Exterior wall tile waterproofing structure and exterior wall tile waterproofing method

Abstract

To provide a waterproof structure of an outer wall tile and a waterproof construction method of an outer wall tile that provide waterproofness without spoiling designability of a tile attached to a building structure.SOLUTION: A waterproof structure of an outer wall tile is characterized by forming a transparent primer layer, a transparent intermediate coating layer, and a transparent protective layer. The transparent primer layer is formed by coating a face and a joint of an outer wall tile with a silicon acrylic resin primer containing an amino-group-containing acryl resin and epoxysilane. The transparent intermediate coating layer is formed by applying a transparent polyurea resin coating material containing an adduct of a non-yellowing isocyanate prepolymer with a number average of functional groups of 3.5-4.5, an alicyclic polyamine having only a secondary amino group, hydrophilic fine powder silica, a rheology control agent, a light stabilizer, an ultraviolet absorber, and a silane compound having two or more alkoxy groups bonded to a silicon atom in one molecule. The transparent protective layer is formed by applying an acrylic silicon resin coating material containing a light stabilizer and an ultraviolet absorber.SELECTED DRAWING: None

Description

[Technical Field]

[0001] This invention relates to an exterior wall tile waterproofing structure and an exterior wall tile waterproofing method that can prevent deterioration of the structural concrete and tile-attached mortar due to rainwater penetration without impairing the aesthetic design of the exterior wall tiles installed on existing buildings. [Background technology]

[0002] Traditionally, concrete buildings have had tiles applied to their exterior surface for purposes such as preventing concrete carbonation and adding aesthetic appeal. However, rainwater can penetrate the tile surface, joints, or cracks in these areas, reaching the concrete and the mortar used to attach the tiles, leading to deterioration. Therefore, the formation of a waterproof structure for exterior wall tiles has become necessary.

[0003] For example, Patent Document 1 discloses a method for repairing an existing exterior tile wall surface that can enhance its waterproofing properties. This method involves applying a transparent primer to the existing exterior tile wall surface to form a primer layer, applying a main material paint mainly composed of a transparent acrylic resin emulsion multiple times to the primer layer to form a main material layer, and applying a transparent topcoat paint to the main material layer to form a topcoat layer. The main material paint is characterized in that it contains reinforcing short fibers, has a viscosity of 20,000 to 70,000 mPa·s, and a thixotropy index of 4.0 to 10.0.

[0004] Furthermore, in Patent Document 2, the applicant discloses an exterior wall tile peeling prevention structure characterized by the following: a structure to be formed on exterior wall tiles, in which anchor pins are driven into the exterior wall tile surface or joints to fix the anchor pins to the concrete structure; a transparent primer layer is formed by applying a silicone acrylic resin primer containing an amino group-containing acrylic resin and epoxy silane to the heads of the anchor pins, the exterior wall tile surface, and the joints; a transparent reinforcing layer is formed by applying a transparent polyurea resin coating material containing a non-yellowing isocyanate prepolymer with an NCO weight of 5-10% by weight, an alicyclic polyamine, transparent reinforcing short fibers, hydrophilic fine silica powder, a rheology control agent, a light stabilizer, and an ultraviolet absorber on the transparent primer layer; and a transparent protective layer is formed by applying an acrylic silicone resin coating material containing a light stabilizer and an ultraviolet absorber on the transparent reinforcing layer. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2007-247279 [Patent Document 2] Japanese Patent Publication No. 2016-030974 [Overview of the project] [Problems that the invention aims to solve]

[0006] However, the repair method for existing exterior tile walls described in Patent Document 1 has the problem of having many construction steps because it involves applying a main coating consisting mainly of a transparent acrylic resin emulsion multiple times to form the main material layer. Furthermore, because it uses a one-component acrylic resin emulsion that requires film formation at the application temperature, the glass transition temperature (Tg) of the acrylic resin is low. If the repair surface reaches 50°C or higher in areas exposed to direct sunlight, such as the south-facing side of a building, the tensile strength at that temperature will be low, and cracks may form in the coating in areas where cracks have occurred in the substrate, resulting in a loss of waterproofing. In addition, even if the temperature of the repair surface does not rise, the main material layer is a layer formed by the drying of multiple applications of acrylic resin emulsion, making it difficult to achieve high initial tensile strength. As a result, the coating may deteriorate and lose its waterproofing due to the effects of ultraviolet rays over a long period of time.

[0007] Furthermore, while the exterior wall tile delamination prevention structure described in Patent Document 2 has the excellent effect of preventing the delamination of exterior wall tiles, depending on the formulation of the polyurea resin coating material, it may lack sufficient elongation properties and may not satisfy the waterproofing standards (JIS A 6909 2014 Multi-layer finishing coating material Waterproof multi-layer coating material RS). In addition, depending on the construction conditions, such as when the surface condition of the substrate tile surface or joint is not smooth and has many irregularities, the thickness of the transparent reinforcing layer may locally exceed a certain level, resulting in a localized white cloudy appearance, which may impair the aesthetic appeal of the tiles.

[0008] Therefore, the problem that the present invention aims to solve is to provide an exterior wall tile waterproofing structure and exterior wall tile waterproofing method that has sufficient stretchability, does not cause clouding of the transparent intermediate coating even when the thickness of the transparent intermediate coating locally increases due to the surface condition of the substrate tile surface or joints, does not impair the aesthetic appearance of the tiles attached to the concrete skin of the building, has fewer construction steps than conventional methods, and has increased initial strength of the transparent intermediate coating, thereby having sufficient coating strength to exhibit waterproofing even when the temperature of the exterior wall surface of the building rises or the transparent intermediate coating deteriorates due to ultraviolet rays. [[MEANS FOR SOLVING THE PROBLEMS]]

[0009] In order to solve the above problem, the invention of claim 1 comprises applying a silicone acrylic resin primer containing an amino group-containing acrylic resin and epoxysilane to an exterior wall tile surface and joints to form a transparent primer layer, applying a transparent polyurea resin coating material onto the transparent primer layer to form a transparent intermediate coating layer, wherein the transparent polyurea resin coating material contains a non-yellowing isocyanate prepolymer which is an adduct and has a number average functional group number of 3.5 to 4.5, an alicyclic polyamine having only secondary amino groups, hydrophilic fine powder silica, a rheology control agent, a light stabilizer, an ultraviolet absorber, and a silane compound having two or more alkoxy groups bonded to silicon atoms in one molecule, applying an acrylic silicone resin coating material containing a light stabilizer and an ultraviolet absorber onto the transparent intermediate coating layer to form a transparent protective layer, wherein the blending amount of the silane compound in the polyurea resin coating material is more than 0.5 parts by weight and less than 5 parts by weight based on 100 parts by weight of the total polyurea resin coating material the law of nature, The non-yellowing isocyanate prepolymer consists of an aliphatic difunctional isocyanate and a polyhydric alcohol. Silane compounds having two or more alkoxy groups bonded to a silicon atom in one molecule are vinyltrimethoxysilane. , thereby providing an exterior wall tile waterproof structure.

[0012] Claim 2 the invention as described provides the exterior wall tile waterproof structure according to claim 1, wherein the light stabilizer is a hindered amine light stabilizer, and the ultraviolet absorber is a hydroxyphenyltriazine-based ultraviolet absorber or a benzotriazole-based ultraviolet absorber.

[0013] Claim 3 the invention as described is characterized in that the alicyclic polyamine is represented by Formula I: [[Chemical formula]] The characteristic feature is that the formula is one or more polyamines represented by (wherein X is an m-valence group obtained by removing primary amino groups from an organic polyamine with a number average molecular weight of 88 to 400 that is inert to an isocyanate group and contains m primary amino groups bonded to an alicyclic hydrocarbon, R1 and R2 are the same or different, and are organic groups having 1 to 18 carbon atoms, and m is at least an integer of 2) or claim 2 The following exterior wall tile waterproofing structure is provided.

[0014] Claim 4 The invention involves applying a silicone acrylic resin primer containing an amino group-containing acrylic resin and epoxy silane to the exterior wall tile surface and joints to form a transparent primer layer, and then applying a non-yellowing isocyanate prepolymer of the adduct body and a secondary grade on top of the transparent primer layer. A transparent polyurea resin coating material containing an alicyclic polyamine having only amino groups, hydrophilic fine silica powder, a rheology control agent, a light stabilizer, an ultraviolet absorber, and a silane compound having two or more alkoxy groups bonded to silicon atoms in one molecule is applied to form a transparent intermediate coating layer. A transparent protective layer is formed by applying an acrylic silicone resin coating material containing a light stabilizer and an ultraviolet absorber onto the transparent intermediate coating layer. The amount of silane compound in the aforementioned polyurea resin coating material is more than 0.5 parts by weight and less than 5 parts by weight out of 100 parts by weight of the entire polyurea resin coating material. the law of nature, The aforementioned non-yellowing isocyanate prepolymer consists of an aliphatic difunctional isocyanate and a polyhydric alcohol. The silane compound having two or more alkoxy groups bonded to a silicon atom in one molecule is vinyltrimethoxysilane. This invention provides a waterproofing method for exterior wall tiles that has certain characteristics.

[0017] Claim 5 The described invention is characterized in that the light stabilizer is a hindered amine-based light stabilizer, and the ultraviolet absorber is a hydroxyphenyltriazine-based ultraviolet absorber or a benzotriazole-based ultraviolet absorber. 4 This invention provides the exterior wall tile waterproofing method described above.

[0018] Claim 6The invention described is an alicyclic polyamine of formula I: [ka] The polyamine is characterized by being one or more polyamines represented by the formula (wherein X is an m-valence group obtained by removing primary amino groups from an organic polyamine with a number-average molecular weight of 88 to 400 that is inert to an isocyanate group and contains m primary amino groups bonded to an alicyclic hydrocarbon, R1 and R2 are the same or different, and are organic groups having 1 to 18 carbon atoms, and m is at least an integer of 2). 4 or claim 5 The exterior wall tile waterproofing method described To provide. [Effects of the Invention]

[0019] The exterior wall tile waterproofing structure described in claims 1 to 5 of the present invention has the effect of having excellent elongation properties (satisfying all elongation test standards specified in JIS A 6909 2014 Multi-layer finishing coatings Waterproof multi-layer coatings RS), and as a result, it has the effect of imparting waterproofing to the exterior wall tiles. Furthermore, since the polyurea resin coating material forming the transparent intermediate coating layer has higher strength compared to conventional acrylic resin emulsions, it has high elongation properties and degradation resistance even when the temperature of the wall surface rises and the temperature of the transparent intermediate coating layer rises, and since cracks do not occur in the coating film, it does not lose its waterproofing properties.

[0020] Furthermore, since the transparent intermediate coating contains a silane compound having two or more alkoxy groups bonded to silicon atoms in one molecule, even if a trace amount of moisture is present in the transparent intermediate coating, this moisture is stably removed by the silane compound. As a result, even if the transparent intermediate coating is applied thickly in areas with significant unevenness in the substrate's exterior wall tile surface and joints, micro-foaming due to trace amounts of moisture in the coating film does not occur, preventing clouding of the coating film. This has the effect of ensuring that the aesthetic appearance of the tiles attached to the concrete skin of the building is not impaired even after the exterior wall tile surface and joints are covered with the transparent intermediate coating. In addition, there is no reduction in coating film strength due to the occurrence of micro-foaming.

[0021] Furthermore, the polyurea resin coating material that forms the transparent intermediate coating layer is formed by the reaction of a non-yellowing isocyanate with an alicyclic polyamine having only secondary amino groups. The alicyclic polyamine used in this invention reacts more slowly than aliphatic amines, which cure very quickly, thus allowing it to be applied with a trowel, roller, or brush. In addition, compared to aromatic amines, which have a slow curing reaction and are generally used to ensure a longer pot life, the cured coating film is less prone to yellowing.

[0022] Furthermore, the transparent intermediate coating layer has a transparent protective layer formed by applying an acrylic silicone resin coating material. Since the transparent intermediate coating layer and the transparent protective layer contain light stabilizers and UV absorbers, the transparent intermediate coating layer and the transparent protective layer are less susceptible to deterioration from ultraviolet rays and other elements, resulting in less reduction in strength over the long term and ensuring reliable waterproofing of the exterior wall tiles over the long term.

[0023] Furthermore, since the transparent primer layer, transparent intermediate coat layer, and transparent protective layer applied on top of the tiles are all transparent, it has the effect of providing waterproofing to exterior wall tiles while maintaining the aesthetic appeal of the tiles.

[0024] Furthermore, the exterior wall tile waterproofing method described in claims 6 to 10 of the present invention has the effect of being able to be applied with a trowel or roller brush, in addition to the effects of the exterior wall tile waterproofing structure described in claim 1, because the coating material that forms the transparent intermediate coating layer on the transparent primer layer is a polyurea resin coating material consisting of a non-yellowing isocyanate prepolymer and an alicyclic polyamine having only secondary amino groups, and the cured coating film is less prone to yellowing.

[0025] Furthermore, the exterior wall tile waterproofing structure described in claim 3 of the present invention is particularly effective in removing minute amounts of moisture from the transparent intermediate coating layer because the silane compound having two or more alkoxy groups bonded to a silicon atom in one molecule of the exterior wall tile peeling prevention structure described in claim 1 or claim 2 is a compound having one silicon atom in one molecule and two or more alkoxy groups bonded to that silicon atom. As a result, the aesthetic appearance of the tiles is less likely to be impaired.

[0026] Furthermore, the exterior wall tile waterproofing method described in claim 8 of the present invention is particularly effective in removing minute amounts of moisture from the transparent intermediate coating layer because the silane compound having two or more alkoxy groups bonded to a silicon atom in one molecule, as described in claim 6 or claim 7, has one silicon atom in one molecule and two or more alkoxy groups bonded to that silicon atom. As a result, the aesthetic appearance of the tiles is less likely to be impaired.

[0027] Furthermore, the exterior wall tile waterproofing structure described in claim 4 of the present invention has the effect of preventing yellowing and deterioration of strength of the transparent intermediate coating layer and the transparent protective layer over a long period of time, particularly because the light stabilizer of the exterior wall tile waterproofing structure described in claims 1 to 3 is a hindered amine-based light stabilizer, and the ultraviolet absorber is a hydroxyphenyltriazine-based ultraviolet absorber or a benzotriazole-based ultraviolet absorber.

[0028] Furthermore, the exterior wall tile waterproofing method described in claim 9 of the present invention has the effect of preventing yellowing and deterioration of strength of the transparent intermediate coating layer and the transparent protective layer over a long period of time, particularly because the light stabilizer in the exterior wall tile waterproofing method described in claims 6 to 8 is a hindered amine-based light stabilizer, and the ultraviolet absorber is a hydroxyphenyltriazine-based ultraviolet absorber or a benzotriazole-based ultraviolet absorber. [Modes for carrying out the invention]

[0029] The present invention will be described in detail below.

[0030] The exterior wall tile waterproofing structure of the present invention is characterized in that a transparent primer layer is formed by applying a silicone acrylic resin primer containing an amino group-containing acrylic resin and epoxy silane to the exterior wall tile surface and joints; a transparent polyurea resin coating material is applied on the transparent primer layer to form a transparent intermediate coating layer by applying a transparent polyurea resin coating material containing an adduct body with a number average number of functional groups of 3.5 to 4.5, an alicyclic polyamine having only secondary amino groups, hydrophilic fine silica powder, a rheology control agent, a light stabilizer, an ultraviolet absorber, and a silane compound having two or more alkoxy groups bonded to silicon atoms in one molecule; and an acrylic silicone resin coating material containing a light stabilizer and an ultraviolet absorber is applied on the transparent intermediate coating layer to form a transparent protective layer. In addition to these, additives such as dispersants, defoamers, and diluents may be added to the silicone acrylic resin primer, polyurea resin coating material, and acrylic silicone resin coating material as needed.

[0031] First, we will describe in detail the silicone acrylic resin primer, polyurea resin coating material, and acrylic silicone resin coating material used in the exterior wall tile waterproofing structure described in claims 1 to 5 and the exterior wall tile waterproofing method described in claims 6 to 10.

[0032] <Silicone acrylic resin primer> For the silicone acrylic resin primer used to form the transparent primer layer in the present invention, it is preferable to use an acrylic resin in which part of the main chain or side chain is amine-modified as the amino group-containing acrylic resin. The acid value of the amine-modified acrylic resin is preferably 1.0 to 10.0 mgKOH / g, and the amine value is preferably 10 to 50 mgKOH / g. If the amine value is less than 10 mgKOH / g, the adhesion to the polyurea resin coating material that will be applied to the upper layer will be insufficient, and if the amine value is greater than 50 mgKOH / g, the amount of epoxysilane used as a curing agent will increase, resulting in higher costs. Note that the acid value refers to the measured value of the number of milligrams of potassium hydroxide equivalent to the molar equivalent of carboxyl groups in 1 g of polymer (solids), and the amine value refers to the measured value of the number of milligrams of potassium hydroxide equivalent to the molar equivalent of amino groups in 1 g of polymer (solids).

[0033] The glass transition temperature of the above-mentioned amino group-containing acrylic resin is preferably 10°C or higher and less than 50°C. If the glass transition temperature is below 10°C, the heat resistance is insufficient, and when the temperature of the transparent intermediate coating layer or the base tile becomes high in summer, the adhesion decreases, and if it exceeds 50°C, the adhesion to the tile decreases. The glass transition temperature referred to here means the value measured using a differential scanning calorimetry (DSC) in accordance with JIS K 7121-1987. An example of such a commercially available resin is ACRYDIC A-9521 (acid value: 3 mg KOH / g or less, amine value: 20 mg KOH / g, glass transition temperature: 15°C, manufactured by DIC Corporation, trade name).

[0034] Furthermore, the epoxysilane used in combination with the amino group-containing acrylic resin in the silicone acrylic resin primer that forms the transparent primer layer used in the present invention functions as a curing agent. The epoxy equivalent of such an epoxysilane curing agent is preferably in the range of 210 to 740 g / eq in terms of solid content. Note that epoxy equivalent is the theoretical value of the molecular weight of epoxysilane per functional group (epoxy group). If the epoxy equivalent is less than 210, the curing reaction is accelerated and workability is reduced, and if it exceeds 740, the heat resistance is insufficient, and adhesion decreases when the temperature of the transparent intermediate coating layer or the base tile becomes high in summer. Examples of commercially available epoxysilanes include ACRYDIC A-9585 (epoxy equivalent: 560 g / eq, manufactured by DIC Corporation, product name), ACRYDIC A-9585-BA (a product with only the solvent changed from A-9585, manufactured by DIC Corporation, product name), ACRYDIC FZ-521 (epoxy equivalent: 590 g / eq, manufactured by DIC Corporation, product name), and ACRYDIC FZ-523 (epoxy equivalent: 680-740 g / eq, manufactured by DIC Corporation, product name).

[0035] The blending ratio of epoxysilane to amino group-containing acrylic resin is determined as follows. First, the number of amino groups in 1 g of amino group-containing acrylic resin is determined by dividing the sum of the amine value (mg) and acid value (mg) by the molecular weight of KOH (mg). Next, the number of epoxy groups in 1 g of epoxysilane is determined by dividing 1 g by the epoxy equivalent. The approximate blending amounts of each are then determined so that the ratio of amino groups to epoxy groups is 1:1. After that, the optimal amount of epoxysilane by weight is determined by experimentally confirming the adhesion to the base tile and grout, and the adhesion between the silicone acrylic resin primer and the transparent intermediate coating layer described later. In this invention, 50% to 100% of the determined amount of epoxysilane by weight is preferred as the blending amount per 100 parts by weight of amino group-containing acrylic resin.

[0036] <Polyurea resin coating material> The polyurea resin coating material used to form the transparent intermediate coating layer in the present invention is characterized by comprising: a non-yellowing isocyanate prepolymer which is an adduct body and has a number average number of functional groups of 3.5 to 4.5; an alicyclic polyamine having only secondary amino groups; hydrophilic fine silica powder; a rheology control agent; a light stabilizer; an ultraviolet absorber; and a silane compound having two or more alkoxy groups bonded to silicon atoms in one molecule.

[0037] Non-yellowing isocyanate prepolymers can be made by prepolymerizing aliphatic bifunctional isocyanates such as hexamethylene diisocyanate (HDI), alicyclic bifunctional isocyanates such as isophorone diisocyanate (IPDI), or 4,4'-diphenylmethane diisocyanate (MDI) or 4,4'-methylenebis(cyclohexyl isocyanate) (hydrogenated MDI) with a polyhydric alcohol (adduct). Examples of such polyhydric alcohols include polycarbonate polyols, polyester polyols, polyether glycols, polycarbonate polyester polyols, polycaprolactone-modified polyols, and trimethylolpropane. Prepolymers made with polycaprolactone-modified polyols, polyether glycols, or trimethylolpropane are particularly preferred due to their excellent elongation properties.

[0038] The NCO weight percentage of the non-yellowing isocyanate prepolymer is preferably 5 to 20% by weight, and more preferably 10 to 15% by weight. Below 5% by weight, the coating strength will be insufficient; above 20% by weight, the elongation of the coating will decrease; below 10% by weight, the coating strength may be insufficient; above 15% by weight, the elongation of the coating may decrease, and the pot life when using this material in summer tends to be shorter. When using a non-yellowing isocyanate prepolymer alone, the NCO weight percentage of that non-yellowing isocyanate prepolymer should be within the above range; when using a mixture of two or more, the NCO weight percentage of the mixture should be within the above range; however, a non-yellowing isocyanate prepolymer with an NCO weight percentage outside the above range may also be used.

[0039] Furthermore, the number-average functional group count of the non-yellowing isocyanate prepolymer in the present invention is preferably 3.5 to 4.5. Within this range, the transparent intermediate coating layer exhibits excellent elongation properties (satisfying all elongation test standards specified in JIS A 6909 2014 Multi-layer finishing coatings Waterproof multi-layer coatings RS). Even if cracks occur on the tile surface or in the joints, the exterior wall tile waterproofing structure of the present invention will follow these cracks. In other words, no cracks will occur in the exterior wall tile waterproofing structure, and waterproofing can be reliably provided to the exterior wall tiles. The number-average functional group count is calculated using the following formula. Number-average functional group count = Number-average molecular weight × NCO% ÷ 42 (molecular weight of NCO group) ÷ 100

[0040] Examples of commercially available non-yellowing isocyanate prepolymers that can be used include Duranate E405-80T (HDI-based adduct prepolymer, adducted polyol: trimethylolpropane, caprolactone-modified polyol, solids content: 80% by weight, viscosity: 270 mPa·s / 25℃, NCO% by weight: 7.1%, number average molecular weight (Mn): 2600, number average number of functional groups: 4.4, manufactured by Asahi Kasei Corporation, trade name) and Duranate AE700-100 (HDI-based adduct prepolymer, adducted polyol: polypropylene glycol, solids content: 100% by weight, viscosity: 800 mPa·s / 25℃, NCO% by weight: 11.9%, number average molecular weight (Mn): 1340, number average number of functional groups: 3.8, manufactured by Asahi Kasei Corporation, trade name).

[0041] Alicyclic polyamines are polyamines in which at least one amino group, such as isophorone diamine, is directly bonded to a cyclohexane ring, etc., and amines having only secondary amino groups and no primary amino groups are used. The weight-average molecular weight (Mw, theoretical value) is preferably 300 to 1000. If it is less than 300, the pot life is shortened and workability is poor, and if it is greater than 1000, the reaction rate decreases, delaying the time to touch-dry and the rise of coating strength. Only by using alicyclic polyamines having only secondary amino groups can a sufficient pot life be ensured for applying the polyurea resin coating material with a trowel or roller brush, and furthermore, when used in combination with a non-yellowing isocyanate prepolymer, the cured coating film will not yellow under ultraviolet light.

[0042] The alicyclic polyamine is represented by the above formula I, where X, R1, R2, and m are one or more polyamines as described above. This alicyclic polyamine is a polyaspartate ester or polyaspartate, and m is preferably 2. Polyaspartate esters in which X represents a divalent hydrocarbon group having 6 to 30 carbon atoms, such as 4,4'-diaminodicyclohexylmethane (4,4'-methylenebis(cyclohexylamine)), 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane (4,4'-methylenebis(2-methylcyclohexylamine)), 1-amino-3,3,5-trimethyl-5-aminomethylcyclohexane, hexahydro- (containing at least 2,4-diaminotoluene or 2,6-diaminotoluene), isomeric C-monomethyldiaminodicyclohexylmethane, and a group obtained by removing a primary amino group from 3(4)-aminomethyl-1-methylcyclohexylamine, can be suitably used. In particular, compounds of formula I in which X represents a divalent hydrocarbon group that can be obtained by removing a primary amino group from 4,4'-diaminodicyclohexylmethane (4,4'-methylenebis(cyclohexylamine)) or 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane (4,4'-methylenebis(2-methylcyclohexylamine)) are more preferred.

[0043] The alicyclic polyamine represented by formula I preferably has R1 and R2 as methyl, ethyl, n-butyl, or 2-ethylhexyl, and is produced by reacting a primary polyamine represented by formula X-(-NH2)m with a maleic acid ester or fumaric acid ester represented by formula R1OOC-CH=CH-COOR2.

[0044] The alicyclic polyamine obtained by reacting 1 mole of 4,4'-methylenebiscyclohexylamine with 2 moles of diethyl maleate is supplied to the market as 4,4'-methylenebiscyclohexylamine-diethyl maleate adduct, with a weight-average molecular weight (Mw) of 548 (theoretical value) and a viscosity of 2000 mPa·s / 23℃. Similarly, the alicyclic polyamine obtained by reacting 1 mole of 4,4'-methylenebis(2-methylcyclohexylamine) with 2 moles of diethyl maleate is supplied to the market as 4,4'-methylenebis(2-methylcyclohexylamine)-diethyl maleate adduct, with a weight-average molecular weight (Mw) of 578 (theoretical value) and a viscosity of 2000 mPa·s / 23℃.

[0045] The equivalent ratio (NCO group / active hydrogen group) of the non-yellowing isocyanate prepolymer to the active hydrogen group of the alicyclic polyamine is preferably 0.8 to 1.2. If it is less than 0.8, the viscosity may increase rapidly after mixing the main agent and the curing agent, resulting in a shorter pot life. If it is greater than 1.2, the time to touch-dry and the onset of coating strength may be delayed.

[0046] The non-yellowing isocyanate prepolymer and the alicyclic polyamine are thoroughly mixed and used immediately before applying the polyurea resin coating material onto an already formed transparent primer layer.

[0047] Hydrophilic fine silica is a non-crystalline, finely powdered hydrophilic fumed silica with a specific surface area of ​​150-500 m² as measured by the BET method. 2 It can be used if it has a specific surface area of ​​150 m². 2 For amounts less than / g, sufficient thixotropy is not imparted, 500m 2At concentrations exceeding / g, the workability of applying the transparent undercoat layer with a roller brush decreases. Furthermore, the silanol group density of hydrophilic fine silica is 2SiOH / nm. 2 The above is desirable. A hydrophilic fine silica that satisfies these conditions is HDK-N20 (specific surface area (BET method): 170~230 g / m²). 2 , silanol group density: 2SiOH / nm 2 It is manufactured by Asahi Kasei Wacker Silicone Co., Ltd. (product name).

[0048] Furthermore, the rheology control agent is a thixotropic enhancer having free OH groups that form hydrogen bonds with the silanol groups on the particle surface of hydrophilic fine silica, thereby forming a three-dimensional structure with the silica particles. Polyhydroxycarboxylic acid amides are particularly suitable for use. A commercially available rheology control agent is BYK-405 (polyhydroxycarboxylic acid amide content: 51%, manufactured by Big Chemie Co., Ltd., trade name).

[0049] The polyurea resin coating material according to the present invention further contains a light stabilizer and an ultraviolet absorber, so that the strength of the transparent intermediate coating does not decrease even when exposed to ultraviolet light for a long period of time. A hindered amine-based light stabilizer can be used as the light stabilizer, and a hydroxyphenyltriazine-based ultraviolet absorber or a benzotriazole-based ultraviolet absorber can be used as the ultraviolet absorber. A commercially available hindered amine-based light stabilizer is TINUVIN 292 (chemical name: bis(1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, manufactured by BASF, trade name). A commercially available hydroxyphenyl triazine-based UV absorber is TINUVIN 400 (chemical name: reaction product of 2-(4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine-2-yl)-5-hydroxyphenyl and oxirane, manufactured by BASF, trade name). A commercially available benzotriazole-based UV absorber is TINUVIN 928 (chemical name: 2-(2H-benzotriazole-2-yl)-6-(1-methyl-1-phenylethyl)-4-(1,1,3,3-tetramethylbutyl)phenol, manufactured by BASF, trade name).

[0050] Furthermore, the polyurea resin coating material contains a silane compound having two or more alkoxy groups bonded to a silicon atom in one molecule.

[0051] A silane compound having two or more alkoxy groups bonded to a silicon atom in one molecule may be either a compound having one silicon atom in one molecule with two or more alkoxy groups bonded to that silicon atom, or an organopolysiloxane compound having two or more silicon atoms in one molecule, with a polysiloxane skeleton, and two or more alkoxy groups bonded to the silicon atom. However, the former type of silane compound is preferred.

[0052] Examples of silane compounds having one silicon atom in a molecule with two or more alkoxy groups bonded to the silicon atom include dialkoxysilanes such as dimethyldimethoxysilane, dimethyldiethoxysilane, diethyldimethoxysilane, diethyldiethoxysilane, diphenyldimethoxysilane, and diphenyldiethoxysilane; trialkoxysilanes such as methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, vinyltriethoxysilane, and vinyltrimethoxysilane; tetraalkoxysilanes such as tetramethoxysilane, tetraethoxysilane, and tetraisopropyloxysilane; hydrolysates of trialkoxysilanes and tetraalkoxysilanes; and (meth)acryloxyalkyltrialkoxysilanes such as γ-(meth)acryloxypropyltrimethoxysilane and γ-(meth)acryloxypropyltriethoxysilane. Among these, vinyltrimethoxysilane is preferred due to its availability and hydrolysis resistance. When vinyltrimethoxysilane is used, the amount to be blended is preferably more than 0.5 parts by weight and less than 5 parts by weight per 100 parts by weight of the total polyurea resin coating material. However, when using other silane compounds, the amount to be blended can be determined based on the aesthetic appearance of the underlying tile surface and the workability of the transparent intermediate coating layer when the polyurea resin coating material is applied to the underlying tile surface and joints and hardened.

[0053] Furthermore, in the polyurea resin coating material of the present invention, the absence of a silanol condensation catalyst further prevents damage to the aesthetic appearance of the base tile. Examples of the silanol condensation catalyst include organotin compounds such as tin octoate, tin neodecanoate, tin naphthenate, tin stearate, dibutyltin dioctoate, dibutyltin dilaurate, dioctyltin diversate, dibutyltin bistriethoxysilicate, dibutyltin dioleylmalate, dibutyltin diacetate, 1,1,3,3-tetrabutyl-1,3-dilauryloxycarbonyl-distanoxane, dibutyltin oxybisethoxysilicate, dibutyltin oxide, reaction products of dioctyltin salt and orasilicate ethyl, reaction products of dibutyltin salt and orasilicate ethyl, reaction products of dibutyltin oxide and phthalate ester, reaction products of dibutyltin oxide and maleate diester, and dibutyltin diacetylacetonate.

[0054] If a silanol condensation catalyst is included, the silane compound will decompose due to moisture, and the resulting silanol groups will condense to produce water again. The presence of this water may cause the transparent undercoat to become partially cloudy, potentially impairing the aesthetic appearance of the underlying tiles.

[0055] Furthermore, in the polyurea resin coating material of the present invention, the absence of reinforcing short fibers further prevents damage to the aesthetic appearance of the base tile. Examples of such reinforcing short fibers include vinylon, nylon, and glass short fibers with an average fiber length of 25 to 20,000 μm and a fiber diameter of 1 to 150 μm. Commercially available products include, for example, Milled Fiber EFDE-50-31 (glass short fiber, average fiber length: 50 μm, fiber diameter: 6 μm, surface treatment: silane-based, manufactured by Central Glass Fiber Co., Ltd., product name) and Tough Binder (nylon fiber, average fiber length: 3 mm, average fiber diameter: 28 μm, manufactured by Toray Amtec Co., Ltd., product name).

[0056] When reinforcing short fibers are included, the mixing and stirring of the main component and hardener of the polyurea resin coating material at the construction site can affect the process. Since this varies depending on the worker, if a large amount of trapped foam occurs, the reinforcing short fibers will capture the foam, causing it to remain in the coating film. As a result, the transparent reinforcing layer may become cloudy white, impairing the aesthetic appearance of the underlying tiles. In addition, compared to cases without reinforcing short fibers, the coating strength may be lower due to the large amount of foam remaining in the coating film. Furthermore, including reinforcing short fibers may result in a greater reduction in pot life during the summer months.

[0057] <Acrylic silicone resin coating material> The acrylic silicone resin coating material used to form the transparent protective layer according to the present invention comprises an acrylic silicone oligomer having alkoxysilyl groups as the main component, and a tin-based curing catalyst can be used as the curing agent. The main component and curing agent are uniformly mixed immediately before applying the acrylic silicone resin coating material onto the already formed transparent intermediate coating layer, and then applied using a roller brush or the like. The alkoxysilyl groups of the main component are crosslinked by the tin-based curing catalyst of the curing agent to form stable siloxane bonds, resulting in excellent durability.

[0058] The alkoxysilyl group content is preferably 2% to 30% by weight. Below 2% by weight, weather resistance decreases, and above 30% by weight, viscosity increases, reducing workability. A commercially available acrylic silicone oligomer containing alkoxysilyl groups is Kaneka Zemlac YC4383 (siloxane crosslinked reactive polymer, viscosity: 4000 mP·s / 23℃, alkoxysilyl group content: 15% by weight, manufactured by Kaneka Corporation, trade name). A commercially available tin-based curing catalyst is Kaneka Zemlac BT405Z (organotin compound, effective tin content: 1-2% by weight, manufactured by Kaneka Corporation, trade name) and Kaneka Zemlac ZT406Z (organotin compound, effective tin content: 1-2% by weight, manufactured by Kaneka Corporation, trade name).

[0059] The acrylic silicone resin coating material of the present invention contains a light stabilizer and an ultraviolet absorber, and the strength of the transparent intermediate coating layer does not decrease even when exposed to ultraviolet light for a long period of time. Hindered amine-based light stabilizers can be used as light stabilizers, and a commercially available hindered amine-based light stabilizer is TINUVIN 292 (bis(1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, manufactured by BASF, trade name). Hydroxyphenyl triazine-based UV absorbers or benzotriazole-based UV absorbers can be used as UV absorbers, and a commercially available hydroxyphenyl triazine-based UV absorber is TINUVIN 400 (2-(4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine-2-yl)-5-hydroxyphenyl and oxirane reaction product, manufactured by BASF, trade name). A commercially available benzotriazole-based UV absorber is TINUVIN 928 (chemical name; 2-(2H-benzotriazole-2-yl)-6-(1-methyl-1-phenylethyl)-4-(1,1,3,3-tetramethylbutyl)phenol, manufactured by BASF, trade name).

[0060] The following will provide a detailed explanation using examples and comparative examples. [Examples]

[0061] <Examples and Comparative Examples 1 to 5> ACRYDIC A-9521 was used as the amino group-containing acrylic resin and ACRYDIC A-9585 as the epoxy silane for the silicone acrylic resin primer forming the transparent primer layer. The main component and curing agent were prepared in the formulations shown in Table 1. The weight ratio of the main component to the curing agent was 13:1. These main components and curing agents were uniformly mixed to obtain the silicone acrylic resin primers of Example and Comparative Examples 1 to 5.

[0062] The polyurea resin coating material forming the transparent intermediate layer uses the above-mentioned 4,4'-methylenebiscyclohexylamine diethyl maleate adduct (weight-average molecular weight (Mw): 548 (theoretical value), viscosity: 2000 mP·s / 23℃) as alicyclic polyamine A, the above-mentioned 4,4'-methylenebis(2-methylcyclohexylamine) diethyl maleate adduct (weight-average molecular weight (Mw): 578 (theoretical value), viscosity: 2000 mP·s / 23℃) as alicyclic polyamine B, HDK-N20 as hydrophilic fine silica powder, BYK-405 as rheology control agent, TINUVIN292 as light stabilizer, TINUVIN400 as UV absorber, and GENIOSIL as a silane compound having two or more alkoxy groups bonded to silicon atoms in one molecule. XL-10 (vinyltrimethoxysilane, manufactured by Asahi Kasei Wacker Silicone Co., Ltd., product name) is used as the non-yellowing isocyanate prepolymer A, Duranate E405-80T as the non-yellowing isocyanate prepolymer B, Duranate AE700-100 as the non-yellowing isocyanate prepolymer C, and Duranate TSE-100 (HDI-based isocyanurate prepolymer, viscosity: 1650 mPa·s / 25℃, NCO wt%: 12.0%, number average molecular weight (Mn): 1920, number average number of functional groups: 5.5, Asahi Kasei Corporation) is used as the non-yellowing isocyanate prepolymer C. The company uses Duranate E402-100 (HDI-based adduct prepolymer, adducted polyol: caprolactone-modified polyol, solids content: 80% by weight, viscosity: 6000 mPa·s / 25℃, NCO% by weight: 8.5%, number average molecular weight (Mn): 1580, number average number of functional groups: 3.2, manufactured by Asahi Kasei Corporation, product name) as the non-yellowing isocyanate prepolymer D, and in addition, milled fiber EFDE-50-31 is used as reinforcing short fibers, and molecular sieve 5A powder (average particle size D) is used as a dehydrating agent. 50 Using a 6μm (manufactured by Union Showa Co., Ltd., trade name) acrylic defoaming agent, the main component and hardener were prepared in the formulations shown in Table 1. The weight ratio of the main component to the hardener was 3:4, and these main components and hardeners were used to obtain the polyurea resin coating materials of Example and Comparative Examples 1 to 5.

[0063] Kaneka Zemurac YC4383 was used as the acrylic silicone oligomer having an alkoxysilyl group for the acrylic silicone resin coating material that forms the transparent protective layer, TINUVIN292 as the light stabilizer, TINUVIN928 as the ultraviolet absorber, a silicone-based defoamer as the defoamer, Kaneka Zemurac ZT406Z as the curing catalyst, and turpentine thinner #50 as the petroleum-based diluent as the diluent. The main component and curing agent were prepared in the formulations shown in Table 1. The weight ratio of the main component to the curing agent was 2:1. Acrylic silicone resin coating materials of Examples and Comparative Examples 1 to 5 were obtained using these main components and curing agents.

[0064] <Comparative Example 6> The silicone acrylic resin primer from the above example was used as the coating material for forming the transparent primer layer, the acrylic silicone resin coating material from the above example was used as the coating material for forming the transparent protective layer, and a transparent acrylic emulsion (butyl acrylate / methyl methacrylate copolymer, viscosity 50 Pa·s / 20℃, TI value (JIS A 6024 thixotropic index): 5.7, containing 2% by weight of nylon short fibers (fiber length 5 mm)) with a resin solids content of 50% was used as the coating material for forming the transparent intermediate coating layer.

[0065] [Table 1]

[0066] <Evaluation Method> The above examples and comparative examples were evaluated as follows. Unless otherwise specified, the preparation, curing, and evaluation tests of the test specimens were carried out under conditions of 23°C and 50% RH.

[0067] <Mortar adhesion strength> The surface of a mortar test board (70 x 70 mm, 20 mm thick) conforming to JIS R 5201 10.4 was sanded, and the silicone acrylic resin primer of the example and comparative example was applied to the central 40 x 40 mm area of ​​the sanded surface at a rate of 0.12 kg / m². 2was applied and dried there. Thereafter, for Examples and Comparative Examples 1 to 5, a polyurea resin coating material was applied at an application rate of 0.4 kg / m 2 applied there, followed by 24 hours of curing, and an acrylic silicone resin coating material was further applied at an application rate of 0.08 kg / m 2 applied in two coats, followed by 14 days of curing to obtain test specimens. For Comparative Example 6, a transparent acrylic emulsion was applied onto a dried silicone acrylic resin primer at an application rate of 0.5 kg / m 2 applied there, and after drying, the same material was applied at an application rate of 0.8 kg / m 2 applied there, and after drying, the same material was applied again at an application rate of 0.8 kg / m 2 applied there and dried, then an acrylic silicone resin coating material was applied at an application rate of 0.08 kg / m 2 applied in two coats, followed by 14 days of curing to obtain test specimens. The adhesive strength (MPa) in a standard state of each test specimen was measured in accordance with JIS A 6909 7.9 Adhesive Strength Test. Since cohesive failure of the test plate occurred in all test specimens, the adhesive strength was defined as mortar adhesive strength (MPa).

[0068] The test specimens described above were allowed to stand for 10 days such that a portion less than 5 mm from the application surface was immersed in water, then dried at 50°C ± 3°C for 24 hours, and allowed to stand at 23°C and 50% RH for 24 hours. The adhesive strength (MPa) after water immersion of each test specimen was measured in accordance with JIS A 6909 7.9 Adhesive Strength Test. Since cohesive failure of the test plate occurred in all test specimens, the adhesive strength was defined as mortar adhesive strength (MPa).

[0069] <Tensile Strength> For Examples and Comparative Examples 1 to 5, the polyurea resin coating material was spread into a sheet form with a thickness of 1 mm, cured for 24 hours, and then the acrylic silicone resin coating material was applied at an application rate of 0.08 kg / m 2 applied in two coats, cured for 14 days, and molded into the shape of No. 2 dumbbell specimens specified in JIS K 6251 Tensile Testing Method for Vulcanized Rubber. For Comparative Example 6, a transparent acrylic emulsion was applied at an application rate of 0.5 kg / m 2 applied there, and after drying, the same material was applied at an application rate of 0.8 kg / m 2 applied there, and after drying, the same material was applied again at an application rate of 0.8 kg / m 2After applying and drying, apply acrylic silicone resin coating material at a rate of 0.08 kg / m². 2 The material was coated twice, cured for 14 days, and then molded into the same dumbbell shape. Subsequently, it was pulled at a tensile speed of 500 mm / min according to the same test method, and the strength at fracture was defined as the tensile strength (MPa). The test was conducted under conditions of 23°C and 60°C.

[0070] <Speed ​​Test> In the examples and comparative examples 1 to 5, a polyurea resin coating was spread in a sheet to a thickness of 1 mm, cured for 24 hours, and then an acrylic silicone resin coating was applied at a rate of 0.08 kg / m². 2 The material was applied in two coats and cured for 14 days, then molded into the No. 2 dumbbell shape specified in JIS K 6251 Tensile Test Method for Vulcanized Rubber. For Comparative Example 6, a transparent acrylic emulsion was applied at a rate of 0.5 kg / m² over a dried silicone acrylic resin primer. 2 Apply the material, and after drying, apply the same material again at a rate of 0.8 kg / m2, and after drying, apply the same material again at a rate of 0.8 kg / m2. 2 After applying and drying, apply acrylic silicone resin coating material at a rate of 0.08 kg / m². 2 The sample was coated twice, cured for 14 days, and molded into a No. 2 dumbbell shape as specified in JIS K 6251 Tensile Test Method for Vulcanized Rubber. In accordance with JIS A 6909 2014 7.26 Elongation Test, elongation tests were performed at standard temperature, at -10°C, after immersion in water, and after heating. In the standard temperature elongation test, samples with an elongation rate of 120% or more were evaluated as ○, and those with an elongation rate of less than 120% were evaluated as ×. In the -10°C elongation test, samples with an elongation rate of 20% or more were evaluated as ○, and those with an elongation rate of less than 20% were evaluated as ×. In the immersion test after immersion, samples with an elongation rate of 100% or more were evaluated as ○, and those with an elongation rate of less than 100% were evaluated as ×. In the heating elongation test, samples with an elongation rate of 100% or more were evaluated as ○, and those with an elongation rate of less than 100% were evaluated as ×.

[0071] <Degradation test during elongation> Using a sheet prepared in the same manner as in the elongation test described above, a No. 1 dumbbell-shaped test specimen was created and stretched until the distance between the 40 mm gauge marks was 60 mm. This state was held in place with a holder and left to stand for 24 hours, after which it was left to stand for 7 days in an environment of 80±2℃. After being removed to room temperature and left to stand for at least 4 hours, the specimen was visually inspected and evaluated as ○ if there was no fracture or cracking, and × if there was otherwise.

[0072] <Permeability Test> For a flexible board (400 x 200 mm, 4 mm thick) conforming to JIS A 5430, the silicone acrylic resin primers of the examples and comparative examples were applied at a rate of 0.12 kg / m². 2 The material was applied and dried. Subsequently, for the examples and comparative examples 1 to 5, the polyurea resin coating material was applied at a rate of 0.4 kg / m². 2 After applying the coating and allowing it to cure for 24 hours, an acrylic silicone resin coating material was applied at a rate of 0.08 kg / m². 2 The material was coated twice and cured for 14 days to prepare the test specimens. The water permeability of the prepared test specimens was measured in accordance with JIS A 6909 Water Permeability Test Method B. Specimens with a water permeability of 0.5 mL or less were evaluated as ○, and those with a water permeability exceeding 0.5 mL were evaluated as ×.

[0073] <UV resistance> For the examples and comparative examples 1 to 5, the polyurea resin coating was spread in a sheet to a thickness of 1 mm and cured for 24 hours, after which the acrylic silicone resin coating was applied at a rate of 0.08 kg / m². 2 The sample was then coated twice and cured for 14 days to prepare the test specimen. For Comparative Example 6, a transparent acrylic emulsion was first applied at a rate of 0.5 kg / m² to form a 2 mm thick sheet. 2 Apply the material, and after drying, apply the same material at a rate of 0.8 kg / m². 2 Apply the material, and after drying, apply the same material again at a rate of 0.8 kg / m². 2 After applying and drying, apply acrylic silicone resin coating material at a rate of 0.08 kg / m². 2The test specimens were coated twice, cured for 14 days, and then prepared as test specimens. Each test specimen was subjected to a Super UV Tester (Model: SUV-W151, manufactured by Iwasaki Electric Co., Ltd., irradiation conditions: water-cooled metal halide lamp used, temperature 63℃, humidity 50%, illuminance 100mW / cm²). 2 After continuous irradiation for 180 hours, the sample was molded into the shape of a No. 2 dumbbell as specified in JIS K 6251, the tensile test method for vulcanized rubber. Subsequently, the appearance was visually inspected, and at the same time, the sample was pulled at a tensile speed of 500 mm / min according to the same test method, and the strength at the break was defined as the tensile strength (MPa).

[0074] <Pot life> For the polyurea resin coatings of the Examples and Comparative Examples 1 to 5, the main agent and curing agent were each prepared at 23°C. Immediately after mixing the main agent and curing agent, the viscosity was measured using a Type B rotational viscometer No. 5 rotor at 20 rpm to determine the initial viscosity. Thereafter, the viscosity was measured every 5 minutes, and the time until the viscosity reached twice the initial viscosity was calculated as the pot life.

[0075] <Drip-stopping properties> Commercially available porcelain tiles, Aurora Pale 50-2T PL-100 (95 x 45 mm, 7 mm thick, Class I (porcelain), manufactured by Danto Co., Ltd., product name), are pre-attached to the surface of a dried concrete slab (300 x 300 mm, 60 mm thick) conforming to JIS A 5371 using commercially available epoxy resin adhesive, and the concrete slab is held vertically. The silicone acrylic resin primers of Examples and Comparative Examples 1 to 5 are applied at a rate of 0.12 kg / m². 2 After applying and drying the coating, apply a polyurea resin coating at a rate of 0.3 kg / m². 2 The coating was applied to the surface of porcelain tiles, and the degree of dripping was visually evaluated. The evaluation was as follows: no dripping occurred (○), slight dripping occurred (△), and dripping occurred throughout (×).

[0076] <Transparency> A glass plate (150 x 150 mm, 2 mm thick) was coated with the polyurea resin coating material of Example and Comparative Examples 1 to 5 at a rate of 0.5 kg / m². 2 or 1.0 kg / m 2The coating was applied, and the transparency of the cured coating was visually evaluated. A ○ was used to indicate high transparency, a △ to indicate slight cloudiness, and a × to indicate opacity.

[0077] <Application workability> Commercially available porcelain tiles, Aurora Pale 50-2T PL-100 (95 x 45 mm, 7 mm thick, Class I (porcelain), manufactured by Danto Co., Ltd., product name), are pre-applied to the surface of a dry concrete slab (300 x 300 mm, 60 mm thick) conforming to JIS A 5371 using commercially available epoxy resin adhesive. Silicone acrylic resin primers of Examples and Comparative Examples 1 to 5 are applied to the surface of the porcelain tiles at a rate of 0.12 kg / m². 2 After applying and drying the coating, apply the polyurea resin coating material using a trowel and roller brush at a rate of 0.2 kg / m². 2 The product was applied, and the ease of application was evaluated. The evaluation was as follows: ○ indicates that it could be easily applied using a trowel and roller brush; △ indicates that it could be applied with a trowel but not with a roller brush; and × indicates that it could not be applied with either a trowel or a roller brush.

[0078] <Evaluation Results> The evaluation results are shown in Table 2.

[0079] [Table 2]

Claims

1. A transparent primer layer is formed on the exterior wall tile surface and joints by applying a silicone acrylic resin primer containing amino group-containing acrylic resin and epoxysilane. On the transparent primer layer, a non-yellowing isocyanate prepolymer having an adduct body with an average number of functional groups of 3.5 to 4.5, an alicyclic polyamine having only secondary amino groups, hydrophilic fine silica powder, a rheology control agent, a light stabilizer, and an ultraviolet absorber are provided. A transparent polyurea resin coating material containing a silane compound having two or more alkoxy groups bonded to a silicon atom in one molecule is applied to form a transparent intermediate coating layer. A transparent protective layer is formed by applying an acrylic silicone resin coating material containing a light stabilizer and an ultraviolet absorber onto the transparent intermediate coating layer. The amount of silane compound in the aforementioned polyurea resin coating material is more than 0.5 parts by weight and less than 5 parts by weight of the total 100 parts by weight of the polyurea resin coating material. The aforementioned non-yellowing isocyanate prepolymer consists of an aliphatic difunctional isocyanate and a polyhydric alcohol. An exterior wall tile waterproofing structure characterized in that the silane compound having two or more alkoxy groups bonded to a silicon atom in one molecule is vinyltrimethoxysilane.

2. The exterior wall tile waterproofing structure according to Claim 1, characterized in that the light stabilizer is a hindered amine-based light stabilizer and the ultraviolet absorber is a hydroxyphenyltriazine-based ultraviolet absorber or a benzotriazole-based ultraviolet absorber.

3. The alicyclic polyamine is of formula I: 【Chemistry 1】 The exterior wall tile waterproofing structure according to claim 1 or 2, characterized by being one or more polyamines represented by the formula (wherein X is an m-valence group obtained by removing primary amino groups from an organic polyamine with a number average molecular weight of 88 to 400 that is inert to an isocyanate group and contains m primary amino groups bonded to an alicyclic hydrocarbon, R1 and R2 are the same or different, and are organic groups having 1 to 18 carbon atoms, and m is at least an integer of 2).

4. A transparent primer layer is formed by applying a silicone acrylic resin primer containing an amino group-containing acrylic resin and epoxysilane to the exterior wall tile surface and joints. A transparent polyurea resin coating material is applied onto the transparent primer layer, comprising a non-yellowing isocyanate prepolymer of the adduct body, an alicyclic polyamine having only secondary amino groups, hydrophilic fine silica powder, a rheology control agent, a light stabilizer, an ultraviolet absorber, and a silane compound having two or more alkoxy groups bonded to silicon atoms in one molecule, thereby forming a transparent intermediate coating layer. A transparent protective layer is formed by applying an acrylic silicone resin coating material containing a light stabilizer and an ultraviolet absorber onto the transparent intermediate coating layer. The amount of silane compound in the aforementioned polyurea resin coating material is more than 0.5 parts by weight and less than 5 parts by weight of the total 100 parts by weight of the polyurea resin coating material. The non-yellowing isocyanate prepolymer consists of an aliphatic difunctional isocyanate and a polyhydric alcohol. A waterproofing method for exterior wall tiles, characterized in that the silane compound having two or more alkoxy groups bonded to a silicon atom in one molecule is vinyltrimethoxysilane.

5. The exterior wall tile waterproofing method according to claim 4, characterized in that the light stabilizer is a hindered amine-based light stabilizer and the ultraviolet absorber is a hydroxyphenyltriazine-based ultraviolet absorber or a benzotriazole-based ultraviolet absorber.

6. The alicyclic polyamine is of formula I: 【Chemistry 1】 The exterior wall tile waterproofing method according to claim 4 or 5, characterized by comprising one or more polyamines represented by the formula (wherein X is an m-valence group obtained by removing primary amino groups from an organic polyamine with a number average molecular weight of 88 to 400 that is inert to an isocyanate group and contains m primary amino groups bonded to an alicyclic hydrocarbon, R1 and R2 are the same or different, and are organic groups having 1 to 18 carbon atoms, and m is at least an integer of 2).

Images