conditions are shown below. Device name: HLC-8320GPC (Tosoh Corporation) Eluent:THF Temperature: 40℃ Detector: RI

[0026] The isocyanate group-containing urethane prepolymer can be produced by a conventionally known method. Specifically, a reaction vessel made of glass, stainless steel, or the like is charged with an organic isocyanate compound and an active hydrogen-containing compound that does not contain an isocyanate group-reactive functional group-containing (meth)acrylic resin, and, if necessary, an organic solvent or a reaction catalyst is used to react the mixture with stirring at 50 to 120°C. Since the isocyanate group reacts with moisture or other water, the viscosity of the isocyanate group-containing urethane prepolymer increases. Therefore, it is preferable to replace the atmosphere in the vessel with nitrogen gas beforehand or to carry out the reaction under a nitrogen gas stream.

[0027] As the organic solvent, the same organic solvents as (C) described below can be used.

[0028] Examples of reaction catalysts that can be used include salts of metals such as zinc, tin, zirconium, bismuth, cobalt, manganese, and iron with organic acids such as octylic acid and naphthenic acid, salts of organic metals such as tetra-n-butoxytitanium, dibutyltin dilaurate, and dioctyltin dilaurate with organic acids, and organic amines such as triethylenediamine, triethylamine, tri-n-butylamine, DBU, and DBE, and salts thereof. These may be used alone or in combination of two or more.

[0029] Organic isocyanate compounds The organic isocyanate compound is a compound having one or more isocyanate groups in the molecule, and specific examples thereof include organic polyisocyanates, modified organic polyisocyanates, and organic monoisocyanates.

[0030] The organic polyisocyanate is a compound having two or more isocyanate groups in the molecule. Specifically, toluene polyisocyanates such as 2,4-toluene diisocyanate and 2,6-toluene diisocyanate, diphenylmethane polyisocyanates such as 4,4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate and 2,2'-diphenylmethane diisocyanate, 1,2-phenylene diisocyanate, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, 2,4,6-trimethylphenyl-1,3-diisocyanate, 2, Examples of the isocyanate include phenylene polyisocyanates such as 4,6-triisopropylphenyl-1,3-diisocyanate, naphthalene polyisocyanates such as 1,4-naphthalene diisocyanate and 1,5-naphthalene diisocyanate, and aromatic polyisocyanates such as chlorophenylene-2,4-diisocyanate, 4,4'-diphenyl ether diisocyanate, 3,3'-dimethyldiphenylmethane-4,4'-diisocyanate and 3,3'-dimethoxydiphenyl-4,4'-diisocyanate. Also, 1,6-hexamethylene diisocyanate, 1,5-pentamethylene diisocyanate, 1,4-tetramethylene diisocyanate, 2,2,4-trimethyl-1,6-hexamethylene diisocyanate, 2,4,4-trimethyl-1,6-hexamethylene diisocyanate, decamethylene diisocyanate, lysine diisocyanate Examples of suitable organic polyisocyanates include aliphatic polyisocyanates such as benzophenone, aromatic aliphatic polyisocyanates such as o-xylylene diisocyanate, m-xylylene diisocyanate, and p-xylylene diisocyanate, and alicyclic polyisocyanates such as 1,4-cyclohexyl diisocyanate, isophorone diisocyanate, hydrogenated toluene diisocyanate, hydrogenated xylylene diisocyanate, and hydrogenated diphenylmethane diisocyanate. Also suitable organic polyisocyanates include polymeric isocyanates such as polymethylene polyphenyl polyisocyanate and crude toluene diisocyanate. These organic polyisocyanates may be used alone or in combination of two or more.

[0031] Among these organic polyisocyanates, organic polyisocyanates containing at least one of aliphatic polyisocyanates, araliphatic polyisocyanates, and alicyclic polyisocyanates are preferred in terms of improving the weather resistance of the surface coating composition.

[0032] The modified organic polyisocyanate is obtained by modifying the above-mentioned organic polyisocyanate or a mixture of an organic polyisocyanate and an organic monoisocyanate described below, and is a compound having at least one of uretdione bond, isocyanurate bond, allophanate bond, biuret bond, uretonimine bond, carbodiimide bond, urethane bond, and urea bond in the molecule and having two or more isocyanate groups in the molecule. These modified organic polyisocyanates may be used alone or in combination of two or more.

[0033] Among these modified organic polyisocyanates, modified organic polyisocyanates containing at least one of modified aliphatic polyisocyanates, modified araliphatic polyisocyanates, and modified alicyclic polyisocyanates are preferred in terms of improving the weather resistance of the surface coating composition.Moreover, as the modified organic polyisocyanate, modified organic polyisocyanates having an isocyanurate bond are preferred.

[0034] The organic monoisocyanate is a compound having one isocyanate group in the molecule. Specific examples include n-butyl monoisocyanate, n-hexyl monoisocyanate, n-hexadecyl monoisocyanate, n-octadecyl monoisocyanate, p-isopropylphenyl monoisocyanate, and p-benzyloxyphenyl monoisocyanate. These organic monoisocyanates may be used alone or in combination of two or more. Although the organic monoisocyanate can be used alone as an organic isocyanate compound, it is preferable to use it in combination with an organic polyisocyanate and / or a modified organic polyisocyanate because it provides excellent formability of the cured film of the surface coating agent composition.

[0035] Active hydrogen-containing compounds that do not contain (meth)acrylic resins containing isocyanate-reactive functional groups The active hydrogen-containing compound that does not contain an isocyanate group-reactive functional group-containing (meth)acrylic resin is a compound that does not contain an isocyanate group-reactive functional group-containing (meth)acrylic resin and has one or more active hydrogen (groups) in the molecule. Specific examples include polymer polyols, polymer monools, low molecular weight polyols, low molecular weight monools, and isocyanate group-reactive functional group-containing silane compounds that do not contain an isocyanate group-reactive functional group-containing (meth)acrylic resin. These active hydrogen-containing compounds that do not contain an isocyanate group-reactive functional group-containing (meth)acrylic resin may be used alone or in combination of two or more. In the present invention, "polymer" refers to a compound having a number average molecular weight of 1,000 or more, and "low molecular" refers to a compound having a number average molecular weight of less than 1,000.

[0036] Specific examples of polymer polyols include polyester polyols, polycarbonate polyols, polyoxyalkylene polyols, hydrocarbon polyols, and animal and plant polyols. and copolyols thereof.

[0037] The number average molecular weight of the polymer polyol is preferably 1,000 to 30,000, more preferably 1,000 to 20,000, and particularly preferably 1,000 to 10,000. The weight average molecular weight of the polymer polyol is preferably 1,500 to 50,000, more preferably 2,000 to 40,000, and particularly preferably 2,000 to 20,000.

[0038] Examples of polyester polyols include polycarboxylic acids such as succinic acid, adipic acid, sebacic acid, azelaic acid, terephthalic acid, isophthalic acid, orthophthalic acid, hexahydroterephthalic acid, hexahydroisophthalic acid, hexahydroorthophthalic acid, naphthalenedicarboxylic acid, and trimellitic acid, anhydrides of these polycarboxylic acids, and alkyl esters of these polycarboxylic acids such as methyl esters and ethyl esters, and polyesters containing at least one of ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3 Examples of polyester polyols include polyester polyols obtained by reacting one or more low-molecular-weight polyols such as 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, neopentyl glycol, 1,8-octanediol, 1,9-nonanediol, diethylene glycol, dipropylene glycol, 1,4-cyclohexanedimethanol, an ethylene oxide or propylene oxide adduct of bisphenol A, trimethylolpropane, glycerin, and pentaerythritol. Examples of polyester polyols include polyesteramide polyols obtained by reacting these carboxylic acids and low-molecular-weight polyols with one or more low-molecular-weight polyamines such as butylenediamine, hexamethylenediamine, xylylenediamine, and isophoronediamine, and low-molecular-weight aminoalcohols such as monoethanolamine and diethanolamine. Further, examples of polyester polyols include lactone-based polyester polyols obtained by ring-opening polymerization of cyclic ester (lactone) monomers such as ε-caprolactone and γ-valerolactone using low molecular weight polyols, low molecular weight polyamines, and low molecular weight amino alcohols as initiators.

[0039] Examples of polycarbonate polyols include polyols obtained by the dehydrochlorination reaction of the low-molecular-weight polyols used in the synthesis of the above-mentioned polyester polyols with phosgene, or by the transesterification reaction of the above-mentioned low-molecular-weight polyols with diethylene carbonate, dimethyl carbonate, diethyl carbonate, or diphenyl carbonate.

[0040] Examples of polyoxyalkylene polyols include the low molecular weight polyols, low molecular weight polyamines, and low molecular weight amino alcohols used in the synthesis of the above-mentioned polyester polyols, as well as polyoxyethylene polyols, polyoxypropylene polyols, polyoxybutylene polyols, polyoxytetramethylene polyols, and poly-(oxyethylene)-(oxypropylene)-random or block copolymer polyols obtained by ring-opening addition polymerization or copolymerization of one or more cyclic ether compounds such as ethylene oxide, propylene oxide, butylene oxide, and tetrahydrofuran using one or more sugar-based low molecular weight polyhydric alcohols such as sorbitol, mannitol, sucrose, and glucose; and low molecular weight polyhydric phenols such as bisphenol A and bisphenol F as initiators.Furthermore, examples of polyoxyalkylene polyols include polyester ether polyols and polycarbonate ether polyols using the above-mentioned polyester polyols and polycarbonate polyols as initiators. In addition, examples of polyoxyalkylene polyols include polyols obtained by reacting these various ether polyols with organic isocyanate compounds in an excess of hydroxyl groups relative to isocyanate groups, resulting in hydroxyl groups at the molecular ends. The number of alcoholic hydroxyl groups in the polyoxyalkylene polyol is 2 or more, preferably 2 to 4, and particularly 2 to 3 on average per molecule. preferable.

[0041] Examples of catalysts used in synthesizing polyoxyalkylene polyols include alkali metal compound catalysts such as sodium catalysts and potassium catalysts, cationic polymerization catalysts, composite metal cyanide complex catalysts such as zinc hexacyanocobaltate glyme complexes and diglyme complexes, and phosphazene compound catalysts. Among these catalysts, alkali metal compound catalysts and composite metal cyanide complex catalysts are preferred. Furthermore, polyoxyalkylene polyols synthesized using composite metal cyanide complex catalysts are preferred because they have a low total unsaturation degree and a low viscosity of the polyol.

[0042] The term "polyoxyalkylene polyol" and "polyoxyalkylene monool" as used herein means that 50% by mass or more, preferably 80% by mass or more, more preferably 90% by mass or more, and particularly preferably 95% by mass or more of the portion excluding hydroxyl groups per mole of the molecule is composed of polyoxyalkylene, and the remaining portion may be modified with ester, urethane, polycarbonate, polyamide, polyolefin, etc.

[0043] Examples of hydrocarbon polyols include polyolefin polyols such as polybutadiene polyol and polyisoprene polyol; polyalkylene polyols such as hydrogenated polybutadiene polyol and hydrogenated polyisoprene polyol; and halogenated polyalkylene polyols such as chlorinated polypropylene polyol and chlorinated polyethylene polyol.

[0044] Examples of animal and plant polyols include castor oil polyols and silk fibroin.

[0045] The above-mentioned polymer polyols may be used alone or in combination of two or more kinds.

[0046] Examples of the polymer monool include polyoxyalkylene monools such as polyoxypropylene monools obtained by ring-opening addition polymerization of cyclic ether compounds such as propylene oxide using low-molecular-weight monoalcohols such as methyl alcohol, ethyl alcohol, and propyl alcohol as an initiator. The number-average molecular weight of the polymer monool is preferably 1,000 to 10,000. These polymer monools may be used alone or in combination of two or more.

[0047] Examples of low molecular weight polyols include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 2-methyl-1,3-propanediol, 2-butyl-2-ethyl-1,3-propanediol, 1,4-butanediol, neopentyl glycol, 3-methyl-2,4-pentanediol, 2,4-pentanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 2-methyl-2,4-pentanediol, 2,4-diethyl-1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 3,5-heptanediol, 1,8-octanediol, 2-methyl-1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, diethylene glycol, and triethylene glycol. Examples of suitable polyols include low molecular weight aliphatic polyols such as cyclohexanedimethanol, dipropylene glycol, and tripropylene glycol; low molecular weight alicyclic polyols such as cyclohexanedimethanol and cyclohexanediol; low molecular weight aromatic polyols such as 2-10 mole EO adducts of bisphenol A, which are ethylene oxide (hereinafter sometimes referred to as "EO") adducts of bisphenol A, and 2-8 mole PO adducts of bisphenol A, which are propylene oxide (hereinafter sometimes referred to as "PO") adducts of bisphenol A; and low molecular weight polyols having three or more hydroxyl groups, such as trimethylolethane, trimethylolpropane, hexitols, pentitols, glycerin, polyglycerin, pentaerythritol, dipentaerythritol, and tetramethylolpropane. These low molecular weight polyols may be used alone or in combination of two or more kinds.

[0048] Examples of low molecular weight monools include aliphatic monoalcohols having 1 to 20 carbon atoms, such as methyl alcohol, ethyl alcohol, and propyl alcohol. These low molecular weight monools may be used alone or in combination of two or more.

[0049] Silane compounds containing isocyanate-reactive functional groups contain organic functional groups (isocyanate-reactive functional groups) in the molecule that are reactive with isocyanate groups and hydrolyzable (crosslinkable) The isocyanate group-reactive functional group is preferably a functional group having active hydrogen because it easily reacts with the organic isocyanate compound. Examples of the isocyanate group-reactive functional group include at least one of the following functional groups: -COOH, -OH, -NH, -NH, and -SH.

[0050] The number of hydrolyzable (crosslinkable) silyl groups contained in one molecule is preferably 1 to 5, and particularly preferably 1 to 3. The hydrolyzable (crosslinkable) silyl group is preferably one represented by the following general formula, from the viewpoint of ease of crosslinking and ease of production.

[0051] [ka] (In the formula, R represents a hydrocarbon group, and is preferably an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, or an aralkyl group having 7 to 20 carbon atoms, with a methyl group being particularly preferred. When there are multiple Rs, they may be the same or different. The reactive group represented by X is a hydrolyzable group selected from a halogen atom, a hydrogen atom, a hydroxyl group, an alkoxy group, an acyloxy group, a ketoximate group, an amide group, an acid amide group, a mercapto group, an alkenyloxy group, and an aminooxy group, and when there are multiple Xs, they may be the same or different. Of these, X is preferably an alkoxy group, with a methoxy group or an ethoxy group being particularly preferred. a represents an integer of 0, 1, or 2, with 0 or 1 being particularly preferred.)

[0052] Specific examples of compounds having one or more isocyanate-reactive functional groups and one or more hydrolyzable (crosslinkable) silyl groups in the molecule include aminosilane coupling agents and mercaptosilane coupling agents. The organic functional groups of aminosilane coupling agents and mercaptosilane coupling agents have active hydrogen, which makes them preferable because they react relatively easily with the isocyanate groups of organic isocyanate compounds or modified organic polyisocyanates. These compounds may be used alone or in combination of two or more.

[0053] Specific examples of the aminosilane coupling agent include aminomethyltriethoxysilane, N-(2-aminoethyl)aminomethyltrimethoxysilane, aminomethyldiethoxysilane, N-(2-aminoethyl)methyltributoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropylmethyldiethoxysilane, 3-aminoisobutyltrimethoxysilane, N-bis(2-hydroxyethyl)-3-aminopropyltriethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, and N-(aminoethyl)-3-amino-2-methylpropyltrimethoxysilane.

[0054] Specific examples of the mercaptosilane coupling agent include 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropylmethyldiethoxysilane, 3-mercaptopropyltriethoxysilane, 3-mercaptopropylethyldimethoxysilane, 3-mercaptopropylethyldiethoxysilane, 3-mercaptopropyldimethylmethoxysilane, 2-mercaptoethylmethyldimethoxysilane, 2-mercaptoethyltrimethoxysilane, and 2-mercaptoethyltriethoxysilane.

[0055] <(B) Isocyanate group-containing (meth)acrylic urethane resin> The (B) isocyanate group-containing (meth)acrylic urethane resin is an isocyanate group-containing (meth)acrylic urethane resin other than the above-mentioned (A) isocyanate group-containing urethane resin. The isocyanate group-containing (meth)acrylic urethane resin is not particularly limited as long as it is an isocyanate group-containing (meth)acrylic urethane resin, but from the viewpoint of more reliably exhibiting excellent contamination prevention properties on the surface of the curable composition, a reaction product of an organic isocyanate compound with an active hydrogen-containing compound including an isocyanate group-reactive functional group-containing (meth)acrylic resin is preferred, and a resin in which an organic isocyanate compound is pendant on an active hydrogen-containing compound including an isocyanate group-reactive functional group-containing (meth)acrylic resin is particularly preferred. In the present invention, the term "resin in which an organic isocyanate compound is pendant on an active hydrogen-containing compound containing an isocyanate group-reactive functional group-containing (meth)acrylic resin" refers to a resin in which an isocyanate group-reactive functional group bonded to the main chain of an active hydrogen-containing compound containing an isocyanate group-reactive functional group-containing (meth)acrylic resin (for example, the main chain of an isocyanate group-reactive functional group-containing (meth)acrylic resin) is reacted with an isocyanate group of an organic isocyanate compound, and the organic isocyanate compound after the reaction is bonded to the main chain of an active hydrogen-containing compound containing an isocyanate group-reactive functional group-containing (meth)acrylic resin (for example, not at the terminal but in the main chain of the isocyanate group-reactive functional group-containing (meth)acrylic resin).

[0056] The reaction product of an organic isocyanate compound and an active hydrogen-containing compound containing an isocyanate group-reactive functional group-containing (meth)acrylic resin (hereinafter, sometimes referred to as an "isocyanate group-containing (meth)acrylic urethane prepolymer") can be produced by reacting an organic isocyanate compound and an active hydrogen-containing compound containing an isocyanate group-reactive functional group-containing (meth)acrylic resin all at once or sequentially in a range where the molar ratio of isocyanate group / active hydrogen is greater than 1.0, preferably 1.2 or more to prevent the viscosity of the isocyanate group-containing (meth)acrylic urethane prepolymer from increasing and reducing the ease of application or spraying of the surface coating composition, and 10 or less to reduce the amount of carbon dioxide gas generated by the reaction of the isocyanate group with water and prevent foaming during curing, so that the isocyanate group remains in the isocyanate group-reactive functional group-containing (meth)acrylic urethane prepolymer.

[0057] The isocyanate group content in the isocyanate group-containing (meth)acrylic urethane prepolymer is preferably in the range of 1% by mass or more to prevent the viscosity of the isocyanate group-containing (meth)acrylic urethane prepolymer from increasing and reducing the workability of the surface coating composition, and 15% by mass or less to reduce the amount of carbon dioxide gas generated by the reaction of the isocyanate groups with water and prevent foaming during curing.

[0058] The number average molecular weight of the isocyanate group-containing (meth)acrylic urethane prepolymer is preferably 300 or more, more preferably 300 to 10,000, even more preferably 300 to 5,000, and particularly preferably 300 to 3,000.

[0059] The isocyanate group-containing (meth)acrylic urethane prepolymer can be produced by a conventionally known method, specifically, by the same method as the above-mentioned method for producing the isocyanate group-containing urethane prepolymer.

[0060] Organic isocyanate compounds Examples of the organic isocyanate compound include the same organic isocyanate compounds that can be used in synthesizing the above-mentioned (A) isocyanate group-containing urethane resin. The organic isocyanate compounds may be used alone or in combination of two or more.

[0061] Active hydrogen-containing compounds including (meth)acrylic resins containing isocyanate-reactive functional groups Specific examples of active hydrogen-containing compounds containing isocyanate-reactive functional groups include resins in which an isocyanate-reactive functional group is bonded to the (meth)acrylic resin skeleton (the main chain of the (meth)acrylic resin) and / or the terminal of the (meth)acrylic resin. The isocyanate-reactive functional group is preferably at least one of -COOH, -OH, -NH, -NH, and -SH. In the present invention, "(meth)acrylic resin" means "acrylic resin and / or methacrylic resin."

[0062] Examples of the (meth)acrylic resin skeleton structure include those obtained by copolymerizing a (meth)acrylic monomer and an ethylenically unsaturated compound other than a (meth)acrylic monomer in the presence or absence of a solvent by a radical polymerization method such as batch or continuous polymerization.

[0063] Examples of (meth)acrylic monomers include hydroxyl group-containing (meth)acrylic monomers and hydroxyl group-free (meth)acrylic monomers. Hydroxyl group-containing (meth)acrylic monomers are (meth)acrylic monomers having at least one hydroxyl group in the molecule, such as hydroxyalkyl (meth)acrylates (e.g., hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, and hydroxybutyl (meth)acrylate); mono(meth)acrylates of polyhydric alcohols (e.g., pentaerythritol tri(meth)acrylate, glycerin mono(meth)acrylate, pentaerythritol di(meth)acrylate monostearate, dipentaerythritol penta(meth)acrylate, ditrimethylolpropane tri(meth)acrylate, and polypropylene glycol mono(meth)acrylate; and polyhydric (meth)acrylates with residual hydroxyl groups. These compounds may be used alone or in combination of two or more.

[0064] Examples of the (meth)acrylic monomer not containing a hydroxyl group include (meth)acrylic acid, methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, benzyl (meth)acrylate, stearyl (meth)acrylate, cyclohexyl (meth)acrylate, tridecyl (meth)acrylate, ethylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 1,3- Examples of (meth)acrylic acid ester compounds include butanediol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, glycidyl tri(meth)acrylate, and trimethylolpropane tri(meth)acrylate. These compounds may be used alone or in combination of two or more. In the present invention, "(meth)acrylate" means "acrylate and / or methacrylate." In addition, in the present invention, "(meth)acrylic acid" means "acrylic acid and / or methacrylic acid."

[0065] Examples of ethylenically unsaturated compounds other than (meth)acrylic monomers include ethylene Examples of vinyl compounds include propylene, isobutylene, butadiene, chloroprene, styrene, chlorostyrene, 2-methylstyrene, and divinylbenzene.

[0066] The active hydrogen-containing compound containing the isocyanate group-reactive functional group-containing (meth)acrylic resin can be used in combination with the above-mentioned isocyanate group-reactive functional group-containing (meth)acrylic resin, and at least one of high molecular weight polyols, high molecular weight monools, low molecular weight polyols, and low molecular weight monools that can be used in producing the isocyanate group-containing urethane resin (A). When at least one of high molecular weight polyols, high molecular weight monools, low molecular weight polyols, and low molecular weight monools is used in combination, the blending ratio of the isocyanate group-reactive functional group-containing (meth)acrylic resin in the active hydrogen-containing compound containing the isocyanate group-reactive functional group-containing (meth)acrylic resin is preferably 30 mass % or more, and particularly preferably 50 mass % or more.

[0067] The blending ratio of the (A) isocyanate group-containing urethane resin and the (B) isocyanate group-containing (meth)acrylic urethane resin is not particularly limited, but in order to more reliably exhibit excellent contamination prevention properties on the surface of the curable composition, the ratio of the number of moles of isocyanate groups in the (B) isocyanate group-containing (meth)acrylic urethane resin to the number of moles of isocyanate groups in the (A) isocyanate group-containing urethane resin (number of moles of isocyanate groups in the (A) isocyanate group-containing urethane resin / number of moles of isocyanate groups in the (B) isocyanate group-containing (meth)acrylic urethane resin) is preferably 10 / 90 to 90 / 10, more preferably 20 / 80 to 80 / 20, and particularly preferably 30 / 70 to 70 / 30.

[0068] The total blending amount of (A) isocyanate group-containing urethane resin and (B) isocyanate group-containing (meth)acrylic urethane resin in the surface coating composition is not particularly limited, but is preferably 1 to 70 mass %, particularly preferably 5 to 50 mass %, because this optimizes the application or spraying workability and drying properties of the surface coating composition and enables a coating film of the surface coating composition to be reliably formed on the surface of the curable composition even during curing of the curable composition.

[0069] <(C) Organic Solvent> The (C) organic solvent is a component for dissolving the (A) isocyanate group-containing urethane resin, the (B) isocyanate group-containing (meth)acrylic urethane resin, and the optional modified organic isocyanate compound and additives described below, and for dispersing the optional matting agent described below. The (C) organic solvent is also a diluent that adjusts the viscosity of the surface coating composition of the present invention to a level suitable for application or spraying, and is a component for adjusting the drying properties of the cured film of the surface coating composition of the present invention.

[0070] The organic solvent is not particularly limited as long as it is inert and does not exhibit reactivity with (A) the isocyanate group-containing urethane resin, (B) the isocyanate group-containing (meth)acrylic urethane resin, modified organic isocyanate compound, matting agent, and additives. Examples of the organic solvent include ester-based organic solvents such as methyl acetate, ethyl acetate, propyl acetate, butyl acetate, methyl propionate, ethyl propionate, butyl propionate, methyl butyrate, ethyl butyrate, butyl butyrate, butyl stearate, methyl benzoate, ethyl benzoate, propyl benzoate, butyl benzoate, γ-butyrolactone, and diethyl malonate; diethyl ether, dipropyl ether, dibutyl ether, and the like. ether-based organic solvents such as diethyl ether, dioxane, and tetrahydrofuran; amide-based organic solvents such as N,N-dimethylacetamide and N-methylpyrrolidone; ketone-based organic solvents such as acetone, methyl ethyl ketone, methyl propyl ketone, diethyl ketone, butyl methyl ketone, methyl isobutyl ketone, cyclohexanone, methylcyclohexanone, isophorone, and acetophenone; and acetate-based organic solvents such as ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate, and methyl-1,3-butylene glycol acetate.

[0071] Further, examples of organic solvents include hydrocarbon organic solvents, such as aliphatic hydrocarbon organic solvents having 15 or less carbon atoms, such as n-hexane, 2-methylpentane, n-heptane, n-octane, 2,2,3-trimethylpentane, 2,2,4-trimethylpentane, n-nonane, 2,2,5-trimethylhexane, decane, dodecane, and pentadecane; aliphatic hydrocarbon organic solvents having 15 or more carbon atoms, such as henicosane, docosane, tetracosane, pentacosane, and nonacosane; alicyclic hydrocarbon organic solvents, such as cyclohexane, cyclooctane, cyclodecane, and cyclododecane; and aromatic hydrocarbon organic solvents, such as xylene, ethylbenzene, trimethylbenzene, isopropylbenzene, butylbenzene, diethylbenzene, pentylbenzene, dipentylbenzene, cyclohexylbenzene, naphthalene, tetralin, and biphenyl. These organic solvents may be used alone or in combination of two or more.

[0072] Among these, from the viewpoint of improving the peelability of protective tapes such as masking tapes from the surface coating composition of the curable composition, it is preferable that the organic solvent contains a hydrocarbon organic solvent having a boiling point (initial boiling point) of 150° C. or more, and it is particularly preferable that it contains a hydrocarbon organic solvent having a boiling point (initial boiling point) of 150° C. or more and 300° C. or less. Furthermore, from the viewpoint of improving the peelability of protective tapes such as masking tapes from the surface coating composition of the curable composition, it is preferable that the amount of hydrocarbon organic solvent having a boiling point (initial boiling point) of 150° C. or more in the organic solvent is 5 to 70 mass% (i.e., 5 to 70 mass% of hydrocarbon organic solvents having a boiling point (initial boiling point) of 150° C. or more and 30 to 95 mass% of organic solvents having a boiling point (initial boiling point) of less than 150° C.) from the viewpoint of further improving the peelability of protective tapes such as masking tapes from the surface coating composition of the curable composition. It is more preferable that the solvent contains 10 to 60 mass% of hydrocarbon organic solvents with a boiling point (initial boiling point) of 150°C or higher (i.e., 10 to 60 mass% of hydrocarbon organic solvents with a boiling point (initial boiling point) of 150°C or higher and 40 to 90 mass% of organic solvents with a boiling point (initial boiling point) of less than 150°C), and it is particularly preferable that the solvent contains 15 to 45 mass% of hydrocarbon organic solvents with a boiling point (initial boiling point) of 150°C or higher (i.e., 15 to 45 mass% of hydrocarbon organic solvents with a boiling point (initial boiling point) of 150°C or higher and 55 to 85 mass% of organic solvents with a boiling point (initial boiling point) of less than 150°C).

[0073] As the hydrocarbon organic solvent having a boiling point (initial boiling point) of 150° C. or higher, an aliphatic hydrocarbon organic solvent or an alicyclic hydrocarbon organic solvent is preferred.

[0074] As the organic solvent having a boiling point (initial boiling point) of less than 150°C, ester-based organic solvents such as ethyl acetate, ketone-based organic solvents such as methyl ethyl ketone, and acetate-based organic solvents such as ethylene glycol monomethyl ether acetate are preferred.

[0075] The amount of organic solvent in the surface coating composition is not particularly limited, but from the viewpoint of optimizing the coatability (applicability or sprayability) of the surface coating composition and the drying properties of the cured film of the surface coating composition, it is preferably 30 to 99 mass %, and particularly preferably 50 to 95 mass %.

[0076] <Modified organic isocyanate compound (optional component)> The surface coating composition of the present invention may contain, as an optional component, a modified organic isocyanate compound, as needed, within the scope of not impairing the object of the present invention. When the surface coating composition of the present invention further contains a modified organic isocyanate compound, the formability of the cured film of the surface coating composition is improved, and stickiness of the surface of the curable composition can be reduced. Examples of modified organic isocyanate compounds include those similar to the modified organic polyisocyanates that can be used in the production of the above-mentioned isocyanate group-containing urethane prepolymer and isocyanate group-containing (meth)acrylic urethane prepolymer. The incorporation of the modified organic isocyanate compound can be carried out in the same manner as in the production of the above-mentioned isocyanate group-containing urethane prepolymer and isocyanate group-containing (meth)acrylic urethane prepolymer. The modified organic polyisocyanate may be contained as an unreacted modified organic polyisocyanate, or the modified organic isocyanate compound may be blended when preparing the surface coating agent composition of the present invention.

[0077] Among the modified organic isocyanate compounds, from the viewpoint of improving the weather resistance of the surface coating agent composition, modified organic isocyanate compounds containing at least one of modified aliphatic polyisocyanates, modified araliphatic polyisocyanates, and modified alicyclic polyisocyanates are preferred. Furthermore, as the modified organic isocyanate compound, modified organic isocyanate compounds having an isocyanurate bond are preferred.

[0078] The amount of the modified organic isocyanate compound blended in the surface coating composition is preferably 1 to 20% by mass, particularly preferably 2 to 15% by mass. In addition, when an unreacted modified organic polyisocyanate remains as the modified organic isocyanate compound during the production of the isocyanate group-containing urethane prepolymer and the isocyanate group-containing (meth)acrylic urethane prepolymer, the blending amount is calculated as the total amount including the modified organic isocyanate compound blended as an optional component during the production of the surface coating composition.

[0079] <Matte agent (optional ingredient)> The surface coating agent composition of the present invention can contain a matting agent as an optional component, if necessary. When the surface coating agent composition of the present invention further contains a matting agent, it can contribute to imparting excellent matte properties to the surface of the curable composition.

[0080] The matting agent may be, for example, a particulate component. Examples of the material for the matting agent include polyolefins such as polyethylene and polypropylene, oxidized polyolefins, and silica. Alternatively, the matting agent may be one in which the matting component is dispersed in an organic solvent.

[0081] The average particle size of the matting agent is preferably 0.5 to 10 μm, particularly preferably 1 to 8 μm, from the viewpoint of contributing to imparting excellent matte properties to the surface of the curable composition. The average particle size in the present invention is the numerical value of the median diameter (d50) of the volume-based particle size distribution measured by a laser diffraction scattering method.

[0082] The amount of the matting agent in the surface coating composition is not particularly limited as long as it can impart matte properties to the surface of the curable composition. However, from the viewpoint of contributing to imparting excellent matte properties to the surface of the curable composition without impairing the coatability of the surface coating composition, the amount is preferably 0.5 to 10 mass %, and particularly preferably 1 to 5 mass %, relative to the total amount of (A) the isocyanate group-containing urethane resin and (B) the isocyanate group-containing (meth)acrylic urethane resin.

[0083] <Additives (optional ingredients)> The surface coating composition of the present invention can contain various additives as optional components, as long as the object of the present invention is not impaired. The additives are added to the surface coating composition to improve various properties of the surface coating composition, such as curing acceleration, weather resistance, adhesion, and defoaming. Specific examples of the additives include curing acceleration catalysts, weather stabilizers, adhesion promoters, and defoamers. These additives may be used alone or in combination of two or more.

[0084] The curing-accelerating catalyst is blended to promote the formation of a cured film by crosslinking and curing the surface coating agent composition of the present invention through reaction with an active hydrogen-containing compound (for example, water such as humidity). As the curing-accelerating catalyst, the same reaction catalysts as those used in the production of the above-mentioned (A) isocyanate group-containing urethane resin and (B) isocyanate group-containing (meth)acrylic urethane resin can be used. Note that when the curing-accelerating catalyst is used in the production of the above-mentioned (A) isocyanate group-containing urethane resin and (B) isocyanate group-containing (meth)acrylic urethane resin, When used as a reaction catalyst in the production of the hydroxyl group-containing (meth)acrylic urethane resin, the reaction catalyst remaining therein may act as a curing-accelerating catalyst for the surface coating composition.

[0085] The amount of the curing-accelerating catalyst in the surface coating composition is preferably 0.01 to 1 mass %, particularly preferably 0.05 to 0.5 mass %, based on the total amount of (A) isocyanate group-containing urethane resin and (B) isocyanate group-containing (meth)acrylic urethane resin.

[0086] The weather resistance stabilizer is added to prevent oxidation, light degradation, and heat degradation of the cured film (coating film) after applying or spraying the surface coating composition, thereby further improving weather resistance and heat resistance. Examples of the weather resistance stabilizer include hindered amine light stabilizers, hindered phenol antioxidants, and ultraviolet absorbers. These weather resistance stabilizers may be used alone or in combination of two or more.

[0087] Examples of the hindered amine light stabilizer include bis(2,2,6,6-tetramethyl-4-piperidyl)sebacate, decanedioic acid bis(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]butylmalonate, methyl 1,2,2,6,6-pentamethyl-4-piperidylsebacate, bis(1,2,2,6,6-pentamethyl-4-piperidyl)sebacate, 1-[2-[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyloxy]ethyl]-4-[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyloxy]-2,2,6,6 -tetramethylpiperidine, 4-benzoyloxy-2,2,6,6-tetramethylpiperidine, dimethyl succinate·1-(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 condensate, and ADEKA STAB LA-63P and LA-68LD manufactured by ADEKA Corporation.

[0088] Examples of hindered phenol antioxidants include pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 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(1,1-dimethylethyl)-4-hydroxy C7-C9 side chain alkyl ester, and 2,4-dimethyl-6-(1-methylpentadecyl)phenol.

[0089] Examples of the ultraviolet absorber include benzotriazole-based ultraviolet absorbers such as 2-(3,5-di-tert-butyl-2-hydroxyphenyl)-5-chlorobenzotriazole; triazine-based ultraviolet absorbers such as 2-(4,6-diphenyl-1,3,5-triazin-2-yl)-5-[(hexyl)oxy]phenol; benzophenone-based ultraviolet absorbers such as octabenzone; and benzoate-based ultraviolet absorbers such as 2,4-di-tert-butylphenyl-3,5-di-tert-butyl-4-hydroxybenzoate.

[0090] Among the above-mentioned weather resistance stabilizers, hindered amine-based light stabilizers and hindered phenol-based antioxidants are preferred because they have a higher effect of improving weather resistance. The amount of weather resistance stabilizer to be blended is determined by the ratio of (A) isocyanate group-containing urethane resin and (B) isocyanate group-containing (meth)acrylic urea resin. The content is preferably 0.1 to 5 mass %, particularly preferably 0.5 to 3 mass %, based on the total amount of the tungsten resins.

[0091] The adhesion promoter is blended to improve the adhesion between the surface coating composition and the curable composition, and the adhesion between the surface coating composition and the topcoat paint. Examples of the adhesion promoter include an epoxy silane coupling agent and a (meth)acrylic coupling agent. These adhesion promoters may be used alone or in combination.

[0092] Examples of epoxy silane coupling agents include 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, and 3-glycidoxypropyltriethoxysilane. Examples of (meth)acrylic coupling agents include 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, and 3-acryloxypropyltrimethoxysilane.

[0093] The amount of the adhesion promoter in the surface coating composition is preferably 0.1 to 5 mass %, particularly preferably 0.5 to 3 mass %, based on the total amount of (A) isocyanate group-containing urethane resin and (B) isocyanate group-containing (meth)acrylic urethane resin.

[0094] The antifoaming agent is blended to reduce foaming that occurs when the surface coating agent composition is applied or sprayed. Examples of the antifoaming agent include silicone-based antifoaming agents, fatty acid ester-based antifoaming agents, higher alcohol-based antifoaming agents such as aliphatic alcohol-based antifoaming agents having 6 or more carbon atoms, and polyether-based antifoaming agents. These antifoaming agents may be used alone or in combination of two or more.

[0095] The amount of the antifoaming agent blended in the surface coating composition is preferably 0.1 to 3 mass %, particularly preferably 0.2 to 2 mass %, based on the total mass of the surface coating composition.

[0096] The method for producing the surface coating agent composition of the present invention is not particularly limited and can be carried out by a known method. Specifically, the surface coating agent composition of the present invention can be produced by charging (A) an isocyanate group-containing urethane resin, (B) an isocyanate group-containing (meth)acrylic urethane resin, (C) an organic solvent, and, if necessary, a modified organic isocyanate compound, a matting agent, and additives into a mixing vessel equipped with a stirrer made of glass, stainless steel, iron, etc., and stirring and mixing them under a stream of inert gas such as nitrogen.

[0097] The curable composition to which the surface coating composition of the present invention is applied or sprayed will now be described. Specific examples of the curable composition include a curable composition containing a resin that cures upon reaction with an active hydrogen-containing compound.

[0098] Specific examples of the curable composition include silicone-based curable compositions, modified silicone-based curable compositions, polyurethane-based curable compositions, and polysulfide-based curable compositions. Among these, modified silicone-based curable compositions, polyurethane-based curable compositions, and polysulfide-based curable compositions are preferred, as they have an excellent balance of physical properties such as modulus, elongation, and tensile strength after curing, and modified silicone-based curable compositions and polyurethane-based curable compositions are particularly preferred.

[0099] These curable compositions include one-component moisture-curable compositions that cure by reacting with moisture in the air, and two-component reactive curable compositions that cure by reacting the base agent with the curing agent. The surface coating composition of the present invention can be used as either a one-component moisture-curable composition or a two-component reactive-curable composition.

[0100] One-component moisture-curable compositions often cure more slowly than two-component reactive curable compositions, and therefore their surfaces become sticky during curing, making them susceptible to contamination due to the adhesion of dust and dirt. When the surface coating composition of the present invention is applied or sprayed onto the surface of a one-component moisture-curable composition, a cured film can be formed on the surface of the curable composition, reducing the stickiness of the surface of the curable composition, making it particularly useful for preventing contamination of the surface of the curable composition.

[0101] The application method for forming a cured film on the surface of a curable composition by applying or spraying the surface coating agent composition of the present invention onto the surface of the curable composition will be described below.

[0102] First, the curable composition is poured or applied to a surface to be adhered, such as a base or a joint. Before pouring or applying the curable composition to the surface to be adhered, a primer may be applied to the surface to be adhered in advance to improve adhesion to the surface to be adhered. When a primer is applied, the composition is allowed to cure for a predetermined time until the primer dries and hardens.

[0103] After casting or applying the curable composition, the surface of the curable composition is smoothed using a spatula, roller, or the like to achieve the desired shape. When casting or applying the curable composition, a protective tape (masking tape) or a protective sheet (polymer masker) may be used as needed to prevent the curable composition from adhering to areas other than the surface to be adhered. Next, the surface coating composition of the present invention is applied or sprayed (sprayed) onto the surface of the curable composition. After applying or spraying (spraying) the surface coating composition, the protective tape or protective sheet is removed before a cured film is formed. Examples of tools for applying the surface coating composition include a brush and a spatula. Examples of tools for spraying (spraying) the surface coating composition include a spray gun, an airbrush, and an aerosol spray. The amount of application of the surface coating composition is not particularly limited as long as it does not impair the object of the present invention, but is preferably 10 to 100 g / m 2 is preferable, and 20 to 80 g / m 2 is particularly preferred.

[0104] When using an aerosol spray as a tool for spraying (spraying) the surface coating composition, known liquefied gas propellants or compressed gas propellants can be used as the propellant. Examples of liquefied gas propellants include LPG (liquefied petroleum gas) such as propane and butane, and alternative chlorofluorocarbon gases such as dimethyl ether (DME), HFC134a, HFC152a, and HF01234Ze. Examples of compressed gas propellants include nitrogen gas, carbon dioxide gas, and nitrous oxide gas. Among these, LPG and dimethyl ether (DME) are preferred for their convenience.

[0105] The curable composition to which the surface coating agent composition of the present invention can be applied specifically includes, for example, curable compositions used as sealants, waterproofing materials, coating materials, and is suitable as the surface coating agent composition of the curable composition used as sealing materials, waterproofing materials, coating materials for construction or civil engineering.Among these, the curable composition used as a sealant is preferred, the curable composition used as a sealant used in the joint (joint) between components is more preferred, the curable composition used as a sealant used in the joint (joint) between outdoor components is even more preferred, and the curable composition used as a sealant for the working joint, which is the joint (joint) that expands and contracts outdoors, is particularly preferred. [Example]

[0106] The present invention will be described in more detail below with reference to examples, but the present invention should not be construed as being limited to these.

[0107] [Synthesis Example 1] (Isocyanate group-containing urethane resin solution a-1) A reactor equipped with a stirrer, thermometer, nitrogen seal tube, and heating / cooling device was charged with 572.8 g of ethyl acetate and 257.4 g of isophorone diisocyanate (IPDI, molecular weight 222.2, Evonik Japan Co., Ltd.) while flowing nitrogen gas. While stirring, 122.1 g of polyoxypropylene triol with a number-average molecular weight of 300 and 3.8 g of dibutyltin dilaurate diluted 10 times with ethyl acetate as a reaction catalyst were added. The mixture was heated to 70-80°C and reacted for 1 hour, then cooled to room temperature to synthesize isocyanate-containing urethane resin solution a-1. The molar ratio (isocyanate groups / hydroxyl groups) of the isocyanate groups of isophorone diisocyanate (IPDI) to the hydroxyl groups (active hydrogens) of the polyoxypropylene triol was 1.9. The resulting isocyanate group-containing urethane resin solution a-1 had a theoretical resin content of 39.7% by mass and an isocyanate group content of 4.8% by mass as determined by titration.

[0108] [Synthesis Example 2] (Isocyanate group-containing urethane resin solution a-2) While flowing nitrogen gas, 136.4 g of ethyl acetate and 86.9 g of a mixed isocyanurate trimer of hexamethylene diisocyanate (HDI) and toluene diisocyanate (TDI) (Desmodur HL, isocyanate group content 10.5 mass%, solids content 60%, butyl acetate solution, manufactured by Bayer) were charged into a reaction vessel equipped with a stirrer, thermometer, nitrogen seal tube, and heating / cooling device, and 7.7 g of N-phenyl-γ-aminopropyltrimethoxysilane (KBM-573, manufactured by Shin-Etsu Chemical Co., Ltd.) was further charged while stirring. The mixture was heated to 70-80°C and reacted for 1 hour, and then cooled to room temperature to synthesize isocyanate group-containing urethane resin solution a-2. The molar ratio (isocyanate group / secondary amino group) of the isocyanate group of the mixed isocyanurate trimer of hexamethylene diisocyanate (HDI) and toluene diisocyanate (TDI) to the secondary amino group (active hydrogen) of N-phenyl-γ-aminopropyltrimethoxysilane was 7.2. Therefore, the isocyanate group-containing urethane resin solution a-2 contained unreacted mixed isocyanurate trimer of hexamethylene diisocyanate (HDI) and toluene diisocyanate (TDI). The resulting isocyanate group-containing urethane resin solution a-2 had a theoretical resin content of 25.9% by mass and an isocyanate group content of 3.4% by mass as determined by titration.

[0109] [Preparation Example 1] Isocyanate group-containing urethane resin solution While flowing nitrogen gas into a reaction vessel equipped with a stirrer, thermometer, nitrogen seal tube, and heating / cooling device, 300.0 g of isocyanate group-containing urethane resin solution a-1 obtained in Synthesis Example 1 and 72.5 g of isocyanate group-containing urethane resin solution a-2 obtained in Synthesis Example 2 were charged and stirred at room temperature for 1 hour to obtain an isocyanate group-containing urethane resin solution. The theoretical nonvolatile content of the isocyanate group-containing urethane resin solution was 37.0 mass%, and the isocyanate group content by titration was 4.5 mass%.

[0110] [Example 1] A reaction vessel equipped with a stirrer, a thermometer, a nitrogen seal tube, and a heating / cooling device was charged with 320.0 g of ethyl acetate, 215.0 g of a hydrocarbon organic solvent (Exxol D110, naphthenic, initial boiling point 248°C, dry point 265°C, manufactured by ExxonMobil Corporation), 135.0 g of the isocyanate group-containing urethane resin obtained in Preparation Example 1, and an isocyanate group-containing acrylic urethane resin (SM-4, solids content 59% by mass, solvent ethylbenzene:xylene 5%) while nitrogen gas was flowing into the reaction vessel. A 0:50 solvent, 150.0 g of an isocyanate group-containing acrylic urethane resin (manufactured by Asia Kogyo Co., Ltd.) with an NCO content of 3.2% by mass, a number average molecular weight of 1,195, a weight average molecular weight of 14,638, and an organic isocyanate compound pendant on the acrylic main chain, and 180.0 g of CE-10BE (10% by mass of polyethylene particles with an average particle size of 3 to 4 μm, 60% by mass of butyl acetate, 30% by mass of ethyl acetate, manufactured by Koyo Chemical Co., Ltd.) as a matting agent were charged, and the mixture was stirred at room temperature for 1 hour. The mixture was stirred to prepare a surface coating composition of the curable composition.

[0111] [Example 2] A surface coating composition of a curable composition was prepared in the same manner as in Example 1, except that 375.0 g of ethyl acetate and 160.0 g of the hydrocarbon organic solvent were used.

[0112] [Comparative Example 1] A surface coating composition of a curable composition was prepared in the same manner as in Example 1, except that the isocyanate group-containing urethane resin solution was not used.

[0113] Comparative Example 2 A surface coating composition of a curable composition was prepared in the same manner as in Example 1, except that the isocyanate group-containing acrylic urethane resin solution was not used.

[0114] Comparative Example 3 Comparative Example 3 was a case where no surface coating agent composition of the curable composition was used.

[0115] 180 g of the surface coating agent composition of the curable composition of Examples 1 to 2 and Comparative Examples 1 to 2 and 120 g of dimethyl ether were charged into an aerosol can and sealed under pressure. In each evaluation test, a coating amount of about 40 g / m was applied to the surface of the curable composition using the aerosol can. 2 It was spray coated with.

[0116] [Stain prevention (black silica sand stain prevention)] A 20mm x 100mm square frame was created on a slate board using a 10mm thick corner backer, and a curable composition (Auton Siding Sealant, a one-component moisture-curing polyurethane sealant composition, manufactured by Auto Chemical Industry Co., Ltd.) was poured into the frame, and the surface was smoothed flat with a spatula. Next, the surface coating compositions of Examples 1-2 and Comparative Examples 1-2 were applied to the surface of the curable composition, and the composition was cured for 3 hours under the following temperature and humidity conditions: 5°C, 40% RH, 23°C, 50% RH, and 35°C, 70% RH. After curing, black silica sand (8 Black, manufactured by K-Mu Viewcera) was applied to the surface of the curable composition at a rate of approximately 250g / m 2 After sprinkling in an amount of coating, the test specimen was placed upright so that the surface of the curable composition was vertical, and the black silica sand adhering to the surface of the curable composition was brushed off with a No. 5 brush. The state of adhesion of the black silica sand to the surface of the curable composition was visually confirmed and evaluated according to the following criteria. Note that, because the curable composition was in an uncured state, the black silica sand was brushed off slowly with the No. 5 brush so as not to deform the surface of the curable composition. Evaluation criteria ◎: Black silica sand does not adhere to the surface of the curable composition, and the surface of the curable composition is not contaminated ◯: A small amount of black silica sand adheres to the surface of the curable composition, and the surface of the curable composition is slightly contaminated. ×: A large amount of black silica sand adheres to the surface of the curable composition, contaminating the surface of the curable composition.

[0117] [Anti-pollution properties (anti-pollution properties from raindrops)] Two aluminum angles (12 mm wide x 150 mm long x 12 mm deep) were fixed on an aluminum plate in a V-shape (the distance between the aluminum angles was 2 mm at one end and 12 mm at the other end). This was designated as test piece A. A curable composition (Auton Siding Sealant, a one-component moisture-curing polyurethane sealant composition, manufactured by Auto Chemical Industries Co., Ltd.) was poured into the frame of an aluminum channel (width 22 mm × length 150 mm × depth 13 mm), and the surface was smoothed flat with a spatula. The surface of the curable composition was then coated with the surface coating compositions of Examples 1 and 2 and Comparative Examples 1 and 2. This was designated test piece part B. The test piece was placed so that there was no difference in level between the surface of test piece A and the surface of the curable composition of test piece B, and the end (2 mm side) of the V-shaped part formed by the aluminum angle of test piece A and test piece B Both parts were fixed so that the midpoints of the long sides of the aluminum channel were in contact, and the aluminum angle part was placed vertically outdoors on top. Three months after installation, the adhesion of sand and dust to the surface of the curable composition was visually inspected and evaluated according to the following criteria. Evaluation criteria ◎: Almost no dirt such as sand or dust adheres to the surface of the curable composition ○: A small amount of dirt such as sand and dust is attached to the surface of the curable composition. ×: A lot of dirt such as sand and dust adheres to the surface of the curable composition, damaging the appearance.

[0118] [Masking tape peelability] Two sheets of siding (Neolock Hikaricera 18, manufactured by Kemi Corporation) were attached parallel to a slate board, creating a joint measuring 10 mm wide x 100 mm long x 10 mm deep. Masking tape was applied to the surface of the siding along the joint edge, and then a curable composition (Auton Siding Sealant, a one-component moisture-curing polyurethane sealant composition manufactured by Auto Chemical Industries Co., Ltd.) was poured into the joint and the surface was smoothed flat with a spatula. Next, the surface coating compositions of Examples 1-2 and Comparative Examples 1-2 were applied to the surface of the curable composition and the masking tape, and the resulting mixture was cured for 10 minutes at a temperature and humidity of 35°C and 70% RH. After curing, the masking tape was peeled off the siding, and visual observation was performed to determine whether stringiness or burrs were present due to the cured coating film of the surface coating composition. Evaluation was based on the following criteria. Evaluation criteria ○: No stringing or burrs due to the cured coating, and the joints and edges are clean △: The hardened coating film causes some stringiness and burrs, and some burrs remain at the joint edges, but the joints are clean. ×: Stringiness and burrs are generated by the cured coating, and the joints and joint edges are visible due to the cured coating.

[0119] [Matte finish] A 20mm x 70mm square frame was created on a slate board using a 10mm thick corner backer, and a curable composition (Auton Siding Sealant, a one-component moisture-curing polyurethane sealant composition, manufactured by Auto Chemical Industry Co., Ltd.) was poured into the frame, and the surface was smoothed flat with a spatula. Next, the surface coating compositions of Examples 1-2 and Comparative Examples 1-2 were applied to the surface of the curable composition, and the composition was cured for 7 days under temperature and humidity conditions of 23°C and 50% RH. The gloss state of the surface of the curable composition was visually confirmed and evaluated according to the following criteria. Evaluation criteria ○: The gloss has disappeared ×: The gloss has not faded

[0120] [Stretchability (dynamic exposure)] A dynamic exposure tester with the following specifications was installed outdoors facing south and used for the test. One piece of siding (Excellage Hydrophilic 14, manufactured by Kemi Corporation) was fixed to each of the fixed and movable jigs of the tester, facing each other, so that the movement of the tester was transmitted to the joints made by the siding. After installing 10 mm thick corner backers into the joints, a one-component urethane primer composition (OP-2020, manufactured by Auto Chemical Industry Co., Ltd.) was applied to the joint-covered surface of the siding and allowed to dry and harden. A curable composition (Auton Siding Sealant, a one-component moisture-curing polyurethane sealant composition, manufactured by Auto Chemical Industry Co., Ltd.) was poured into the joints, and the surface was smoothed with a spatula. The surface of the curable composition was immediately coated with the surface coating compositions of Examples 1-2 and Comparative Examples 1-2. The appearance of the curable composition was visually observed 24 hours after application and evaluated according to the following criteria. The maximum displacement within 24 hours after application was 1.0 mm. Dynamic Exposure Tester Specifications Mounting angle: 30 degrees Movement generating unit: Black acrylic resin plate (length 2,000mm x width 500mm x thickness 40mm) Fixed and movable beams: Aluminum (length 500mm x width 50mm x thickness 50mm) Measuring instruments: Expansion detector, temperature detector Recording device: dot recorder Evaluation criteria 〇: No wrinkles or cracks are found in the joints △: Wrinkles are observed in the joints, but no cracks are observed ×: Wrinkles and cracks are observed in the joints

[0121] [Elasticity (repeated stretch)] Two pieces of siding (Excellage Hydrophilic 14, manufactured by Kemi Corporation) and corner backing were placed on a slate board to create a 10 mm wide x 50 mm long x 10 mm deep joint. A one-component urethane primer composition (OP-2020, manufactured by Auto Chemical Industry Co., Ltd.) was applied to the joint-covered surfaces of the siding and allowed to dry and harden. After that, a curable composition (Auton Siding Sealant, a one-component moisture-curing polyurethane sealant composition, manufactured by Auto Chemical Industry Co., Ltd.) was poured into the joint and smoothed flat with a spatula. Next, the surface coating compositions of Examples 1-2 and Comparative Examples 1-2 were applied to the surface of the curable composition and cured for 14 days at a temperature and humidity of 23°C and 50% RH, followed by another 14 days at a temperature of 30°C. These specimens were used as test specimens. The test specimen was immediately placed in a repeating test machine (special type sealant fatigue test machine, manufactured by Toyo Seiki Co., Ltd.), and the test machine was set so that the displacement width was ±20% (±2 mm) of the joint width, and the expansion and contraction cycle was performed 2,000 times. After 2,000 cycles, the joint surface was visually inspected for wrinkles and cracks and evaluated according to the following criteria. Evaluation criteria 〇: No wrinkles or cracks are found on the joint surface ×: Wrinkles or cracks are observed on the joint surface.

[0122] [Topcoat paint adhesion] A 50mm x 50mm square frame was made on a slate board using a 10mm thick corner backer, and a curable composition (Auton Siding Sealant, a one-component moisture-curing polyurethane sealant composition, manufactured by Auto Chemical Industry Co., Ltd.) was poured into the frame, and the surface was smoothed flat with a spatula. Next, the surface coating compositions of Examples 1-2 and Comparative Examples 1-2 were applied to the surface of the curable composition, and after curing for 3 days under temperature and humidity conditions of 23°C and 50% RH, water-based paint A (primer: water-based Mylacealer Eco (manufactured by SK Chemical Co., Ltd.) at approximately 120g / m2) was applied to the surface of the curable composition. 2 Allow to cure for 3 hours after application. Top coat: Water-based Ceramic Silicone (SK Chemical Co., Ltd.) approx. 280g / m 2 Application), or water-based paint B (primer: Hybrid Sealer EPO (SK Chemical Co., Ltd.) approx. 150 g / m 2 Allow to cure for 3 hours after application. Top coat: Water-based Ceramic Silicone (SK Chemical Co., Ltd.) approx. 280g / m 2 The top coat (coating) was applied and cured for 7 days at a temperature and humidity of 23°C and 50% RH. After curing, a grid pattern (25 squares) was cut into the top coat (coating film) with a cutter, and cellophane tape was applied to the surface of the top coat (coating film). After peeling off the cellophane tape, the number of squares (maximum 25 squares) of top coat (coating film) remaining on the sealant was visually confirmed.

[0123] The compositions and evaluation results of the surface coating compositions of Examples 1 and 2 and Comparative Examples 1 and 2 are shown in Table 1 below.

[0124] [Table 1]

[0125] From the results in Table 1 above, it was found that the surface coating compositions of Examples 1 and 2 were excellent in stain resistance (black silica sand stain resistance, raindrop stain resistance), matte finish, and stretchability (dynamic exposure, repeated stretching), and also had excellent masking tape peelability and topcoat paint adhesion.

[0126] On the other hand, in Comparative Example 1, which did not use (A) isocyanate group-containing urethane resin, and Comparative Example 2, which did not use (B) isocyanate group-containing (meth)acrylic urethane resin, stain resistance (black silica sand stain resistance) was not obtained. Furthermore, in Comparative Example 1, masking tape peelability was not obtained, and in Comparative Example 2, raindrop stain resistance and stretch test (dynamic exposure) were not obtained. Furthermore, in Comparative Example 3, which did not use a surface coating agent composition of a curable composition, stain resistance (black silica sand stain resistance and raindrop stain resistance) and matte finish were not obtained. [Industrial Applicability]

[0127] The surface coating agent composition of the curable composition of the present invention has excellent stretchability and can impart excellent stain resistance and matte properties to the surface of the curable composition, and can be suitably used for construction and civil engineering purposes.

Claims

1. A surface coating agent composition of a curable composition, comprising (A) an isocyanate group-containing urethane resin, (B) an isocyanate group-containing (meth)acrylic urethane resin, and (C) an organic solvent.

2. the (A) isocyanate group-containing urethane resin is a reaction product of an organic isocyanate compound and an active hydrogen-containing compound that does not contain an isocyanate group-reactive functional group-containing (meth)acrylic resin, The surface coating agent composition of the curable composition according to claim 1, characterized in that the (B) isocyanate group-containing (meth)acrylic urethane resin is a reaction product of an organic isocyanate compound and an active hydrogen-containing compound including an isocyanate group-reactive functional group-containing (meth)acrylic resin.

3. 3. The surface coating agent composition of claim 2, wherein the active hydrogen-containing compound that does not contain an isocyanate group-reactive functional group-containing (meth)acrylic resin is one or more active hydrogen-containing compounds selected from the group consisting of high molecular weight polyols with a number average molecular weight of 1,000 or more, high molecular weight monools with a number average molecular weight of 1,000 or more, low molecular weight polyols with a number average molecular weight of less than 1,000, low molecular weight monools with a number average molecular weight of less than 1,000, and isocyanate group-reactive functional group-containing silane compounds (excluding isocyanate group-reactive functional group-containing (meth)acrylic resins).

4. 3. The surface coating agent composition of the curable composition according to claim 1, wherein the (B) isocyanate group-containing (meth)acrylic urethane resin is a resin in which an organic isocyanate compound is pendant on an active hydrogen-containing compound including an isocyanate group-reactive functional group-containing (meth)acrylic resin.

5. The isocyanate group-reactive functional group is selected from the group consisting of —COOH, —OH, and —NH ２ 3. The surface coating agent composition of claim 2, wherein the functional group is one or more selected from the group consisting of —NH and —SH.

6. The surface coating agent composition of the curable composition according to claim 1 or 2, characterized in that a blending ratio of the isocyanate group-containing urethane resin (A) to the isocyanate group-containing (meth)acrylic urethane resin (B) is 10 / 90 to 90 / 10, in terms of the number of moles of isocyanate groups in the isocyanate group-containing urethane resin (A) to the number of moles of isocyanate groups in the isocyanate group-containing (meth)acrylic urethane resin (B).

7. The surface coating agent composition of the curable composition according to claim 1 or 2, characterized in that the total amount of the (A) isocyanate group-containing urethane resin and the (B) isocyanate group-containing (meth)acrylic urethane resin is 1 to 70 mass% in the surface coating agent composition.

8. The surface coating agent composition of the curable composition according to claim 1 or 2, characterized in that the (C) organic solvent contains 5 to 70 mass % of a hydrocarbon organic solvent having a boiling point (initial boiling point) of 150°C or higher.

9. 3. The surface coating agent composition of the curable composition according to claim 1 or 2, further comprising a modified organic isocyanate compound having one or more bonds selected from the group consisting of a uretdione bond, an isocyanurate bond, an allophanate bond, a biuret bond, a uretonimine bond, a carbodiimide bond, a urethane bond, and a urea bond.

10. The curable composition according to claim 1 or 2, further comprising a matting agent. A surface coating composition.

11. The surface coating composition of a curable composition according to claim 10, wherein the matting agent is one or more matting agents selected from the group consisting of polyolefins, oxidized polyolefins, and silica.

12. A construction method characterized by applying or spraying a surface coating agent composition containing (A) an isocyanate group-containing urethane resin, (B) an isocyanate group-containing (meth)acrylic urethane resin, and (C) an organic solvent onto the surface of a curable composition, thereby forming a cured film on the surface of the curable composition.

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