JP2006200325A - Composition of coating agent for tile - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a composition of coating agent, which is to be coated to the surface of tile and is gentle to the environment and capable of giving an excellent non-water-permeable performance to the tile. <P>SOLUTION: This is the composition of coating agent to be applied to the surface of the tile for giving the non-water-permeable performance to the tile, which contains a predetermined alkyl trialco xisilane (monoalkyl substitution product) and a predetermined dialkyl dialco xisilane (dialkyl substitution product) in an aqueous medium under the presence of water and hydrolysis catalyzer; a 0.01 to 0.1 weight percentage of organosiloxane copolymer (component A) obtained by co-condensation at a ratio of 30/70 to 70/30 in weight (monoalkylate/dialkylate); a 0.005 to 0.5 weight percentage of metallic oxide (component B) with a mean grain size of less than 500 nm having a photocatalytic activity; and a 0.01 to 0.5 weight percentage of a dispersion stabilizer (component C) comprising a predetermined tetra-alkyl ammonium hydride. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention is applied to various tiles such as clay tiles, cement tiles, slate tiles and the like mainly used as roofing materials, and the coating composition for tiles that can impart excellent water permeability and other performances to the tiles Related to things.

  When roofing a building using tiles as a roofing material, generally, a wooden field board is fixed to the rafters and the main building, and if necessary, the tile is fixed to the field board through a tile fixing member. It is constructed by.

  However, clay is used as a raw material, molded into a predetermined shape and then fired to produce clay tiles such as glazed roof tiles and glaze roof tiles, cement tiles manufactured using cement as a raw material, and fibers suitable for cement. Slate roof tiles, etc. that are manufactured using a mixture of slags as such are difficult to achieve complete impermeability by themselves, and when exposed to rainwater for a long time, even if they are glaze roof tiles, There is a problem that rainwater permeates into the main body and eventually reaches the base plate, rafters and purlins, and the base plate, rafters and purlins corrode over the years.

Therefore, some countermeasures for such a problem have been proposed in the past.
For example, paint research No. 135, pages 75-79 (Oct. 2000) uses a polyisocyanate-cured weak solvent-based undercoat paint using a silicon-modified acrylic polyol resin, and also a silicon-modified acrylic polyol resin. A silicon waterproof coating method suitable for slate roofing and cement roofing using a polyisocyanate-curing weak solvent-based topcoat has been proposed.

  JP-A-9-235,830 discloses that the surface of the fired clay roof tile contains potassium titanate fibers as a roof tile excellent in weather resistance, chemical resistance, salt water resistance, heat resistance, water repellency, and antifouling properties. A roof tile provided with one or two layers of a curable silicone resin coating, a manufacturing method thereof, and a construction method have been proposed.

  Furthermore, in JP-A-10-54,116, as a means for improving the field plate itself and preventing corrosion of the field plate, rafters, purlins, etc., a metal plate having corrosion resistance is used. Fixing bolts are welded to the base plate main body formed with a plurality of valleys in parallel with each other at a predetermined interval in the water gradient direction and the direction perpendicular to the water gradient direction on the top side of the peak portion on the surface side. There has been proposed a metal base plate that is fixedly protruded and has a mounting bolt protruded and fixed at a predetermined position on the back surface side by welding.

  Furthermore, JP-A-2004-108,006 discloses a sheet made of non-woven fabric containing pine resin, and is interposed between a waterproof material such as a roof tile and a base material such as a field board, and from rain and snow. Corrosion-resistant inner-sheets have been proposed that are used for the purpose of preventing corrosion and waterproofing of the base material.

Paint Research No.135, pp. 75-79 (Oct. 2000) JP-A-9-235,830 Japanese Patent Laid-Open No. 10-54,116 JP 2004-108,006

  However, these conventional measures include using paints containing organic resins and solvents, using expensive additives, forming the base plate itself with a metal plate with excellent corrosion resistance, and roof tiles. It is not always sufficient in terms of environmental hygiene, tile construction, economy, and the like, such as providing a separate corrosion-resistant inner sheet between the base plate and the base plate.

  Therefore, as a result of earnestly examining the environmentally friendly tile coating agent composition which is coated on the surface of the tile itself and exhibits the excellent water-impervious performance of the tile, the present inventors have found that a specific medium is contained in the aqueous medium. An organosiloxane copolymer obtained by hydrolysis and cocondensation of an alkyltrialkoxysilane and a dialkyldialkoxysilane, a predetermined metal oxide having photocatalytic activity, and a dispersion stabilizer comprising a tetraalkylammonium halide By using a coating agent composition dispersed at a predetermined ratio, it was found that excellent water-impervious performance can be imparted to the roof tile, and the present invention has been completed.

  Accordingly, an object of the present invention is to provide an environmentally friendly coating agent composition for roof tiles that can be coated on the surface of the roof tile itself to exhibit excellent water-impervious performance.

That is, this invention is a coating agent composition for apply | coating to the surface of a roof tile, and providing water impermeability to this roof tile, and the following general formula (1) in an aqueous medium
R ¹ Si (OR ² ) 3 (1)
(Wherein R ¹ represents a saturated or unsaturated hydrocarbon group having 1 to 4 carbon atoms, and R ² represents a saturated hydrocarbon group having 1 to 4 carbon atoms). (Monoalkyl-substituted product) and the following general formula (2)
R ³ R ⁴ Si (OR ⁵ ) 2 (2)
(Wherein R ³ and R ⁴ represent a saturated or unsaturated hydrocarbon group having 1 to 4 carbon atoms, and R ⁵ represents a saturated hydrocarbon group having 1 to 4 carbon atoms). Organosiloxane copolymer obtained by cocondensation of dialkoxysilane (dialkyl-substituted product) with water and hydrolysis catalyst at a weight ratio (monoalkyl / dialkyl) of 30/70 to 70/30 (Component A) 0.01 to 1.0% by weight, metal oxide having a photocatalytic activity and an average particle diameter of 500 nm or less (Component B) 0.005 to 0.5% by weight, and the following general formula (3)
(R ⁶ ) 4N ⁺ OH ⁻ (3)
(Wherein R ⁶ represents a saturated hydrocarbon group having 1 to 4 carbon atoms) and a dispersion stabilizer (component C) of 0.01 to 0.5% by weight comprising a tetraalkylammonium hydride represented by: It is a coating agent composition for tiles to contain.

  In the present invention, examples of the alkyltrialkoxysilane of the above general formula (1) used for preparing the organosiloxane copolymer of component A include methyltrimethoxysilane, ethyltrimethoxysilane, n- Propyltrimethoxysilane, iso-propyltrimethoxysilane, n-butyltrimethoxysilane, tert-butyltrimethoxysilane, isobutyltrimethoxysilane, methyltriethoxysilane, ethyltriethoxysilane, n-propyltriethoxysilane, iso- Propyltriethoxysilane, n-butyltriethoxysilane, tert-butyltriethoxysilane, isobutyltriethoxysilane, vinyltrimethoxysilane, epoxytrimethoxysilane, allyltrimethoxysilane, 3-butenyltrimethoxysilane, methacryloxide Limethoxysilane, methacryloxymethyltrimethoxysilane, acryloxyethoxytrimethoxysilane, acryloxypropyltrimethoxysilane, allylaminopropyltrimethoxysilane, acryloxypropyltrimexysilane, vinyltriethoxysilane, epoxytriethoxysilane, allyl Triethoxysilane, 3-butenyltriethoxysilane, methacryloxytriethoxysilane, methacryloxymethyltriethoxysilane, acryloxyethoxytriethoxysilane, vinyltripropoxysilane, epoxytripropoxysilane, allyltripropoxysilane, 3-butyl Tenenyl tripropoxy silane, methacryloxy tripropoxy silane, vinyl tributoxy silane, epoxy tributoxy silane, allyl tributoxy Silane, 3-butenyltributoxysilane, methacryloxytributoxysilane, 3-isocyanatopropyltriethoxysilane, N-methylaminopropyltrimethoxysilane, aminobutyltrimethoxysilane, aminobutyltriethoxysilane, aminotripropoxysilane Aminotributoxysilane, mercaptomethyltrimethoxysilane, mercaptomethyltriethoxysilane, mercaptomethyltripropoxysilane, mercaptomethyltributoxysilane, mercaptoethyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxy Silane, acetoxymethyltrimethoxysilane, acetoxyethyltrimethoxysilane, acetoxypropyltrimethoxysilane, acetoxymethyltrie Toxisilane, Acetoxyethyltriethoxysilane, N- (2-Aminoethyl) -3-aminopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 6-azidosulfonylhexyltriethoxysilane, N-methylaminopropyltrimethoxysilane Etc.

  Specific examples of the dialkyl dialkoxysilane of the above general formula (2) used for preparing the organosiloxane copolymer of Component A include dimethyldimethoxysilane, methylethyldimethoxysilane, diethimedimethoxysilane, Methyl n-propyldimethoxysilane, acetoxymethylmethyldimethoxysilane, acetoxyethyldimethoxysilane, acryloxypropylmethyldimethoxysilane, N- (2-aminoethyl) -3-aminoisobutylmethyldimethoxysilane, N- (2-aminoethyl) -3-Aminopropylmethyldimethoxysilane, 3-aminopropylmethyldiethoxysilane, bis (3-cyanopropyl) dimethoxysilane, isobutylmethyldimethoxysilane, mercaptomethylmethyldiethoxysilane, 3-mercaptopropylmethyldimethoxy Examples include silane and N-methylaminopropylmethyldimethoxysilane.

  Then, the organosiloxane copolymer of component A comprises an alkyltrialkoxysilane (monoalkyl substituted product) of the above general formula (1) and a dialkyl dialkoxysilane (dialkyl substituted product) of the above general formula (2) in water and It is prepared by co-condensation in the presence of a hydrolysis catalyst. At this time, the ratio of co-condensing the alkyltrialkoxysilane of the general formula (1) and the dialkyl dialkoxysilane of the general formula (2) The ratio (monoalkyl / dialkyl) is 20/80 to 80/20, preferably 30/70 to 70/30. If the co-condensation ratio is lower than 20/80, the peel strength is lowered. On the other hand, if it is higher than 80/20, sufficient water repellency and water impermeability cannot be obtained.

  Furthermore, as the hydrolysis catalyst used in preparing the organosiloxane copolymer of Component A, various acids, alkalis, metal compounds, and the like can be used. Examples of the acid include hydrochloric acid, nitric acid, sulfuric acid, fluorine, and the like. Illustrative examples include mineral acids such as hydrofluoric acid and phosphoric acid, organic acids such as formic acid, acetic acid, propionic acid, lactic acid and paratoluenesulfonic acid, solid acids such as zeolite and H-type molecular sieves, and acidic ion exchange resins. Examples of the alkali include sodium hydroxide, potassium hydroxide, calcium hydroxide, ammonia, and organic amines, and examples of the metal compound include dibutyltin dilaurate, dibutyltin dioctate, and dibutyltin. Organotin compounds such as diacetate, trimethoxyaluminum, triethoxyaluminum, Organoaluminum compounds such as isopropoxyaluminum, trisecondary butoxyaluminum, aluminum tris (acetylacetonate), aluminum monoacetylacetonate bis (ethylacetoacetate), aluminum tris (ethylacetoacetate), ethylacetoacetate aluminum diisopropylate, Organic titanium compounds such as tetraisopropoxy titanium (Ti (isoC3H7) 4), titanium tetrakis (acetylacetonate), titanium bis (butoxy) bis (acetylacetonate), tetraisopropoxy titanium, titanium tetra n-butoxide, Zirconium tetrakis (cetylacetonate), zirconium bis (butoxy) bis (acetylacetonate) and zirconium (isopropoxy) ) Organic zirconium compounds such as bis (acetylacetonate), zirconium tetra n-butoxide, organometallic compounds other than organosilicates or metal alkoxide compounds, boron such as trimethyl borate, triethyl borate, tri n-butyl borate, boric acid Examples thereof include phosphorus compounds such as compounds and trimethyl phosphate, trimethyl phosphate, triethyl phosphate, and triethyl phosphite. Of these, preferably, nitric acid, tetramethylammonium hydride, tetraisopropoxy titanium, triethyl borate and the like can be mentioned. These hydrolysis catalysts are preferably acids, alkalis, or metal compounds that do not react with alkyltrialkoxysilanes and dialkyldialkoxysilanes under anhydrous conditions in preparing the coating agent composition. . The hydrolysis catalyst is usually 0.0001% by weight or more and 1% by weight or less, preferably in a mixture of the alkyltrialkoxysilane of the general formula (1) and the dialkyl dialkoxysilane of the general formula (2). It is used in a proportion of 0.001% by weight or more and 0.1% by weight or less.

  In addition, the method for preparing the organosiloxane copolymer of component A is not particularly limited, but in consideration of storage stability, it is preferable to perform hydrolysis and cocondensation immediately before preparing the coating agent composition. Well, more preferably, an alkyltrialkoxysilane of the general formula (1), a dialkyldialkoxysilane of the general formula (2), and a hydrolysis catalyst that does not react with these alkyltrialkoxysilanes and dialkyldialkoxysilanes under anhydrous conditions Are mixed in advance under anhydrous conditions to prepare a mixture for preparing component A, and when preparing the coating composition, this mixture for preparing component A is added to an aqueous medium to prepare an organosiloxane copolymer of component A. It is good. Thus, by preparing in advance as a mixture for preparing component A, the alkyltrialkoxysilane of the general formula (1) and the dialkyldialkoxysilane of the general formula (2) are co-condensed uniformly during hydrolysis, and a high concentration There is an advantage that a very small amount of hydrolysis catalyst does not need to be added on site.

In the present invention, the metal oxide used as component B has photocatalytic activity and has an average particle size of 500 nm or less, preferably 50 nm or more and 200 nm or less. For example, titanium oxide (TiO ₂ ), iron oxide (Fe ₂ O ₃ ), tungsten oxide (WO ₃ ), zinc oxide (ZnO), and metal oxides such as strontium titanate (SrTiO ₃ ) can be mentioned. From the viewpoint of water solubility (elution with rainwater after film formation) and the like, anatase type titanium oxide is preferable. When the average particle diameter of the metal oxide having photocatalytic activity is larger than 500 nm, non-uniform film formation and reduced strength occur, and the problem of whitening after film formation also occurs.

  Furthermore, in the present invention, the dispersion stabilizer used as component C needs to be a tetraalkylammonium hydride represented by the general formula (3), specifically, tetramethylammonium hydride (TMAH), trimethylhydroxyl Examples include ethylammonium hydride (choline), methyltrihydroxyethylammonium hydride, dimethyldihydroxyethylammonium hydride, tetraethylammonium hydride, trimethylethylammonium hydride, tetrapropylammonium hydride, and tetrabutylammonium hydride. From the viewpoint that a high pH is desirable, TMAH and choline are preferable, and TMAH is more preferable.

  Furthermore, as an aqueous medium used to form a coating agent composition containing the organosiloxane copolymer of component A, the metal oxide having photocatalytic activity of component B, and the dispersion stabilizer of component C, representative examples are as follows. In particular, water such as tap water and industrial water can be mentioned. If it is necessary to adjust the drying speed in relation to humidity in the environment of application, the following agents may be added. Absent. For example, in order to increase the drying rate, alcohols, hydrocarbons, esters, and ketones are added. Examples of addition of alcohols include methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, acetylacetone alcohol, and the like. Examples of hydrocarbons that can be used include benzene, toluene, xylene, kerosene, and n-hexane. Examples of esters include methyl acetate, ethyl acetate, propyl acetate, butyl acetate, methyl acetoacetate, ethyl acetoacetate, and acetoacetate. Butyl acetate or the like can be used. Examples of ketones that can be used include acetone, methyl ethyl ketone, methyl isobutyl ketone, and acetyl acetone. Examples of ethers that can be used include ethyl ether, butyl ether, methoxyethanol, ethoxyethanol, dioxane, furan, and tetrahydrofuran. Conversely, when the drying rate is lowered, a glycol derivative is added. Examples of glycol derivatives include ethylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol, propylene glycol monomethyl ether, propylene glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, ethylene glycol monomethyl ether acetate, ethylene Examples include glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate, and propylene glycol monoethyl ether acetate. Among these solvents, alcohols, particularly C1-C3 methanol, ethanol, isopropanol, glycol derivatives of propylene glycol monomethyl ether and diethylene glycol monoethyl ether are easy to handle, water-soluble, and environmentally friendly. It is preferable from the viewpoint.

  In the coating agent composition of the present invention, the proportion of the organosiloxane copolymer of component A, the metal oxide having photocatalytic activity of component B, and the dispersion stabilizer of component C in the aqueous medium is as follows. 01 wt% or more and 1.0 wt% or less, preferably 0.04 wt% or more and 0.07 wt% or less, and component B is 0.005 wt% or more and 0.5 wt% or less, preferably 0.005 wt% or less. The content of the component C is 0.01% by weight or more and 0.03% by weight or less, and the component C is 0.01% by weight or more and 0.5% by weight or less, preferably 0.01% by weight or more and 0.04% by weight or less. When the proportion of component A is lower than 0.01% by weight, the water-proof and water-repellent properties are lowered. On the other hand, when the proportion is higher than 1.0% by weight, the stability over time is lowered (solution gelation, sedimentation, separation, etc. ) And high costs. On the other hand, when the proportion of component B is lower than 0.005% by weight, the catalytic activity efficiency is lowered. May decrease. Furthermore, when the proportion of component C is less than 0.01% by weight, there is a problem that the stability over time (gelation, sedimentation, separation, etc. of the solution) occurs. There arises a problem that time is required for expression.

  And about the method of preparing the coating agent composition of this invention, the organosiloxane copolymer of the component A in the aqueous medium finally, the metal oxide which has the photocatalytic activity of the component B, and the dispersion stabilizer of the component C Any method can be used as long as it can prepare a composition containing a predetermined ratio, but for reasons such as preventing separation and sedimentation after preparation as much as possible and promoting the expression of water repellency. It is preferable to adjust by the following method.

  That is, first, an alkyltrialkoxysilane of the general formula (1), a dialkyldialkoxysilane of the general formula (2), and a hydrolysis catalyst that does not react with these alkyltrialkoxysilanes and dialkyldialkoxysilanes under anhydrous conditions are prepared in advance. 20% by weight or more and 70% by weight or less, preferably 30% by weight or more and 60% by weight or more suitable for the mixing operation of the mixture for preparing component A prepared by mixing under anhydrous conditions and the metal oxide having the photocatalytic activity of component B % Of metal oxide dispersed in water (component B aqueous dispersion) and component C dispersion stabilizer in a proportion of not more than 10% and not more than 10% by weight and not more than 50% by weight, preferably 20%. Use a dispersion stabilizer aqueous solution (component C aqueous solution: for example, 25% by weight aqueous solution when the dispersion stabilizer is TMAH) dissolved in water in a proportion of not less than 30% by weight and not more than 30% by weight. First, the component A preparation mixture is first added to an aqueous medium in an amount appropriate for the mixing operation, and the alkyltrialkoxysilane of the general formula (1) and the dialkyldialkoxysilane of the general formula (2). Is then hydrolyzed and co-condensed to prepare an aqueous medium liquid of component A organosiloxane copolymer (component A aqueous medium liquid), and then component C aqueous solution is added to and mixed with component A aqueous medium liquid. Thereafter, the component B aqueous dispersion is added and mixed, and finally the aqueous medium is added to adjust the moisture, thereby preparing a coating agent composition.

  The tile coating agent composition of the present invention includes, in addition to the above components A to C, if necessary, pigments such as colored pigments and extender pigments, fillers, and other various types that can be blended into ordinary paints. Additives can be blended. The addition amount is not particularly limited, and may generally be selected as appropriate so long as the effect of the present invention is not affected. Examples of such additives include inorganic pigments such as titanium oxide, zinc oxide, carbon black, ferric oxide (bengala), lead chromate, yellow lead, yellow iron oxide, ocher, ultramarine, and cobalt green. And organic pigments such as azo pigments, azo pigments, naphthol pigments, pyrazolone pigments, anthraquinone pigments, perylene pigments, quinacridone pigments, disazo pigments, isoindolinone pigments, benzimidazole pigments, phthalocyanine pigments, and quinophthalone pigments. It is also possible to use extender pigments such as heavy calcium carbonate, clay, kaolin, talc, precipitated barium sulfate, barium carbonate, white carbon, diatomaceous earth. Furthermore, as various additives, pigment dispersants for dispersing these pigments, anti-settling agents, anti-sagging agents, matting agents, plasticizers, antifoaming agents, leveling agents, anti-repellency agents, adhesion improvers , Antiseptics, algae inhibitors, antibacterial agents, deodorants, UV absorbers, and the like, and a small amount can be added and used. The amount of these additives to be added is not particularly limited as long as the amount of the additive that exhibits the effect of the target additive is exhibited. The method of blending these additives is not limited, and all components A to C may be blended and added after one component, or each component such as alkyl silicate, water, organic solvent, etc., which is easy to dissolve or disperse. You may add and use.

In order to impart water impermeability to various roof tiles using the roof tile coating composition of the present invention, the roof tile coating composition is formed by, for example, shower coating, spray coating, dip coating, spin coating, or the like. The material may be applied to the surface of the roof tile and dried by natural drying, forced drying using a dryer, or other suitable means. The coating amount at this time also depends on the solid content concentration in the coating composition. Although it is different, it is usually 100 g / m ² or more and 500 g / m ² or less, preferably 200 g / m ² or more and 300 g / m ² or less in terms of solid content.

  The tile coating agent composition of the present invention can exhibit excellent water-impervious performance to the tile by coating the surface of the tile without using an organic resin or solvent, and has photocatalytic activity. Since the metal oxide is added, it is environmentally friendly and excellent in terms of environmental hygiene, tile construction, economy, and the like.

  Hereinafter, preferred embodiments of the present invention will be described in detail based on examples and comparative examples.

[Examples 1 and 2 and Comparative Examples 1 to 4]
To a 1/1 weight ratio mixture of methyltrimethoxysilane and dimethyldimethoxysilane, 0.03% by weight of tetraisopropoxytitanium is added as a hydrolysis catalyst that does not react with these methyltrimethoxysilane and dimethyldimethoxysilane under anhydrous conditions. Thus, a component A preparation mixture for preparing the component A organosiloxane copolymer was obtained.

Also, an aqueous dispersion of anatase-type titanium oxide (TiO ₂ ) having an average particle size of 80 nm as a metal oxide having photocatalytic activity {TiO ₂ aqueous dispersion (component B aqueous dispersion)} (trade name: Sunecoat manufactured by TAM Network Co., Ltd.) , TiO ₂ concentration 30 wt%), TMAH aqueous solution (component C aqueous solution, TMAH concentration 25 wt%) or triethanolamine as a dispersion stabilizer, and tap water as an aqueous medium for preparing a coating agent composition Water was used.

  In a mixing vessel equipped with a stirrer, 50 kg of tap water corresponding to about 1/10 of the total amount of water used (500 kg) is added, and stirred at room temperature so that the concentration of component A finally becomes the concentration shown in Table 1. Below, the mixture for preparing component A was added and stirred for 10 minutes to react.

  After completion of the reaction, the TMAH aqueous solution or triethanolamine is added to the mixing vessel with stirring at room temperature so that the concentration of component C finally becomes the concentration shown in Table 1, and then the concentration of component B is finalized. Specifically, the above TiO2 aqueous dispersion was added with stirring at room temperature so that the concentrations shown in Table 1 were added, and tap water was added so as to reach the total amount of water used with stirring at room temperature. 2 and the coating agent composition of Comparative Examples 1-4 were obtained.

With respect to the coating agent compositions of Examples 1 and 2 and Comparative Examples 1 to 4 thus obtained, dispersion stability, water repellency, and water permeability were examined.
About dispersion stability, each coating agent composition was put into a beaker, a time-dependent change was examined visually, and time (hr) until precipitation of titanium oxide occurred was measured.

For water repellency test, glass plate (100mm x 70mm x 1.5mm size blue plate glass) and tile test piece (70mm x 70mm x 14mm size unglazed Sanshu tile (glaze tile) as base materials. , Toyo Tile Industry Co., Ltd., trade name: Urban or Trad], the glass plate was immersed in the coating composition for 60 seconds, and then pulled up and dried at room temperature to apply the coating composition and repel A water test piece is prepared, and a clay repellent test piece is prepared by applying a coating agent composition by dripping at a rate of 244.9 g / m ^{2 on} the surface of the unglazed roof tile and drying at room temperature. Then, 0.5 g of water droplets were dropped on the surface of each water-repellent test piece, and the height (mm) of the water droplet generated on the surface of the water-repellent test piece was measured.

Further, for the non-permeability test, the same tile test piece as used in the above water repellency test is used as the base material in accordance with the method of JIS A5423, and the water level drop (mm) after 24 hours is measured. Was done.
The results are shown in Table 1.
In Comparative Example 5, the water impermeability of the tile test piece itself was examined without performing the surface treatment with the coating agent composition. The results are also shown in Table 1.

  The tile coating composition of the present invention is applied to various tiles such as clay tiles, cement tiles, and slate tiles mainly used as a roofing material, and can exhibit excellent water-impervious performance to these tiles. It is environmentally friendly and economical, and has high industrial value.

Claims (5)

It is a coating agent composition that is applied to the surface of a tile to impart water impermeability to the tile, and in an aqueous medium,
Component A: The following general formula (1)
R ¹ Si (OR ² ) 3 (1)
(Wherein R ¹ represents a saturated or unsaturated hydrocarbon group having 1 to 4 carbon atoms, and R ² represents a saturated hydrocarbon group having 1 to 4 carbon atoms). (Monoalkyl-substituted product) and the following general formula (2)
R ³ R ⁴ Si (OR ⁵ ) 2 (2)
(Wherein R ³ and R ⁴ represent a saturated or unsaturated hydrocarbon group having 1 to 4 carbon atoms, and R ⁵ represents a saturated hydrocarbon group having 1 to 4 carbon atoms). Organosiloxane copolymer obtained by cocondensation of dialkoxysilane (dialkyl-substituted product) with water and hydrolysis catalyst at a weight ratio (monoalkyl / dialkyl) of 30/70 to 70/30 0.01 to 1.0% by weight;
Component B: 0.005 to 0.5% by weight of a metal oxide having a photocatalytic activity and an average particle diameter of 500 nm or less;
Component C: The following general formula (3)
(R ⁶ ) 4N ⁺ OH ⁻ (3)
(Wherein R ⁶ represents a saturated hydrocarbon group having 1 to 4 carbon atoms) and a dispersion stabilizer comprising tetraalkylammonium hydride represented by the formula 0.01 to 0.5% by weight. A coating composition for roof tiles.   The roofing agent composition according to claim 1, wherein the hydrolysis catalyst is an acid, an alkali, or a metal compound that does not react with alkyltrialkoxysilane and dialkyldialkoxysilane under anhydrous conditions.   The roofing agent composition according to claim 1 or 2, wherein the metal oxide of component B is anatase-type titanium oxide.   The roofing agent composition according to any one of claims 1 to 3, wherein the dispersion stabilizer of Component C is tetramethylammonium hydride (TMAH).   The roof tile coating composition according to any one of claims 1 to 4, wherein the roof tile is a clay roof tile.