JP7495617B2 - Construction sealant having a mottled pattern and its application method - Google Patents

Description

The present invention relates to a construction sealant having a mottled pattern and a method for applying the same.

Traditionally, the interior and exterior walls of buildings have generally been constructed of wall materials such as concrete, mortar, and siding boards, and architectural sealants (hereinafter sometimes referred to as "sealants") that are filled into the joints between the wall materials for the purpose of waterproofing and absorbing distortion caused by the expansion and contraction of the wall materials. In recent years, the number of buildings with excellent design has increased, and the designs of wall materials have become more diverse. There is a demand for the sealant surface to harmonize with the adjacent wall material surface without compromising the design of the wall material, giving the entire exterior wall a unified design.

There have been proposals to ensure that such sealants and wall materials are in harmony with each other in terms of design, and to improve the design of sealants. Patent Document 1 discloses a method in which a sealant is used in which a shapeless main sealant is mixed with a scale-like or granular material of a given size, and after filling the sealant into joints, the scale-like or granular material is rubbed with a spatula during surface finishing to bring it to the surface. This is said to improve the design compared to conventional sealants with a smooth surface.

Patent Document 2 describes a method for enhancing the design by using a surface finishing tape consisting of a tape body and fine substances detachably attached to the tape body, pressing the surface finishing tape against the uncured surface of an amorphous sealant, and adhering the fine substances so that they stand out on the surface of the sealant.

In addition, although it is not intended to harmonize the surfaces of such sealing materials and wall materials, a coating film forming method has been proposed that imparts design to a substrate or improves the design of the substrate. Patent Document 3 describes a method for forming a design coating film in which a water-based paint containing a water-based synthetic resin emulsion, a coloring pigment, a carbonate or sulfate as an extender pigment, and a urethane association thickener is applied to a substrate that already has an uneven surface and a color pattern, so that at least a part of the unevenness of the substrate can be recognized and the thickness is equal to or greater than the concealing thickness, to form a coating film, and while the coating film is still wet, a pattern roller having an uneven surface is used to form unevenness in at least a part of the coating film, and the coating film is changed to form a part of the coating film with a thickness equal to or less than the concealing thickness.

Patent Document 4 describes a method for forming a coating film, which includes the steps of: (1) applying intermediate coating paint (I) to at least a portion of a surface to be coated and drying the intermediate coating film so that the solid content of the intermediate coating film is less than 85% by mass; (2) applying intermediate coating paint (II) that forms a coating film with a color difference ΔE of 7 or more from the coating film of intermediate coating paint (I) to at least a portion of the coated plate obtained in step (1) using a pressing tool and drying the applied intermediate coating paint (II) to form a coating film with a gradated pattern; and (4) applying paint containing colored coating particles (III) to the coated plate having the gradated pattern coating obtained in step (2) and drying the applied intermediate coating paint.

Japanese Patent Application Laid-Open No. 9-53063 JP 2005-75974 A JP 2012-45520 A Patent No. 5748221

However, while the inventions described in Patent Documents 1 and 2 can form irregularities on the surface of the sealant, they cannot accommodate the recent diversification of wall materials. Furthermore, the inventions described in Patent Documents 3 and 4 have the following concerns: (a) complicated processes are required, lengthening the construction period; (b) it is difficult to select a paint suitable for the sealant material; and (c) if a paint unsuitable for the sealant material is used, the paint film may crack or peel off, or the paint film may become contaminated (for example, components contained in the sealant may migrate to the paint film, impairing the paint performance, or the surface may become sticky and dirty).

In recent years, wall materials that make the most of the texture of the material have been attracting attention, and the surface of such materials has a non-uniform pattern that is unique to the material and is a mixture of different colors and shades of the same color. There is a demand for a sealant that can be easily applied without compromising the texture of wall materials that contain such complex patterns and that can prevent cracking and peeling of the coating. However, the current situation is that the above-mentioned conventional technologies are unable to meet such market demands.

The object of the present invention is to provide a construction sealant that has a mottled pattern that harmonizes with wall materials on the surface, with a non-uniform pattern that is a mixture of different colors or shades of the same color, and that can suppress the occurrence of cracks and peeling of the coating, and also to provide a construction method that can easily form such a construction sealant.

The inventors of the present invention conducted extensive research to solve the above-mentioned problems. As a result, they discovered that the above-mentioned problems could be solved by incorporating a reactive polymer having a common functional group into the composition forming the sealant to be poured into the joints and the composition to be partially applied to the surface of the sealant, and by making the tensile breaking elongation of the cured product of the composition to be partially applied to the surface of the sealant 100% or more, and thus completed the present invention. The gist of the present invention is as follows.

(1) An architectural sealant, in which the surface of a cured product of an architectural sealant composition (I) containing an (A) reactive polymer, an (B) filler, and an (C) curing catalyst is partially covered with a cured product of a partial coating coating composition (II) containing a reactive polymer (A') having the same functional group as that contained in the reactive polymer (A), and which has a mottled pattern, and the cured product of the partial coating coating composition (II) has a tensile break elongation of 100% or more.
(2) The architectural sealant according to item (1), wherein the functional group contained in the reactive polymer (A) is a silyl group or an isocyanate group, and the main skeleton of the reactive polymer (A) contains a polyoxyalkylene skeleton and/or a (meth)acrylic acid ester skeleton.
(3) The architectural sealant according to the above item (1) or (2), wherein the surface area ratio of the cured product of the partial coating composition (II) that partially coats the surface of the cured product of the architectural sealant composition (I) is 10 to 70%.
(4) The architectural sealant according to any one of the above items (1) to (3), wherein the cured product of the architectural sealant composition (I) is disposed in a gap having a width of 5 to 30 mm between two or more ceramic siding boards.
(5) The architectural sealant according to the above item (4), wherein the surface of the ceramic siding board is formed with the same pattern as the mottled pattern.
(6) The architectural sealant according to any one of the above items (1) to (5), wherein the (II) partial coating composition contains the (A') reactive polymer, the (C') curing catalyst, and the (D') plasticizer.
(7) A method for applying an architectural sealant having a mottled pattern, in which the architectural sealant according to any one of items (1) to (6) is cast between wall materials, the method comprising the steps of: forming gaps at predetermined intervals between a plurality of wall materials and installing them in predetermined positions; pouring the architectural sealant composition (I) into the gaps, smoothing the surface and forming an undercoat layer; and curing the surface of the undercoat layer, and then applying the partial coating composition (II) in a mottled pattern.
(8) The method for applying the architectural sealant according to item (7) above, wherein the partial coating composition (II) is applied by spray coating or spread coating.
(9) The method for applying the architectural sealant according to item (7) or (8), wherein the surface curing time of the undercoat layer is 5 hours or less for curing to a thickness of 0.5 mm from the surface under conditions of 23° C. and a relative humidity of 50% RH.
(10) A set for forming an architectural sealant having a mottled pattern, comprising an architectural sealant composition (I) contained in a container (I) and a partial coating coating composition (II) contained in a container (II), wherein the architectural sealant composition (I) contains a reactive polymer (A), a filler (B) and a curing catalyst (C), the partial coating coating composition (II) contains a reactive polymer (A') having the same functional group as the functional group contained in the reactive polymer (A), and the cured product of the partial coating coating composition (II) has a tensile break elongation of 100% or more.
(11) The set for forming an architectural sealant having a mottled pattern according to item (10), wherein the time required for a surface layer portion of the architectural sealant composition (I) from the outer surface to 0.5 mm in the thickness direction to harden is 5 hours or less under conditions of 23°C and a relative humidity of 50% RH when the architectural sealant composition (I) is hardened.
(12) The set for forming an architectural sealant having a mottled pattern according to item (10) or (11), wherein the viscosity of the architectural sealant composition (I) and the partial coating composition (II) at a shear rate of 2.1 sec- ¹ is 200,000 to 5,000,000 mPa·s.
(13) The functional group contained in the reactive polymer (A) is at least one hydrolyzable silyl group selected from a trimethoxysilyl group and a dimethoxymethylsilyl group,
The set for forming an architectural sealant having a mottled pattern according to any one of items (10) to (12), wherein the (C) curing catalyst is a tetravalent tin-based catalyst, and the content thereof is 0.1 to 12% by mass relative to the (A) reactive polymer containing a hydrolyzable silyl group.
(14) The set for forming an architectural sealant having a mottled pattern according to any one of items (10) to (13), wherein the architectural sealant composition (I) contains a plasticizer (D), and the partial coating composition (II) contains a filler (B') and a plasticizer (D').

The present invention provides a construction sealant that has a mottled pattern that harmonizes with the wall material on the surface, with a non-uniform pattern that is a mixture of different colors or shades of the same color, and that can suppress the occurrence of cracks and peeling of the coating, and also provides a construction method that can easily form such a construction sealant.

FIG. 13 is a diagram showing an image of the surface of the construction sealant of Example 11 taken with an optical microscope. FIG. 13 is a diagram showing an image of the surface of the construction sealant of Example 12 taken with an optical microscope. FIG. 13 is an optical microscope image of the surface of the construction sealant of Example 13. FIG. 17 is a diagram showing an image of the surface of the construction sealant of Example 14 taken with an optical microscope. FIG. 17 is a diagram showing an image of the surface of the construction sealant of Example 15 taken with an optical microscope. FIG. 17 is a diagram showing an image of the surface of the architectural sealant of Example 16 taken with an optical microscope.

(Architectural sealant having a mottled pattern)
The architectural sealant according to the embodiment of the present invention has a mottled pattern formed by partially covering the surface of a cured product of (I) architectural sealant composition (hereinafter sometimes referred to as "composition (I)") with a cured product of (II) partial coating paint composition (hereinafter sometimes referred to as "composition (II)"). The architectural sealant composition (I) contains (A) a reactive polymer, (B) a filler, and (C) a curing catalyst, and the partial coating paint composition (II) contains (A') a reactive polymer having the same functional group as that contained in the reactive polymer (A). The cured product of composition (II) has a tensile elongation at break of 100% or more.

Here, "mottled" refers to a pattern that is a mixture of different colors or light and dark shades of the same color.

In this way, the reactive polymers contained in composition (II) and composition (I) have the same functional groups, and therefore the adhesiveness between the two is good. This results in the following effects: (a) it is possible to form a mottled pattern with suppressed peeling, and (b) as described below, composition (II) can be applied at the stage when the surface of composition (I) has hardened, thereby shortening the construction period. In addition, since the breaking elongation of the cured product of composition (II) is 100% or more, this, together with the good adhesiveness between compositions (I) and (II), makes it possible to more effectively suppress the occurrence of cracks and peeling of the coating film, and a sealant with excellent durability can be obtained.

The reactive polymer (A) contained in the composition (I) may be a reactive group-containing polymer having a reactive group used in a sealant. Examples of reactive groups include hydrolyzable silyl groups, isocyanate groups, epoxy groups, amino groups, and hydroxyl groups. Of these, hydrolyzable silyl groups and isocyanate groups are preferred from the standpoints of physical properties, workability, weather resistance, adhesion, curability, and the like.

(A) Examples of reactive polymers include reactive group-containing polyether polymers, reactive group-containing silicone polymers, reactive group-containing polyurethane polymers, reactive group-containing polysulfide polymers, reactive group-containing (meth)acrylic polymers, reactive group-containing polyisobutylene polymers, reactive group-containing rubber polymers such as SBR and butyl rubber, etc. These reactive polymers may be used alone or in combination of two or more.

Examples of hydrolyzable silyl group-containing polymers that contain hydrolyzable silyl groups as reactive groups include hydrolyzable silyl group-containing polyether polymers, hydrolyzable silyl group-containing silicone polymers, hydrolyzable silyl group-containing polyurethane polymers, hydrolyzable silyl group-containing polysulfide polymers, hydrolyzable silyl group-containing (meth)acrylic polymers, hydrolyzable silyl group-containing polyisobutylene polymers, and hydrolyzable silyl group-containing rubber polymers. Among these, hydrolyzable silyl group-containing polyether polymers (modified silicone), hydrolyzable silyl group-containing (meth)acrylic polymers, and hydrolyzable silyl group-containing polyisobutylene polymers are preferred, and hydrolyzable silyl group-containing polyether polymers (modified silicone) and hydrolyzable silyl group-containing (meth)acrylic polymers are more preferred.

The hydrolyzable silyl group is preferably an alkoxysilyl group, more preferably at least one selected from a dimethoxysilyl group, a trimethoxysilyl group, a diethoxysilyl group, and a triethoxysilyl group, and even more preferably at least one selected from a dimethoxysilyl group and a trimethoxysilyl group.

As the hydrolyzable silyl group-containing polyether polymer (modified silicone), those having a polyoxyalkylene ether as the main chain, i.e., those having a polyoxyalkylene skeleton as the main chain, are preferred, and those having hydrolyzable silyl groups at the end of the main chain and/or at the side chain, preferably at the end, are more preferred. In addition, the number of hydrolyzable silyl groups per molecule is preferably 1.2 or more.

The hydrolyzable silyl group-containing polyether polymer may contain a urethane bond in addition to the hydrolyzable silyl group. Examples of such polyether polymers include a polymer obtained by reacting a compound having active hydrogen and a hydrolyzable silyl group with an isocyanate-terminated polyether polymer, and a polymer obtained by reacting a polyether polymer with a silicon compound having an isocyanate group and a silyl group.

Examples of polyether-based polymers having reactive silyl groups include MS Polymer S203, S303, S810; SILYLEST250, EST280; SAT10, SAT200, SAT220, SAT350, SAT400 manufactured by Kaneka Corporation, EXCESTARS2410, S2420, or S3430 manufactured by AGC Corporation, and those described in Japanese Patent No. 5173364.

As the hydrolyzable silyl group-containing (meth)acrylic polymer, a polymer whose main chain is composed of at least (meth)acrylic acid ester structural units and has hydrolyzable silyl groups at the terminals and/or side chains is preferred. In addition to the (meth)acrylic acid ester units, the main chain may contain structural units derived from monomers that can be copolymerized with (meth)acrylic acid esters, such as olefins having 4 to 12 carbon atoms, vinyl ethers, aromatic vinyl compounds, vinyl silanes, and allyl silanes.

Examples of hydrolyzable silyl group-containing (meth)acrylic polymers include the following (i) and (ii):

(i) (a) acrylic acid alkyl esters (the number of carbon atoms in the alkyl group is preferably 2 to 4), such as ethyl acrylate, propyl acrylate, n-butyl acrylate, isobutyl acrylate, amyl acrylate, hexyl acrylate, 2-ethylhexyl acrylate, cyclohexyl acrylate, n-octyl acrylate, etc.; (b) vinyl alkoxysilanes, such as vinyl trimethoxysilane, vinyl methyl dimethoxysilane, vinyl triethoxysilane, vinyl dimethyl methoxysilane, etc., and (meth)acryloxyalkoxysilanes, such as γ-methacryloxypropyl trimethoxysilane, γ-methacryloxypropyl A polymer produced by radical copolymerization (usually using a known method such as bulk polymerization or solution polymerization using a polymerization initiator such as α,α'-azobisisobutyronitrile (AIBN), α,α'-azobisisovaleronitrile, benzoyl peroxide, or methyl ethyl ketone peroxide; or a redox polymerization method combining a redox catalyst such as a transition metal salt, an amine, or the like with a peroxide initiator) of one or a mixture of two or more selected from the group consisting of methyldimethoxysilane, etc., in the presence of (c) a mercaptoalkoxysilane as a chain transfer agent, such as γ-mercaptopropylmethyldimethoxysilane, γ-mercaptopropyltrimethoxysilane, etc. For example, the polymer disclosed in JP-B-3-80829.

(ii) (a) vinyl monomers, for example, acrylates such as ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, propyl acrylate, pentyl acrylate, stearyl acrylate, etc.; methacrylates such as methyl methacrylate, ethyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, lauryl methacrylate, benzyl methacrylate, cyclohexyl methacrylate, etc.; styrene or its derivatives (α-methylstyrene, chloromethylstyrene, etc.); fumaric acid diesters such as diethyl fumarate, dibutyl fumarate, dipropyl fumarate, etc.; vinyl halides such as vinyl chloride, vinylidene chloride, ethylene fluoride, vinylidene fluoride, vinylene fluoride, etc., 100 parts by mass of (b) an alkoxysilyl group-containing disulfide compound A compound such as 0.05 to 50 parts of bis(trimethoxysilylmethyl) disulfide, bis(triethoxysilylmethyl) disulfide, bis(trimethoxysilylpropyl) disulfide, bis(triethoxysilylpropyl) disulfide, bis(methyldimethoxysilylmethyl) disulfide, bis(methyldiethoxysilylmethyl) disulfide, bis(propyldimethoxysilylmethyl) disulfide, bis(propyldiethoxysilylmethyl) disulfide, bis(dimethylmethoxysilylpropyl) disulfide, or bis(dimethylethoxysilylpropyl) disulfide is added to the mixture, and photopolymerized (exposed to light at room temperature or 50 to 60°C for 4 to 30 hours) in an organic solvent (toluene, xylene, hexane, ethyl acetate, dioctyl phthalate, etc.) as necessary. For example, the polymer disclosed in JP-B-4-69667.

The hydrolyzable silyl group-containing polymer may be a mixture or reaction product of the above-mentioned hydrolyzable silyl group-containing polyether polymer and hydrolyzable silyl group-containing (meth)acrylic polymer. Representative commercially available products of such mixtures or reaction products include, for example, SA410, SB803S, MA903, S943, etc., manufactured by Kaneka Corporation, which are mixtures or reaction products of polyoxyalkylene polymers having alkoxysilyl groups and (meth)acrylic polymers having alkoxysilyl groups.

The weight average molecular weight of the hydrolyzable silyl group-containing polymer in terms of polystyrene may be 10,000 to 30,000, and preferably 15,000 to 28,000.

Examples of isocyanate group-containing polymers that contain isocyanate groups as reactive groups include terminal isocyanate group-containing urethane prepolymers (hereinafter sometimes referred to as "terminal NCO-containing prepolymers"), such as Pandex P870 and P910 manufactured by DIC.

NCO-terminated prepolymers can be obtained by reacting various polyols with an excess amount of a polyisocyanate compound (usually OH/NCO = 1/1.3 to 1/3.0).

Examples of polyols include polyether polyols obtained by addition polymerization of propylene oxide or alkylene oxides such as propylene oxide and ethylene oxide to polyhydric alcohols such as ethylene glycol, propylene glycol, glycerin, trimethylolpropane, pentaerythritol, sorbitol, and sucrose; ethylene glycol, propylene glycol, and their oligoglycols; butylene glycol, hexylene glycol, and polytetramethylene ether glycols; polycaprolactone polyols; polycarbonate polyols; polyester polyols such as polyethylene adipate; polybutadiene polyols; higher fatty acid esters having hydroxyl groups such as castor oil; and polymer polyols obtained by grafting vinyl monomers onto polyether polyols or polyester polyols. These may be used alone or in combination of two or more. Of these, those capable of forming a polyoxyalkylene skeleton are preferred.

As the polyisocyanate compound, for example, any one belonging to aromatic, aliphatic or alicyclic groups can be used. For example, tolylene diisocyanate (TDI; 2,4-isomer, 2,6-isomer and mixtures thereof), diphenylmethane diisocyanate (MDI), 3,3'-dimethyl-4,4'-biphenylene diisocyanate, 1,4-phenylene diisocyanate, xylylene diisocyanate, tetramethylxylylene diisocyanate, naphthylene diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, crude TDI, crude MDI, polymethylene polyphenyl isocyanate, isophorone diisocyanate, hexamethylene diisocyanate, and hydrogenated xylylene diisocyanate, as well as their isocyanurate, carbodiimide and biuret derivatives. These may be used alone or in combination of two or more.

The weight average molecular weight of the isocyanate group-containing polymer in terms of polystyrene may be 2,000 to 20,000, and preferably 3,000 to 10,000.

When an isocyanate group-containing polymer is used as the (A) reactive polymer, the isocyanate group-containing polymer can be used as a base component, and a polyol can be included as a curing agent component that crosslinks with the base component. The polyols used as the curing agent component can be those mentioned above. The polyol used as the curing component can be the same as or different from the one used in the synthesis of the NCO-terminated prepolymer.

Examples of the filler (B) contained in the composition (I) include inorganic salts such as heavy calcium carbonate, light calcium carbonate, fatty acid-treated calcium carbonate, colloidal calcium carbonate, fume silica, precipitated silica, carbon black, magnesium carbonate, diatomaceous earth, mica, talc, mica, clay, bentonite, organic bentonite, ferric oxide, and zinc oxide; balloons such as glass beads, shirasu balloons, glass balloons, silica balloons, and plastic balloons; inorganic fibers such as glass fibers and metal fibers; organic fibers such as polyethylene fibers and polypropylene fibers; and needle-shaped crystalline fillers such as aluminum borate, silicon carbide, silicon nitride, potassium titanate, graphite, needle-shaped crystalline calcium carbonate, magnesium borate, titanium diboride, chrysotile, and wollastonite. These may be used alone or in combination of two or more.

The curing catalyst (C) contained in the composition (I) can be appropriately selected taking into consideration the type of reactive polymer (A) and other factors. For example, in the case of a hydrolyzable silyl group-containing polymer, a tin metal catalyst or a non-tin metal catalyst can be used. Examples of the tin metal catalyst include tin carboxylates such as tin octylate, tin oleate, tin stearate, tin dioctylate, tin distearate, and tin dinaphthenate; dibutyltin dicarboxylates such as dibutyltin dilaurate and dibutyltin bis(alkylmaleate); alkoxide derivatives of dialkyltin such as dibutyltin dimethoxide and dibutyltin diphenoxide; intramolecular coordination derivatives of dialkyltin such as dibutyltin diacetylacetonate, dibutyltin acetoacetate, dibutyltin diethylhexanoate, dibutyltin dioctate, dibutyltin oxide, dibutyltin bisethoxysilicate, and dioctyltin oxide; and derivatives of tetravalent dialkyltin oxide such as reaction mixtures of dibutyltin oxide and ester compounds, reaction mixtures of dibutyltin oxide and silicate compounds, and oxy derivatives of these dialkyltin oxide derivatives. Examples of non-tin metal catalysts include calcium carboxylates having octylic acid, oleic acid, naphthenic acid, stearic acid, etc. as the carboxylic acid component; and metal salts of carboxylates such as zirconium carboxylate, iron carboxylate, vanadium carboxylate, bismuth carboxylate, lead carboxylate, titanium carboxylate, and nickel carboxylate. Among these, tetravalent tin catalysts are preferred. The curing catalysts may be used alone or in combination of two or more.

In addition, when the (A) reactive polymer is an isocyanate group-containing polymer, examples of the reactive polymer include tin octylate, tin naphthenate, tin stearate, dibutyltin dioctoate, dibutyltin dilaurate, dioctyltin diversatate, dibutyltin bistriethoxysilicate, dibutyltin dioleyl maleate, dibutyltin diacetate, 1,1,3,3-tetrabutyl-1,3-dilauryloxycarbonyl-distannoxane, dibutyltin oxybisethoxysilicate, dibutyltin oxide, a reaction product of dibutyltin oxide and a phthalic acid ester, a reaction product of dibutyltin oxide and a maleic acid diester, dibutyltin diacetylacetonate, etc. Other organometallic compounds include carboxylic acid (e.g., octylic acid) salts of bismuth, barium, calcium, indium, titanium, zirconium, calcium, zinc, iron, cobalt, and lead, such as bismuth octylate and calcium octylate. Among these, tetravalent tin catalysts are preferred. One type of curing catalyst may be used alone, or two or more types may be used in combination.

In order to improve the stability of the (C) curing catalyst against water, a carboxylic acid can be used in addition to these catalysts as a catalyst stabilizer. This is particularly suitable when an isocyanate group-containing polymer is used as the (A) reactive polymer. Examples of such carboxylic acids include aromatic carboxylic acids such as benzoic acid and phthalic acid; aliphatic carboxylic acids such as octylic acid (2-ethylhexanoic acid), stearic acid, oleic acid, and linoleic acid; and resin acids such as abietic acid, neoabietic acid, dehydroabietic acid, pimaric acid, isopimaric acid, and parastric acid. Each of these may be used alone or in combination of two or more. Of these, octylic acid is preferred.

The plasticizer (D) contained in composition (I) may be a hydrocarbon such as paraffin, naphthene, or polybutene, as long as it does not interfere with the flash point, viscosity, or paint adhesion. Phthalic acid diesters (diisononyl phthalate (DINP), etc.), epoxidized hexahydrophthalic acid diesters, alkylene dicarboxylate diesters, alkylbenzenes, etc. may also be used as long as it does not interfere with the paint adhesion or viscosity. Polymeric plasticizers may also be used in the same range as other plasticizers.

Examples of polymeric plasticizers include vinyl polymers obtained by polymerizing vinyl monomers by various methods; esters of polyalkylene glycols such as diethylene glycol dibenzoate, triethylene glycol dibenzoate, and pentaerythritol ester; polyester plasticizers obtained from dibasic acids such as sebacic acid, adipic acid, azelaic acid, and phthalic acid and dihydric alcohols such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, and dipropylene glycol; polyether polyols such as polyethylene glycol, polypropylene glycol, and polytetramethylene glycol having a molecular weight of 500 or more, preferably 1000 or more, or derivatives in which the hydroxyl groups of these polyether polyols are converted to ester groups, ether groups, etc.; polystyrenes such as polystyrene and poly-α-methylstyrene; polybutadiene, polybutene, polyisobutylene, butadiene-acrylonitrile, and polychloroprene, but are not limited to these. The polymer plasticizer may or may not have a reactive silicon group, but if it has a reactive silicon group, migration of the plasticizer from the cured product can be prevented. If it has a reactive silicon group, it is preferable that there is an average of one or less reactive silicon groups per molecule, and more preferably 0.8 or less reactive silicon groups.

Other additives may be added to composition (I) as necessary. Examples of such additives include colorants, thixotropic agents, adhesion agents, stabilizers, antioxidants, solvents, UV absorbers, light stabilizers, etc.

There are no particular limitations on the coloring agent, and it can be selected appropriately depending on the color of the wall material. Examples include red iron oxide, titanium oxide, carbon black, other color pigments, dyes, etc.

Examples of thixotropic agents include colloidal silica, organic bentonite, amide wax, and hydrogenated castor oil.

Examples of adhesives include silane coupling agents such as aminosilane, mercaptosilane, epoxysilane, and silicate esters, epoxy compounds, and acrylic oligomers.

Examples of antioxidants include phenol-based antioxidants such as hindered phenols.

Examples of solvents include methanol, ethanol, isopropanol, n-butanol, acetone, methyl ethyl ketone, ligroin, ethyl acetate, tetrahydrofuran, n-hexane, heptane, and isoparaffin-based solvents.

Examples of UV absorbers and light stabilizers include benzotriazoles and hindered amines.

The composition of each of the above components contained in composition (I) can be appropriately determined depending on the type of (A) reactive polymer, etc. Examples of the case where (a) a hydrolyzable silyl group-containing polyether polymer is used as the (A) reactive polymer and the case where (b) a terminal NCO-containing prepolymer is used are as follows.

In the case of (a), it is preferable that (A) the reactive polymer is 10 to 50 mass% in composition (I), (B) the filler is 1 to 75 mass% in composition (I), (C) the curing catalyst is 1 to 12 mass% relative to (A) the reactive polymer, and (D) the plasticizer is 1 to 50 mass% in composition (I). In addition, it is preferable that the total amount of other additives is 0.01 to 50 mass% in composition (I).

In the case of (b), the component composition of composition (I) can be determined based on the components before synthesis of the base component (A) reactive polymer. The polyol constituting the base component is preferably 10 to 50 mass% in composition (I), the polyisocyanate constituting the base component is preferably 1 to 10 mass% in composition (I), the filler (B) is preferably 0 to 70 mass% in composition (I), the curing catalyst (C) is preferably 0.0001 to 5 mass% relative to composition (I), and the plasticizer (D) is preferably 0 to 50 mass% in composition (I). The other additives are preferably 0.01 to 50 mass% in total in composition (I).

Composition (I) may be configured so that, when cured, the time required for the surface layer from the outer surface to 0.5 mm in the thickness direction to cure is preferably 8 hours or less, more preferably 6 hours or less, and even more preferably 5 hours or less under conditions of 23°C and a relative humidity of 50% RH. This makes it possible to start applying composition (II) before complete curing, thereby shortening the construction period. The curing time of the surface layer of composition (I) can be controlled, for example, by adjusting the catalyst type, catalyst amount, the type of reactive group of the reactive polymer, the skeletal structure of the reactive polymer, and the pH.

The composition (I) preferably has a viscosity of 200,000 to 5,000,000 mPa·s at a shear rate of 2.1 sec ^-1 , more preferably 200,000 to 1,000,000 mPa·s. This provides a material with a good balance between workability (ejectability and dripping) as a sealant. Such a viscosity can be measured by the method described below. The viscosity of such composition (I) is controlled, for example, by the polymer viscosity, and can be increased by adjusting it with a filler or the like, or decreased by using a plasticizer or solvent.

The tensile elongation at break of the cured product of composition (I) is not particularly limited, and may be any value generally used for sealing materials. For example, a tensile elongation at break of 500% or more, preferably 600% or more, is desirable.

The (A') reactive polymer, (B') filler, (C') curing catalyst, (D') plasticizer, and other additives that may be contained in composition (II) may be the same as those in composition (I). These may be appropriately selected depending on the component composition of composition (I).

However, the (A') reactive polymer has the same functional group as the functional group contained in the (A) reactive polymer. The functional group contained in this (A) reactive polymer means a reactive functional group. Therefore, the (A') reactive polymer has the same reactive functional group as the reactive functional group contained in the (A) reactive polymer. This ensures the adhesion between the compositions (I) and (II).

It is preferable that the (A') reactive polymer has a main skeleton similar to that of the (A) reactive polymer. This ensures adhesion between compositions (I) and (II) and also makes the physical properties relatively similar, allowing them to follow the expansion and contraction of the wall material.

Among the other additives, the colorant is selected to have a different color (shade) from that of composition (I) in order to form a mottled pattern. Such color combinations are selected according to the design of the surface of the wall material. The standard for such color combinations can be determined based on ΔL, which is the difference in L* between composition (I) and composition (II) after curing, described below (L*(composition (II))-L*(composition (I))). ΔL is preferably 0.5 to 50, more preferably 5 to 30, and even more preferably 5 to 20. When ΔL is within this range, the patterns of the wall material and the sealant tend to harmonize and produce a natural finish.

The viscosity of the composition (II) at a shear rate of 2.1 sec ^-1 is preferably 50,000 to 5,000,000 mPa·s, more preferably 200,000 to 1,000,000 mPa·s. This suppresses dripping and makes it easier to form a non-uniform coating film with a mottled pattern. Such a viscosity can be measured by the method described below. The viscosity of the composition (II) can be controlled, for example, by the same method as that of the composition (I).

Composition (II) is preferably configured so that the tensile breaking elongation of the cured product is 100% or more, and more preferably 200% or more. This makes it possible to more effectively suppress cracking, peeling, etc. of the cured product of composition (II) even if the coating film is formed unevenly to have a mottled pattern. In addition, the cured product of composition (II) only needs to be able to follow the reversible deformation of the cured product of composition (I), and there is no particular upper limit to the tensile breaking elongation. The tensile breaking elongation of composition (II) can be controlled by, for example, the type of reactive polymer, the amount of plasticizer, or the amount of filler.

There is no particular limit to the thickness of the coating film of composition (II) as long as it harmonizes with the pattern of the wall material, but as described below, when removing the masking tape applied to the joints before applying composition (II) to the cured surface of composition (I), the cured product may be deformed at the broken part by being caught in the masking tape. From the viewpoint of preventing this, it is preferable to adjust the thickness to a predetermined range according to the component composition of composition (II). For example, when a hydrolyzable silyl group-containing polyether polymer (modified silicone) is used as the reactive polymer, it is preferable to make the thickness less than 5 mm, and more preferably 3 mm or less. From the viewpoint of hiding power, 0.1 mm or more is preferable.

The architectural sealant according to the embodiment of the present invention is formed by applying composition (II) to the surface of the cured product of composition (I) described above in a partially mottled pattern. When the surface of the cured product of composition (I) is partially covered with the cured product of composition (II), the area ratio covered by the cured product of composition (II) (composition (II)/composition (I)) can be determined according to the surface design of the wall material to be used, but from the viewpoint of harmony with various wall material designs, 10 to 70% is preferable.

The wall material to which the architectural sealant according to the embodiment of the present invention can be applied is not particularly limited, but it is preferable that the wall material has a design that harmonizes with the mottled pattern formed on the sealant. Such wall materials include those that constitute the exterior walls and interior walls of buildings. Examples of exterior walls of buildings include the exterior walls of various buildings, detached houses, apartment buildings, etc. Materials that constitute exterior walls include inorganic boards such as precast concrete boards and fiber-reinforced concrete boards, metal boards such as aluminum curtain walls, ceramic siding boards such as cement boards, fiber-reinforced cement boards, and extruded cement boards, and metal siding boards. In addition, it is preferable that the surfaces of these materials are colored in a wide variety of colors or patterned to give the appearance of tiles or natural stone.

In this way, it is preferable that the surface of the wall material has the same mottled pattern as the sealant formed by combining the above-mentioned compositions (I) and (II). In other words, it is preferable that the mottled pattern on the sealant surface is the same as the mottled pattern on the adjacent wall material surface. Here, "the same pattern" includes not only a completely identical pattern, but also a mottled pattern in which the patterns on the surfaces of the adjacent wall material and sealant are in harmony.

As described below, when such wall materials are used for the exterior walls of buildings, multiple wall materials are generally installed with a certain gap (joint) formed, and the above-mentioned composition (I) is poured into the gap. There is no particular limit to the width of this gap, but from the viewpoint of more effectively exerting the sealing function of the cured product of composition (I), a width of 5 to 30 mm is preferable. This gap width is more suitable when the wall material is a ceramic siding board.

(Set for forming architectural sealant with a mottled pattern)
The set for forming an architectural sealant having a mottled pattern according to the embodiment (hereinafter, sometimes simply referred to as an "architectural sealant set") includes the above-mentioned composition (I) and composition (II) contained in separate containers (I) and (II), respectively, and combined. By providing them in such a combination, the application of the architectural sealant having the above-mentioned mottled pattern can be easily performed. This architectural sealant set may include an application tool for applying the composition (II) as necessary.

Since both compositions (I) and (II) contain a reactive polymer, it is necessary to react the reactive polymer when applying the architectural sealant. Therefore, compositions (I) and (II) are prepared and used immediately before application. In other words, the compositions (I) and (II) contained in containers (I) and (II) are different in appearance before and after preparation, but "contained in container (I)" and "contained in container (II)" include both aspects. Specifically, after preparation, compositions (I) and (II) contained in containers (I) and (II) are a mixture of the respective components that constitute them. On the other hand, before preparation, at least the reactive polymer and the curing catalyst are further contained in separate containers depending on the type of reactive polymer. When the reactive polymer is, for example, modified silicone, for example, the curing catalyst and other components are contained in separate containers, and these are contained together in a container. In addition, when the reactive polymer is a terminal NCO-containing prepolymer, the terminal NCO-containing prepolymer, the solvent added as necessary, and other components are contained in separate containers, and these are then contained together in the container.

(Method of applying architectural sealant having a mottled pattern)
The method for applying the architectural sealant having a mottled pattern according to the embodiment is a method for forming an architectural sealant having a mottled pattern in the gaps, i.e., joints, formed between a plurality of wall materials using the wall materials such as the siding boards and the compositions (I) and (II). Specifically, the application can be performed, for example, as follows.

First, a process is carried out in which multiple wall materials are installed in predetermined positions with gaps (joints) formed at predetermined intervals. The width of the gap is not particularly limited, but a width of 5 to 30 mm is preferable. There is no particular limit to the wall material used, but siding boards are preferable, and ceramic siding boards are more preferable. There is no particular limit to the design of the wall material surface, but it is preferable for a mottled pattern to be formed.

Next, the aforementioned composition (I) is poured into the formed joint, and the surface of the poured composition (I) is smoothed to form a primer layer. It is preferable that the surface height of the primer layer is the same as or slightly lower than the surface of the wall material, and a recess is formed.

Next, after the surface of the undercoat layer is cured, the above-mentioned composition (II) is applied to partially cover the surface of the undercoat layer to form a mottled pattern. The surface of the undercoat layer is preferably cured to a thickness of 0.5 mm or more from the surface. The curing time is preferably 8 hours or less, more preferably 3 hours or less, and even more preferably 2 hours or less under conditions of 23°C and 50% RH. The thickness of the coating film of composition (II) is not particularly limited as long as it is in harmony with the design of the surface of the wall material, but when masking tape is used as described below, it can be appropriately determined according to the component composition from the viewpoint of suppressing deformation of the cured product of composition (II). The method of applying composition (II) is not particularly limited and can be appropriately selected according to the characteristics of composition (II), and examples include spray application, spread coating, etc. Spray application can be performed using a known spray gun, sprayer, etc. The painting tools used in the spread coating are preferably ones that are easy to form a mottled pattern, such as those with wrinkles on the surface or those with soft hair or fibers, such as sponges, brushes, benders, work gloves, and wrap rolled up to be wrinkled. Of these, wrap rolled up to be wrinkled is particularly suitable from the viewpoint of efficiently forming a mottled pattern that harmonizes with the various mottled patterns and other designs of the wall material. In addition, composition (II) is preferably applied so that it partially covers 10 to 70% of the surface area of composition (I) depending on the pattern of the wall material.

Then, composition (II) is cured to form a construction sealant having a mottled pattern.

In addition, it is preferable to apply masking tape to the joints of the wall material from the viewpoint of preventing contamination of the wall material. The masking tape may be applied before pouring the composition (I), or after pouring the composition (I) and before applying the composition (II). In addition, in order to adjust the thickness of the coating film of the composition (II), a spacer may be provided on the surface of the masking tape as necessary. It is preferable that the spacer is removable after applying the composition (II) and before curing. After the composition (II) has cured, the masking tape is removed. As described above, by adjusting the thickness according to the component composition of the composition (II), deformation of the cured product of the composition (II) is suppressed when removing the masking tape.

As described above, by using the above-mentioned compositions (I) and (II), when a highly decorative wall material is used, a sealant with a mottled pattern that harmonizes with the design of the wall material can be easily applied.

The architectural sealant using the aforementioned compositions (I) and (II) can be used when forming the exterior walls of buildings using highly decorative wall materials, allowing the entire exterior wall to have a unified design. Even if a certain period of time has passed since the construction of such an exterior wall and the pattern of the wall material has changed, it is possible to form an exterior wall with a unified design again by applying a sealant that matches the changed pattern of the wall material. In this case, the original sealant used when the exterior wall was installed can be removed according to standard procedures, and the architectural sealant described above can be applied anew.

The following describes the embodiment of the present invention in detail based on examples.

The components used in the examples and comparative examples are as follows. The reactive polymer used was (1) modified silicone or (2) polyurethane prepolymer having isocyanate groups, which was obtained by synthesis.

(1) Modified silicone (reactive polymer)
Polyether-based polymer having a dimethoxymethylsilyl group at the end as a reactive silyl group, manufactured by Kaneka Corporation, Kaneka MS Polymer (registered trademark) S203 ("S203" in Table 1)
Acrylic polymer having a hydrolyzable silyl group as a reactive silyl group, telechelic polyacrylate XMAP SB802S manufactured by Kaneka Corporation (referred to as "SB802S" in Table 1)
(filler)
Surface-treated calcium carbonate: fatty acid surface treatment, manufactured by Shiraishi Calcium Co., Ltd., CCR-B ("CCR-B" in Table 1)
Heavy calcium carbonate: Shiraishi Calcium Co., Ltd., 300M ("300M" in Table 1), Whiten SB ("Whiten SB" in Table 1)
(Curing catalyst)
Dibutyltin triethylsilicate: Neostan U-303 manufactured by Nitto Kasei Co., Ltd. (referred to as "Neostan U-303" in Table 1)
4:6 mixture of di-n-butyltin oxide and diisononyl phthalate: DSC4 manufactured by Daikyo Chemical Industry Co., Ltd. ("DSC4" in Table 1)
(Plasticizer)
Phthalate esters: diisononyl phthalate ("DINP" in Table 1)
Polyether polyol: AGC Corporation, Exenol 3020 ("Exenol 3020" in Table 1), number average molecular weight Mn = 3200, average number of functional groups f = 2, OH value = 35
(Thixotropic Agent)
Amide wax: A-S-A T-1800, manufactured by Ito Oil Mills Co., Ltd. ("A-S-A T-1800" in Table 1)
(Adhesive)
Aminosilane coupling agent: KBM-603 manufactured by Shin-Etsu Chemical Co., Ltd. (referred to as "KBM-603" in Table 1)
Tetraethyl silicate: Dynasylan A manufactured by Evonik Japan Co., Ltd. (referred to as "Dynasylan A" in Table 1)
(Antioxidant)
Phenol-based antioxidant: Adeka STAB AO-60P, manufactured by Adeka Corporation (referred to as "AO-60P" in Table 1)
(Coloring Agent)
Gray toner (A) ("Gray toner (A)" in Table 1): A mixture of the black toner and white toner shown below in a mass ratio (black/white) of 1/205. Gray toner (B) ("Gray toner (B)" in Table 1): A mixture of the black toner and white toner shown below in a mass ratio (black/white) of 1/58. Gray toner (C) ("Gray toner (C)" in Table 1): A mixture of the black toner and white toner shown below in a mass ratio (black/white) of 1/410. Black toner: A mixture of carbon black (X) and DINP (Y) in a mass ratio (X/Y) of 40/60. White toner: A mixture of titanium oxide (Z) and DINP (Y) in a mass ratio (Z/Y) of 50/50.

(2) Polyurethane prepolymer having isocyanate groups <substrate>
(i) Polyol: AGC Corporation, Exenol 2020 ("Exenol 2020" in Table 2), number average molecular weight Mn = 2000, average number of functional groups f = 2, OH value = 56
(ii) Diisocyanate Toluene diisocyanate (TDI) ("TDI" in Table 2), 100% by weight of 2,4-isomer
(iii) Solvent Isoparaffinic hydrocarbon: Idemitsu Supersol FP-38 manufactured by Idemitsu Kosan Co., Ltd. (referred to as "FP-38" in Table 2)
<Curing Agent>
(i) Polyol: Sannix CH-5000 (referred to as "Sanix CH-5000" in Table 2), manufactured by Sanyo Chemical Industries, Ltd.; number average molecular weight Mn = 5000; average number of functional groups f = 3; OH value = 33
(ii) Catalyst Bismuth octylate catalyst: Neostan U-660 manufactured by Nitto Chemical Industry Co., Ltd. (referred to as "Neostan U-660" in Table 2)
Octylic acid metal soap: Nikka Octix Ca 5% manufactured by Nippon Chemical Industries Co., Ltd. ("Nikka Octix Ca 5%" in Table 2)
(iii) Catalyst stabilizer: Octylic acid ("Octylic acid" in Table 2), manufactured by Chisso Corporation
(iv) Adhesion agent Acrylic compound: ARONIX ST-300 manufactured by Toagosei Co., Ltd. (referred to as "ARONIX ST-300" in Table 2)
(v) Filler Surface-treated calcium carbonate: fatty acid surface-treated colloidal calcium carbonate, manufactured by Takehara Chemical Industry Co., Ltd., Neolite SP-T ("Neolite SP-T" in Table 2)
Heavy calcium carbonate: Shiraishi Calcium Co., Ltd., 300M ("300M" in Table 2)
(vi) Plasticizers Phthalate esters: diisononyl phthalate ("DINP" in Table 2)
(vii) Colorant: Gray toner (A) ("Gray toner (A)" in Table 2), gray toner (B) ("Gray toner (B)" in Table 2) used in the modified silicone.

(3) Partial Coating Composition Used in Comparative Example 1 (Composition (II))
Urethane-based paint: SK Chemical Co., Ltd., product name Clean Mild Urethane ("Composition (II) E" in Table 3)

(Production Examples 1 to 8)
The materials other than the catalyst were mixed in a planetary mixer for 60 minutes to obtain the composition shown in Table 1, and then mixed at 80°C under vacuum and reduced pressure for 2 hours. Next, after cooling to 30°C, the catalyst was added to obtain the composition shown in Table 1, and the mixture was stirred at 30°C or less under vacuum and reduced pressure for 15 minutes to obtain (I) architectural sealant compositions ("composition (I)" in Table 1) A to E (production examples 1 to 5, respectively) and (II) partial coating compositions ("composition (II)" in Table 1) A to H (production examples 6 to 8, respectively). The units of the compositions in Table 1 are mass %.

(Production Examples 9 and 10)
Polyol and TDI were reacted at 85°C for 10 hours to obtain a polyurethane prepolymer with an isocyanate group (NCO) content of 3.0% by weight, so as to obtain the composition shown in Table 2 under "base material". Isoparaffinic hydrocarbon was mixed and stirred with the polyurethane prepolymer to obtain a base material, so as to obtain the composition shown in Table 2 under "curing agent". After mixing and stirring each material to obtain a curing agent, so as to obtain the composition shown in Table 2 under "curing agent", the base material and the curing agent were mixed at a ratio of 1:4 (by weight) to obtain (I) architectural sealant composition ("composition (I)" in Table 2) F (Production Example 9) and (II) partial coating composition ("composition (II)" in Table 2) D (Production Example 10). The units of the compositions in Table 2 are mass%.

(Rating 1)

<Coatability of Composition (I)>
After preparing a joint with a width of 10 mm, a depth of 10 mm, and a length of 100 mm, compositions (I) A to F were poured and left to stand at a temperature of 23°C and a humidity of 50% RH. After pouring, the joint was cut every hour, and the uncured portion was removed. The depth in the thickness direction from the outer surface of the cured portion was measured using a ruler. The time after pouring when the thickness from the outer surface of the cured portion became 0.5 mm or more was recorded. The results are shown in Table 3.

<Tensile elongation at break of cured products of compositions (I) and (II)>
Using compositions (I) A to F obtained in Production Examples 1 to 5 and 9, and compositions (II) A to D obtained in Production Examples 6, 7, 8 and 10, dumbbell-shaped No. 3 specimens were prepared as JIS K 6251 (2017) test pieces, and tensile tests were performed. The test pieces had a thickness of 2 mm, and were aged at 23°C and a humidity of 65% RH for 2 weeks. The results are shown in Table 3.

<Viscosity of Compositions (I) and (II)>
The viscosity after 1 minute was measured at a shear rate of 2.1 sec-1 using a BS type viscometer No. 7 rotor in an environment of 20°C using compositions (I) A to F obtained in Production Examples 1 to 5 and 9 and compositions (II) A to D obtained in Production Examples 6, 7, 8 and ^10. The results are shown in Table 3.

(Rating 2)
Using the combination sets of Compositions (I) A to F and Compositions (II) A to D shown in Tables 3 to 5, construction sealants were prepared and evaluated as follows. The evaluation results are shown in Tables 3 to 5.

<Appearance and ΔL>
Compositions (I) A to F obtained in Production Examples 1 to 5 and 9 were poured into joints with a width of 10 mm and a depth of 10 mm, and cured until the surface layer of each composition (I) from the outer surface to 0.5 mm in the thickness direction was cured. After that, a wrap (manufactured by Asahi Kasei Home Products, product name Saran Wrap (registered trademark)) was rolled up so as to wrinkle, and an appropriate amount of compositions (II) A to D was attached and partially applied (spread coating) to the outer surface of compositions (I) A to F. Curing was performed for 7 days at 23°C and 50% RH, and the appearance was observed and ΔL was calculated. The appearance was confirmed visually. ΔL was calculated by measuring L* for the cured products of compositions (I) and (II) as follows, and the difference between the two (L*(composition (II))-L*(composition (I))). L* was measured using a spectrophotometer (manufactured by Nippon Denshoku Kogyo Co., Ltd., handy colorimeter NR-12A). Incidentally, L* is a value obtained by irradiating the coating surface with light at an angle of 45° to the axis perpendicular to the coating surface, and measuring the color of the reflected light perpendicular to the coating surface. The evaluation criteria are as follows. The evaluation results are shown in Table 3.
Appearance: Spotted: ○, Not spotted: ×
When ΔL is 0.5-50, the pattern of the sealant and the exterior wall are in harmony, resulting in a natural finish.

<Dynamic durability>
Using two L-shaped cross-section angles, a joint of 20 mm wide x 20 mm deep x 100 mm long was prepared, and the composition (I) was poured into the joint, followed by curing at 23°C and 50% RH until complete curing. Next, the composition (II) was applied (spread coating) to the outer surface of the cured composition (I) in a mottled pattern using a wrap rolled up to be wrinkled in the same manner as described above, and then cured at 23°C and 50% RH for 7 days. The thickness of the composition (II) in the resulting architectural sealant was 0.1 to 0.5 mm. The resulting architectural sealant was used to repeat compression and expansion up to 10,000 times at 23°C so that the displacement of the distance between the opposing angles was 20%, and then the surface was visually observed. The evaluation criteria are as follows. The evaluation results are shown in Table 3.
Appearance: no cracks in the cured product of composition (II): ◯, cracks in the cured product of composition (II): ×

<Masking removal ability>
A joint was prepared using mortar to have a width of 10 mm and a depth of 10 mm. Composition (I) B was poured into the resulting joint, and the surface was smoothed to form a primer layer. The joint was then cured at 23°C and 50% RH until it was completely cured. Masking tape was applied to the joint, and spacers were placed on top of the masking tape to give each film thickness (Examples 7 to 10) shown in Table 4, and composition (II) A was applied (spread coating). The spacers were removed before curing. The joint was then left to stand for 12 hours at 23°C and 50% RH. The masking tape was then peeled off, and the appearance was observed. The evaluation criteria were as follows: when the masking tape was peeled off, the cured product of composition (II) A was caught in the joint and changed in shape, it was marked "x", when the product was not caught in the joint and did not change in shape, it was marked "○", and when the product changed in shape slightly but did not change significantly, it was marked "△". The evaluation results are shown in Table 4.

<Coverage rate and appearance>
<<Preparation of sealing material>>
Compositions (I) A and D obtained in Production Example 1 were each poured into a joint having a width of 10 mm and a depth of 10 mm, and cured until the surface layer of each composition (I) from the outer surface to 0.5 mm in the thickness direction hardened. After that, a wrap (manufactured by Asahi Kasei Home Products, product name Saran Wrap (registered trademark)) was rolled up so as to wrinkle, and appropriate amounts of compositions (II) A and B were attached and partially applied (spread coating) to the outer surfaces of compositions (I) A and D, respectively. At this time, the amount of each composition (II) attached was changed, and the coverage area ratio of composition (II) was changed as shown in Table 5 (Examples 11 to 16). The specimens were cured for 7 days at 23°C and 50% RH, and the appearance was observed and the coverage area ratio of composition (II) was calculated. The appearance was confirmed by visual inspection. The evaluation criteria for appearance were "○" as a mottled pattern, "△" as a state in which the composition (II) was slightly more or slightly less, and "×" as a state in which the composition (II) was more or less and no mottled pattern was observed. The evaluation results are shown in Table 5. The coverage rate was calculated as follows.

<<Calculation of coverage area rate>>
The surface of the sealant after curing was photographed at 20x magnification using an optical microscope (VHX-600, manufactured by KEYENCE Corporation). Based on the photographs, the area (total area) of the cured product of composition (I) and the area of the cured product of composition (II) were measured, and the ratio of the area of the cured product of composition (II) to the total area was calculated as the coverage area rate. The measurements were performed using image processing software attached to the optical microscope. The measurement and calculation results are shown in Table 5. Each photograph is shown in Figures 1 to 6.

From Tables 3 to 5 and Figures 1 to 6, it can be seen that by using a combination of the specified compositions (I) and (II), it is possible to provide a construction sealant that can produce a mottled pattern similar to that of a siding board, can suppress the occurrence of cracks in the cured product of composition (II), and can shorten the construction period compared to conventional methods.

Claims (14)

A sealant for construction comprising (I) a cured product of a sealant composition for construction and (II) a cured product of a partial coating composition partially formed on the surface of the cured product,
The architectural sealant has a mottled pattern formed by partially covering a surface of a cured product of the architectural sealant composition (I) containing a reactive polymer (A), a filler (B) and a curing catalyst ( C ) with a cured product of the partial-coating coating composition (II) containing a reactive polymer (A') having the same functional group as that contained in the reactive polymer (A);
the tensile elongation at break of the cured product of the partial coating composition (II) is 100% or more;
A construction sealant, in which the difference ΔL between the L* of the cured product of the partial coating composition (II) and the L* of the cured product of the construction sealant composition (I) is 0.5 to 50 as measured by a spectrophotometer . The architectural sealant according to claim 1, wherein the functional group contained in the reactive polymer (A) is a silyl group or an isocyanate group, and the main skeleton of the reactive polymer (A) contains a polyoxyalkylene skeleton and/or a (meth)acrylic acid ester skeleton. The architectural sealant according to claim 1 or 2, wherein the surface area ratio of the cured product of the partial coating paint composition (II), which partially coats the surface of the cured product of the architectural sealant composition (I), is 10 to 70%. The architectural sealant according to any one of claims 1 to 3, wherein the cured product of the architectural sealant composition (I) is placed in a gap of 5 to 30 mm between two or more ceramic siding boards. The architectural sealant according to claim 4, wherein the surface of the ceramic siding board is formed with the same pattern as the mottled pattern. The architectural sealant according to any one of claims 1 to 5, wherein the (II) partial coating composition contains the (A') reactive polymer, the (C') curing catalyst, and the (D') plasticizer. A method for applying an architectural sealant having a mottled pattern, comprising casting an architectural sealant between wall materials, the architectural sealant being composed of (I) a cured product of an architectural sealant composition and (II) a cured product of a partial coating composition partially formed on a surface of the cured product, the method comprising the steps of:
A step of installing a plurality of wall materials at predetermined positions while forming gaps at predetermined intervals;
A step of pouring the architectural sealant composition (I) into the gap, smoothing the surface, and forming an undercoat layer;
After curing the surface of the undercoat layer, the partial coating coating composition (II) is applied in a mottled pattern;
Including,
The architectural sealant composition (I) contains (A) a reactive polymer, (B) a filler, and (C) a curing catalyst,
The method for applying an architectural sealant, wherein the (II) partial coating coating composition contains an (A') reactive polymer having the same functional group as the functional group contained in the (A) reactive polymer, and the tensile break elongation of the cured product of the (II) partial coating coating composition is 100% or more . The method for applying the architectural sealant according to claim 7, wherein the partial coating composition (II) is applied by spray application or spread coating. The method for applying the architectural sealant according to claim 7 or 8, wherein the surface curing time of the undercoat layer is 5 hours or less to cure to a thickness of 0.5 mm from the surface under conditions of 23°C and 50% RH. A set for forming an architectural sealant having a mottled pattern, comprising (I) an architectural sealant composition contained in a container (I) and (II) a partial coating composition contained in a container (II),
The architectural sealant composition (I) contains (A) a reactive polymer, (B) a filler, and (C) a curing catalyst,
The (II) partial coating coating composition contains an (A') reactive polymer having the same functional group as the functional group contained in the (A) reactive polymer, and the (II) partial coating coating composition has a cured product with a tensile breaking elongation of 100% or more. The set for forming an architectural sealant having a mottled pattern according to claim 10, wherein the time required for the surface layer of the architectural sealant composition (I) from the outer surface to 0.5 mm in the thickness direction to harden is 5 hours or less under conditions of 23°C and a relative humidity of 50% RH when the architectural sealant composition (I) is hardened. The set for forming an architectural sealant having a mottled pattern according to claim 10 or 11, wherein the viscosity of the architectural sealant composition (I) and the partial coating composition (II) at a shear rate of 2.1 sec ^-1 is 200,000 to 5,000,000 mPa·s. the functional group contained in the reactive polymer (A) is at least one hydrolyzable silyl group selected from a trimethoxysilyl group and a dimethoxymethylsilyl group,
The set for forming an architectural sealant having a mottled pattern according to any one of claims 10 to 12, wherein the (C) curing catalyst is a tetravalent tin-based catalyst, and the content thereof is 0.1 to 12% by mass relative to the (A) reactive polymer containing a hydrolyzable silyl group. The (I) architectural sealant composition contains (D) a plasticizer,
The set for forming an architectural sealant having a mottled pattern according to any one of claims 10 to 13, wherein the partial coating composition (II) contains a filler (B') and a plasticizer (D').