JP6649797B2 - Coating method - Google Patents

Description

  The present invention relates to a novel method for forming a coating on inorganic materials such as concrete and cement mortar.

  Conventionally used as a base material for buildings and civil engineering structures, concrete, cement mortar, and other inorganic materials are coated with a permeable water-absorbing material as a method of imparting water-absorbing properties and improving durability. Is widely used.

  The permeable water absorption preventing material penetrates into an inorganic material to form a water repellent layer. Therefore, by applying such a permeable water-absorbing preventive material, the penetration of water or carbon dioxide gas from the outside into the base material is blocked, the strength of the base material is prevented from lowering due to neutralization, and the base material is further prevented. An effect of suppressing corrosion of the steel frame or the reinforcing bar existing inside can be exhibited. Further, it is possible to prevent the occurrence of efflorescence on the surface layer of the base material due to the migration of the calcium component inside the base material.

  As such a permeable water absorption preventing material, those containing a silane compound as a main component (for example, Patent Document 1) are known. However, simply applying such a permeable water-absorbing preventive material may not provide sufficient water repellency and water-absorbing preventive properties, and there is room for practical improvement.

  In Patent Document 2, a water-repellent waterproof material (undercoat material) of a solvent type is applied to the concrete surface, and a waterproof material (intermediate material) made of an emulsion-type transparent synthetic resin is applied to the surface, and further another waterproof material is provided. (Top coat material) is described. According to such a method, it is expected that the water absorption prevention property of the concrete surface is improved and the durability is enhanced.

  However, in the method of Patent Document 2, the adhesion of the emulsion-based waterproofing material becomes insufficient, and there is a possibility that desired effects in water absorption prevention, durability and the like may not be obtained.

JP-A-63-256581 JP 2002-89006 A

  The present invention has been made in view of such problems, and has as its object to provide a method for forming a coating film capable of imparting excellent water absorption prevention and durability to an inorganic material.

  In order to solve such a problem, the present inventors have made intensive studies and, as a result, conceived a method of applying a permeable water-absorbing prevention material as a first step and then applying a specific coating material as a second step. Thus, the present invention has been completed.

That is, the film forming method of the present invention has the following features.
1. A method for forming a film on an inorganic material,
For the surface of the inorganic material,
After applying a permeable water absorption preventing material as the first step,
As a second step, a coating material containing a synthetic resin emulsion (excluding those having a pigment volume concentration of 30% or more) is applied,
The synthetic resin emulsion, as a monomer constituting the synthetic resin,
The glass transition temperature of the homopolymer 50 ° C. or higher, the solubility parameter is 9.5 or less (meth) acrylic acid alkyl esters seen including,
The method for forming a film, wherein the alkyl (meth) acrylate contains cyclohexyl methacrylate .
2. The synthetic resin emulsion has a glass transition temperature of 10 to 60 ° C. The method for forming a film according to the above.
3. The synthetic resin emulsion has an average particle diameter of 120 nm or less. Or 2. The method for forming a film according to the above.
4. The synthetic resin emulsion is a silicone-modified acrylic resin emulsion. ~ 3. The method for forming a film according to any one of the above.
5. The content of the alkyl (meth) acrylate in the solid content of the synthetic resin emulsion is 3 to 70% by weight. ~ 4. The method for forming a film according to any one of the above.

  In the method of forming a coating film of the present invention, the first step is to apply a permeable water-absorbing material to the surface of an inorganic material, and then the second step is to apply a coating material containing a specific synthetic resin emulsion. In addition, it is possible to form a coating that imparts excellent water absorption prevention properties and durability to the inorganic material.

  Hereinafter, embodiments for carrying out the present invention will be described.

In the method of forming a film of the present invention, a permeable water-absorbing preventive material is applied to the surface of an inorganic material as a first step, and then a specific coating material is applied as a second step to form a film.
<Inorganic material>
The inorganic material forms a surface of a building, a civil engineering structure, or the like. Examples of such a substrate include concrete, mortar, siding board, extruded board, gypsum board, perlite board, brick, tile and the like. These substrates may be those having a coating already formed on the surface. The present invention is particularly preferably applied to a concrete surface such as a concrete wall surface. Such a concrete surface is usually prepared by mixing and mixing cement, water, aggregate, and an admixture material in an appropriate ratio and mixing, and then poured into a formwork or a predetermined place, cured, and demolded. It is obtained by this. The present invention can be applied to either a newly installed concrete surface or an aged concrete surface.

Note that, in the present invention, prior to the first step, a treatment such as washing may be performed on the inorganic material. For the cleaning treatment, a method of applying various cleaning agents to the inorganic material and then washing with water may be employed.

<First step>
The permeable water-absorbing preventive material of the first step in the present invention can be used without particular limitation as long as it is a material capable of exhibiting a water-absorbing preventing effect. For example, silicone resin, acrylic resin, urethane resin, unsaturated polyester resin, etc. Resin-based osmotic water-absorbing material containing as an ingredient; siliconate-based osmotic water-absorbing material containing an alkylsiliconate compound as a main component; silane-based permeable water-absorbing material containing a hydrolyzable silane compound and / or a condensate thereof as a main component Materials. In the present invention, a silane-based osmotic water-absorbing material can be preferably used. Examples of the silane-based osmotic water-absorbing material include, for example, organoalkoxysilane compounds, organoacetoxysilane compounds, organohalogensilane compounds, organodisilane compounds, organosilanecarboxylic acid compounds, organosilanethiol compounds, organosilicon isocyanate compounds, and organosilicon compounds. Isothianate compounds and compounds containing at least one selected from condensates thereof are exemplified.

The permeable water absorption preventing material is a solution in which the above-mentioned components are dissolved or dispersed in a medium, and may be a material in which the above components are dispersed by an emulsifier or the like. The medium in the permeable water absorption preventing material is not particularly limited, and a strong solvent based on an aromatic hydrocarbon solvent, a weak solvent based on an aliphatic hydrocarbon solvent, and water as a main component Although various forms such as an aqueous system can be used, in the present invention, a weak solvent system can be particularly preferably used. The solvent serving as the main component may be contained in each medium in an amount of 50% by weight or more (preferably 70% by weight or more).

  In such a permeable water absorption preventing material, the content ratio of the compound serving as the main component is preferably 0.1 to 50% by weight (more preferably 1 to 30% by weight, further preferably 2 to 20% by weight). is there. In such a range, a sufficient water absorption preventing effect can be exhibited.

In the present invention, in particular, as a compound serving as a main component, an alkylalkoxysilane compound having an alkyl group having 1 to 18 carbon atoms is 0.1 to 50% by weight (more preferably 1 to 30% by weight, and still more preferably 2 to 30% by weight). 20% by weight). Such an alkylalkoxysilane compound is a compound in which an alkyl group and an alkoxysilyl group are bonded to a silicon atom, and for example, a compound represented by the following formula (1) and / or a condensate thereof can be used.
R ¹ -Si (OR ² ) ₃ (1)
(In the formula, R ¹ and R ² represent an alkyl group. R ¹ has 1 to 18 carbon atoms.)

  Specifically, examples of the alkylalkoxysilane include methyltrimethoxysilane, methyltriethoxysilane, methyltripropoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, propyltrimethoxysilane, propyltriethoxysilane, and butyltrimethoxysilane. Silane, butyltriethoxysilane, pentyltrimethoxysilane, pentyltriethoxysilane, hexyltrimethoxysilane, hexyltriethoxysilane, heptyltrimethoxysilane, heptyltriethoxysilane, octyltrimethoxysilane, octyltriethoxysilane, nonyltrimethoxy Silane, nonyltriethoxysilane, decyltrimethoxysilane, decyltriethoxysilane, undecyltrimethoxysilane, undecyltrie Xysilane, dodecyltrimethoxysilane, dodecyltriethoxysilane, tridecyltrimethoxysilane, tridecyltriethoxysilane, tetradecyltrimethoxysilane, tetradecyltriethoxysilane, pentadecyltrimethoxysilane, pentadecyltriethoxysilane, hexadecyl Trimethoxysilane, hexadecyltriethoxysilane, heptadecyltrimethoxysilane, heptadecyltriethoxysilane, octadecyltrimethoxysilane, octadecyltriethoxysilane and the like can be mentioned. As these condensates, those having an average degree of condensation of about 1 to 10 can be used. These can be used alone or in combination of two or more.

As the alkylalkoxysilane compound, one having an alkyl group R ¹ of ¹ to 18 (preferably 3 to 12, more preferably 5 to 8) is used. The alkyl group may be partially substituted with halogen or the like. When the number of carbon atoms of the alkyl group falls within such a range, it is possible to enhance the water absorption preventing property. The alkoxyl group in the alkoxysilane compound, the number of carbon atoms (number of carbon atoms in the R ²⁾ may be used those having 1 to 8 (preferably 1 to 4, more preferably 1 to 2).

  In such a permeable water absorption preventing material, it is desirable that the resin component is not mixed too much, and that the content ratio is lower than that of the alkylalkoxysilane compound in order to sufficiently exert the action of the alkylalkoxysilane compound. The content ratio of the resin component (solid content) in the permeable water absorption preventing material is preferably less than 20% by weight (more preferably 10% by weight or less), and a form containing no resin component is also suitable.

  The osmotic water-absorbing material is, for example, a coloring agent, a thickening agent, a wetting agent, an antifreezing agent, a preservative, an antifungal agent, an anti-algal agent, an antibacterial agent, and a dispersant within a range not significantly impairing the effects of the present invention. , An antifoaming agent, a resin, an ultraviolet absorber, an antioxidant, a catalyst and the like. The permeable water absorption preventing material can be manufactured by uniformly mixing the above-mentioned components by a common method.

In the first step, such a permeable water-absorbing material is uniformly applied to a substrate. The application device is not particularly limited, and a known application device such as a brush, a spray, a roller, or a coater can be used. The required amount when applying the permeable water absorption preventing material may be appropriately set in consideration of the type and state of the base material, etc., but is preferably 30 to 500 g / m ² (more preferably 80 to 400 g / m ² ). ² ) about. The application and drying of the permeable water-absorbing preventive material may preferably be performed at normal temperature (0 to 40 ° C). In the present invention, after the osmotic water-absorbing material is dried, coating in the next step can be performed. The interval between the steps is usually from 1 hour to 10 days, preferably from 3 hours to 7 days.

<Second step>
As the coating material in the second step, a material containing a specific synthetic resin emulsion is used. The synthetic resin emulsion in the coating material has, as monomers constituting the synthetic resin, a homopolymer having a glass transition temperature (hereinafter, also referred to as “Tg”) of 50 ° C. or higher (preferably 60 to 120 ° C.) and a solubility parameter (hereinafter, referred to as “Tg”). (Meth) acrylic acid alkyl ester (A) (hereinafter also referred to as "component (A)") having an "sp value" of 9.5 or less (preferably 6 to 9.5). By applying a coating material containing such a component, excellent performance can be exhibited in adhesion to the above-described permeable water absorption preventing material, and the durability and the like of the inorganic material can be increased. In the present invention, the alkyl acrylate and the alkyl methacrylate are collectively referred to as an alkyl (meth) acrylate.

Examples of the component (A) of the present invention include tert-butyl methacrylate (Tg: 107 ° C, sp value: 9.07), cyclohexyl methacrylate (Tg: 83 ° C, sp value: 7.44), and the like. . Examples of the alkyl (meth) acrylate other than the component (A) include methyl methacrylate (Tg: 105 ° C, sp value: 9.93), ethyl acrylate (-20 ° C, sp value: 10.2), n -Butyl acrylate (Tg: -56 ° C, sp value: 9.77), n-butyl methacrylate (Tg: 20 ° C, sp value: 9.45), 2-ethylhexyl acrylate (Tg: -70 ° C, sp value: 9.22). The glass transition temperature of the homopolymer can be measured by DSC (differential scanning calorimetry). The solubility parameter is described in “POLYMER ENGINEERING AND SCIENCE”, Vol. 14, No. 2, p. It is a value calculated by the method described in 147-154.

  The content of the component (A) may be 3 to 70% by weight (more preferably 5 to 50% by weight, and still more preferably 8 to 40% by weight) in the solid content of the synthetic resin emulsion of the present invention. preferable. When the content is within such a range, excellent performance is exhibited in adhesion to the above-described permeable water absorption preventing material, and the durability and the like of the inorganic material can be increased.

Further, the glass transition temperature of the synthetic resin emulsion can be adjusted by selecting the type of the monomer, the mixing ratio, and the like. The glass transition temperature may be appropriately set in consideration of the final required performance and the like, but is preferably from 10 to 60 ° C (more preferably from 15 to 55 ° C) in the present invention. In such a case, the effects of the present invention can be further enhanced. In addition, the glass transition temperature of the synthetic resin emulsion can be obtained by the Fox calculation formula.

  Further, the synthetic resin emulsion preferably has an average particle size of 120 nm or less (more preferably 30 nm or more and 100 nm or less). In such a case, the effects of the present invention can be further enhanced. The average particle diameter can be measured by a dynamic light scattering method.

The synthetic resin emulsion of the present invention is not particularly limited as long as it satisfies the above-mentioned conditions. Emulsions and the like, or composites thereof, and the like, and one or more of these can be used.

The synthetic resin emulsion of the present invention is preferably a silicone-modified acrylic resin emulsion. The silicone-modified acrylic resin emulsion is obtained by using a reactive silyl group-containing compound as an essential component. By using a silicone-modified acrylic resin emulsion, adhesion, durability, etc. can be improved, and a coating film with good stain resistance, weather resistance, yellowing resistance, water resistance, chemical resistance, etc. can be formed. Can be.

In the present invention, it is preferable that the silicone-modified acrylic resin emulsion contains, for example, the component (A) as a monomer component and further satisfies any of the following conditions (1) to (4).
(1) Synthetic resin emulsion containing a reactive silyl group-containing monomer as a monomer component (2) At least one or more monomers selected from a reactive silyl group-containing monomer, a hydroxyl group-containing monomer and a carboxyl group-containing monomer as a monomer component A synthetic resin emulsion obtained by adding a silane compound to a resin,
(3) a synthetic resin emulsion obtained by reacting a functional group in the resin with a silane coupling agent having a functional group capable of reacting with the functional group;
(4) Synthetic resin emulsions obtained by reacting a functional group in a resin with a silane coupling agent having a functional group capable of reacting with the functional group, and further adding a silane compound.

Examples of the reactive silyl group include those in which an alkoxyl group, a phenoxy group, a mercapto group, an amino group, a halogen, and the like are bonded to a silicon atom. In the present invention, an alkoxysilyl group in which an alkoxyl group is bonded to a silicon atom is preferable.

The reactive silyl group-containing monomer in the above (1) and (2) is a compound containing a reactive silyl group and a polymerizable double bond. For example, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltri-n- Butoxysilane, vinyltris (β-methoxyethoxy) silane, allyltrimethoxysilane, trimethoxysilylethylvinylether, triethoxysilylethylvinylether, trimethoxysilylpropylvinylether, triethoxysilylpropylvinylether, γ- (meth) acryloyloxypropyltriethyl Methoxysilane, γ- (meth) acryloyloxypropyltriethoxysilane, γ- (meth) acryloyloxypropylmethyldimethoxysilane, vinylmethyldimethoxysilane, methyldimethoxysilyl ester Vinyl ether, and methyl dimethoxy silyl propyl vinyl ether and the like, can be used one or two or more thereof.

Examples of the hydroxyl group-containing monomer in the above (2) include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxyethyl vinyl ether, and the like. One or more of these can be used. Examples of the carboxyl group-containing monomer in (2) include (meth) acrylic acid, crotonic acid, maleic acid, fumaric acid, itaconic acid, maleic anhydride, itaconic anhydride and the like. The above can be used.

As the silane compound in the above (2) and (4), those having two or more reactive silyl groups in one molecule are used. For example, tetrafunctional alkoxy such as tetraethoxysilane, tetramethoxysilane, tetrabutoxysilane and the like are used. Silanes: methyltrimethoxysilane, methyltriethoxysilane, methyltributoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, ethyltributoxysilane, propyltrimethoxysilane, propyltriethoxysilane, butyltrimethoxysilane, butyltrimethoxysilane Trifunctional alkoxysilanes such as ethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, and phenyltributoxysilane; dimethyldimethoxysilane, dimethyldiethoxysilane, dimethyldibutoxysilane, diethyl Dimethoxysilane, diethyldiethoxysilane, dipropyldimethoxysilane, dipropyldiethoxysilane, dibutyldimethoxysilane, dibutyldiethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, diphenyldibutoxysilane, methylphenyldimethoxysilane, methylphenyldi Bifunctional alkoxysilanes such as ethoxysilane; tetrachlorosilane, methyltrichlorosilane, ethyltrichlorosilane, propyltrichlorosilane, phenyltrichlorosilane, vinyltrichlorosilane, dimethyldichlorosilane, diethyldichlorosilane, diphenyldichlorosilane, methylphenyldichlorosilane, etc. Chlorosilanes; tetraacetoxysilane, methyltriacetoxysilane, phenyltriacetate Shishiran, dimethyldiacetoxysilane, acetoxy silanes such as diphenyl diacetoxy silane and the like, can be used one or two or more thereof. Further, a compound having one reactive silyl group in one molecule can be used in combination.

Examples of the combination of the functional groups in the above (3) and (4) include a hydroxyl group and an isocyanate group, an amino group and an isocyanate group, a carboxyl group and an epoxy group, an amino group and an epoxy group, and an alkoxysilyl group. The silane coupling agent is, for example, a compound having at least one or more reactive silyl groups and other substituents in one molecule. Specifically, β- (3,4 epoxycyclohexyl) ethyltrimethoxy Silane, γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropyltriethoxysilane, N- (β-aminoethyl) -γ-aminopropylmethyldimethoxysilane, N- (β-aminoethyl) -γ -Aminopropyltrimethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, isocyanate-functional silane and the like, and one or more of these can be used.

Other copolymerizable monomers copolymerizable with these monomers, for example,
Amino group-containing monomers such as dimethylaminoethyl (meth) acrylate and dimethylaminopropyl (meth) acrylate;
Amide group-containing monomers such as (meth) acrylamide and ethyl (meth) acrylamide; nitrile group-containing monomers such as acrylonitrile;
Epoxy group-containing monomers such as glycidyl (meth) acrylate;
Aromatic vinyl monomers such as styrene, methylstyrene, chlorostyrene and vinyltoluene;
Sulfonic acid-containing vinyl monomers such as styrene sulfonic acid and vinyl sulfonic acid;
Acid anhydrides such as maleic anhydride and itaconic anhydride; chlorine-containing monomers such as vinyl chloride, vinylidene chloride and chloroprene;
Alkylene glycol monoallyl ethers such as ethylene glycol monoallyl ether, propylene glycol monoallyl ether and diethylene glycol monoallyl ether;
Vinyl ester monomers such as vinyl acetate and vinyl propionate;
Ethylene, propylene, isobutylene and the like can be used. These can be used alone or in combination of two or more. In addition, an ultraviolet absorber containing an ethylenically unsaturated double bond, a light stabilizer containing an ethylenically unsaturated double bond, and the like can also be used.

Silicon component amount in the silicon-modified acrylic resin emulsion, 0.1 to 30 wt% in terms of SiO ₂ in the solid of the emulsion content (more preferably 0.2 to 10% by weight) is preferred. When the amount of the silicon component is in such a range, excellent performance can be exhibited in the adhesion to the above-described permeable water absorption preventing material, and the durability and the like of the inorganic material can be enhanced.

The term “SiO ₂ equivalent” means that a compound having a Si—O bond is completely hydrolyzed and then converted to silica (SiO ₂ ) when calcined at 900 ° C., and is expressed as a weight. In general, alkoxysilane, silicate, and the like have a property of reacting with water to cause a hydrolysis reaction to form silanol, and to cause a condensation reaction between silanols or silanol and alkoxy. When this reaction is performed to the ultimate, silica (SiO ₂ ) is obtained. These reactions have the general formula
RO (Si (OR) ₂ O) _n R + (n + 1) H ₂ O → nSiO ₂ + (2n + 2) ROH
It is represented by the following reaction formula. In the present invention, the amount of the silicon component is converted based on this reaction formula.

  It is preferable that the coating material in the second step forms a clear coating. Thereby, the texture of the inorganic material can be utilized. In addition, the coating material in the second step is, besides the above components, a colorant, a thickener, a wetting agent, an antifreezing agent, a film-forming aid, a preservative, and the like, as long as the effects of the present invention are not significantly impaired. It may contain an antifungal agent, an antialgal agent, an antibacterial agent, a dispersant, an antifoaming agent, a resin, an ultraviolet absorber, a light stabilizer, an antioxidant, a catalyst and the like. Further, as long as the effects of the present invention are not significantly impaired, synthetic resin emulsions other than those described above may be included as the synthetic resin emulsion. The coating material can be manufactured by uniformly mixing the above-described components by a conventional method.

In the second step, such a coating material is uniformly applied to the substrate. The application device is not particularly limited, and a known application device such as a brush, a spray, a roller, or a coater can be used. The required amount when coating the coating material may be appropriately set in consideration of the type and state of the base material, but is preferably about 30 to 500 g / m ² (more preferably about 80 to 200 g / m ² ). is there. The coating and drying of the coating material may preferably be performed at room temperature.

In the present invention, after the second step, a coating material similar to the second step or a coating material different from the second step is applied as a third step for the purpose of imparting decorativeness or enhancing surface protection. You can also.

As the coating material in the third step, a material that forms a clear coating is preferable. For example, a coating material containing a resin component such as an acrylic resin, a urethane resin, an acrylic silicon resin, a fluororesin, or a composite thereof is used. Is preferred. The form of the resin is not particularly limited, but a water-soluble resin and a water-dispersible resin are preferable.

  The coating material in the third step preferably contains a low-polluting agent in addition to the resin component. As the low-pollution agent, a silicate compound is preferable, and an alkylene oxide-modified silicate is more preferable. Examples of the alkylene oxide include methylene oxide, ethylene oxide, propylene oxide, butylene oxide and the like. Of these, ethylene oxide and / or propylene oxide are preferably used. By the action of such a specific modified silicate, the hydrophilicity of the surface of the coating film is increased, and excellent performance in stain resistance can be exhibited.

Further, the coating material of the third step may contain, in addition to the above components, a colorant, a thickener, a wetting agent, an antifreezing agent, a film-forming aid, a preservative, and the like, as long as the effects of the present invention are not significantly impaired. It may contain an antifungal agent, an antialgal agent, an antibacterial agent, a dispersant, an antifoaming agent, a resin, an ultraviolet absorber, a light stabilizer, an antioxidant, a catalyst and the like.

It is desirable that the coating material in the third step is uniformly applied to the substrate. The application device is not particularly limited, and a known application device such as a brush, a spray, a roller, or a coater can be used. The required amount when coating the coating material may be appropriately set in consideration of the type and state of the base material, but is preferably about 30 to 500 g / m ² (more preferably about 80 to 200 g / m ² ). is there. The coating and drying of the coating material may preferably be performed at room temperature.

Examples are shown below to further clarify the features of the present invention.
[Permeable water absorption prevention material]
-Permeable water absorption preventing material A (mixture of hexyltrimethoxysilane and aliphatic hydrocarbon solvent, weight ratio 3:97)
-Permeable water absorption preventing material B (mixture of hexyltrimethoxysilane and aliphatic hydrocarbon solvent, weight ratio 12:88)
-Permeable water absorption preventing material C (hexyltrimethoxysilane, soluble acrylic resin, mixture of aliphatic hydrocarbon solvents, weight ratio 3:25:72)

[Coating material]
・ Coating material A
Synthetic resin emulsion A [silicon-modified acrylic resin emulsion (cyclohexyl methacrylate, methyl methacrylate, 2-ethylhexyl acrylate, γ-methacryloyloxypropyltrimethoxysilane copolymer methyltrimethoxysilane adduct, cyclohexyl methacrylate content 20 in solid content) % By weight, 2% by weight of the silicon component in the solid content, 50% by weight of the solid content, Tg of 32 ° C., average particle diameter of 78 nm)] 100 parts by weight, 4 parts by weight of a film forming aid, 0.2 parts by weight of an ultraviolet absorber, A coating material A was obtained by uniformly mixing 0.1 parts by weight of an antifoaming agent and 10 parts by weight of water.

・ Coating material B
Synthetic resin emulsion B [silicon-modified acrylic resin emulsion (t-butyl methacrylate, cyclohexyl methacrylate, methyl methacrylate, 2-ethylhexyl acrylate, γ-methacryloyloxypropyltrimethoxysilane copolymer methyltrimethoxysilane adduct, solid content t-butyl methacrylate content: 10% by weight, cyclohexyl methacrylate content in the solid content: 10% by weight, silicon content in the solid content: 2% by weight, solid content: 50% by weight, Tg: 38 ° C, average particle diameter: 75 nm)] Parts, 4 parts by weight of a film forming aid, 0.2 parts by weight of an ultraviolet absorber, 0.1 parts by weight of an antifoaming agent, and 10 parts by weight of water were uniformly mixed to obtain a coating material B.

・ Coating material C
Synthetic resin emulsion C [silicon-modified acrylic resin emulsion (cyclohexyl methacrylate / methyl methacrylate / 2-ethylhexyl acrylate / γ-methacryloyloxypropyltrimethoxysilane copolymer methyltrimethoxysilane adduct, cyclohexyl methacrylate content 20 in solid content) % By weight, 2% by weight of the silicon component in the solid content, 50% by weight of the solid content, Tg of 50 ° C., average particle size of 72 nm)] 100 parts by weight, 5 parts by weight of a film forming aid, 0.2 parts by weight of an ultraviolet absorber, A coating material C was obtained by uniformly mixing 0.1 part by weight of an antifoaming agent and 10 parts by weight of water.

・ Coating material D
Synthetic resin emulsion D [silicon-modified acrylic resin emulsion (cyclohexyl methacrylate / methyl methacrylate / 2-ethylhexyl acrylate / γ-methacryloyloxypropyltrimethoxysilane copolymer methyltrimethoxysilane adduct, cyclohexyl methacrylate content 20 in solid content) % By weight, 8% by weight of the silicon component in the solid content, 50% by weight of the solid content, Tg of 36 ° C., average particle diameter of 75 nm)] 100 parts by weight, 4 parts by weight of a film-forming auxiliary, 0.2 parts by weight of an ultraviolet absorber, A coating material D was obtained by uniformly mixing 0.1 part by weight of an antifoaming agent and 10 parts by weight of water.

・ Coating material E
Synthetic resin emulsion E [silicon-modified acrylic resin emulsion (cyclohexyl methacrylate, methyl methacrylate, 2-ethylhexyl acrylate, γ-methacryloyloxypropyl trimethoxysilane copolymer methyltrimethoxysilane adduct, cyclohexyl methacrylate content 6 in solids) % By weight, 2% by weight of the silicon component in the solid content, 50% by weight of the solid content, Tg of 32 ° C., average particle diameter of 78 nm)] 100 parts by weight, 3 parts by weight of a film-forming auxiliary, 0.2 parts by weight of an ultraviolet absorber, A coating material E was obtained by uniformly mixing 0.1 part by weight of an antifoaming agent and 10 parts by weight of water.

・ Coating material F
Synthetic resin emulsion F [silicon-modified acrylic resin emulsion (cyclohexyl methacrylate / methyl methacrylate / 2-ethylhexyl acrylate / γ-methacryloyloxypropyltrimethoxysilane copolymer methyltrimethoxysilane adduct, cyclohexyl methacrylate content 20 in solid content) % By weight, 2% by weight of the silicon component in the solid content, 50% by weight of the solid content, Tg of 12 ° C., average particle size of 72 nm)] 100 parts by weight, 3 parts by weight of a film forming aid, 0.2 parts by weight of an ultraviolet absorber, A coating material F was obtained by uniformly mixing 0.1 part by weight of an antifoaming agent and 10 parts by weight of water.

・ Coating material G
Synthetic resin emulsion G [silicon-modified acrylic resin emulsion (cyclohexyl methacrylate / methyl methacrylate / 2-ethylhexyl acrylate / γ-methacryloyloxypropyltrimethoxysilane copolymer methyltrimethoxysilane adduct, cyclohexyl methacrylate content 20 in solid content) % By weight, 2% by weight of a silicon component in a solid content, 50% by weight of a solid content, Tg of 32 ° C., average particle size of 130 nm)] 100 parts by weight, 4 parts by weight of a film-forming auxiliary, 0.2 parts by weight of an ultraviolet absorber, A coating material G was obtained by uniformly mixing 0.1 part by weight of an antifoaming agent and 10 parts by weight of water.

・ Coating material H
Synthetic resin emulsion H [acrylic resin emulsion (cyclohexyl methacrylate / methyl methacrylate / 2-ethylhexyl acrylate copolymer; cyclohexyl methacrylate content in solids: 20% by weight; solids: 50% by weight; Tg: 32 ° C; average particle diameter: 80 nm)] 100 parts by weight, 4 parts by weight of a film-forming aid, 0.2 parts by weight of an ultraviolet absorber, 0.1 parts by weight of an antifoaming agent, and 10 parts by weight of water were uniformly mixed to obtain a coating material H.

・ Coating material I
100 parts by weight of a synthetic resin emulsion I [acrylic resin emulsion (methyl methacrylate / 2-ethylhexyl acrylate copolymer, solid content 50% by weight, Tg 32 ° C., average particle diameter 80 nm)], 4 parts by weight of a film-forming aid, and an ultraviolet absorber 0.2 parts by weight, 0.1 parts by weight of an antifoaming agent, and 10 parts by weight of water were uniformly mixed to obtain a coating material I.

(Examples 1 to 10, Comparative Example 1)
As a first step, a test substrate made of cement mortar is coated with a permeable water-absorbing preventive material at a required amount of 200 g / m ² with a brush on the entire surface, and dried under standard conditions (temperature 23 ° C., relative humidity 50%) for 16 hours. I let it. Next, as a second step, a coating material was brush-coated on the entire surface at a required amount of 100 g / m ² , dried for 24 hours in a standard state, cured for 14 days, and dried for 14 days to prepare a test body. went. The coating formed on each specimen had a finish utilizing the texture of the substrate. Table 1 shows the combinations of the permeable water absorption preventing material and the coating material, and the results.

-Water absorption prevention test The test piece was fixed vertically, and water was continuously sprayed on the test piece using a hose for 60 minutes, and the color change at that time was observed. The evaluation criteria were as follows: “◎” for no color change before and after the test, “「 ”for little color change,“ △ ”for color change, marked color change Those that were recognized were rated "x".

  The test piece after the water absorption prevention test was evaluated for adhesion by a cross-cut method according to JIS K 5600-5-6. The evaluation criteria are “◎” when the area of the defective portion is 5% or less, “」 ”when the area of the defective area is more than 5% and 20% or less, and“ △ ”when the area of the defective area is more than 20% and 35% or less. ”, And those having a defect area of more than 35% were rated“ x ”.

-Durability test The test specimens were subjected to a total of 10 cycles of heating and cooling with one cycle of immersion in water (20 ° C) for 18 hours → -20 ° C for 3 hours → 50 ° C for 3 hours. Thereafter, the adhesion was evaluated by a cross-cut method according to JIS K 5600-5-6. The evaluation criteria are “◎” when the area of the defective portion is 5% or less, “」 ”when the area of the defective area is more than 5% and 20% or less, and“ △ ”when the area of the defective area is more than 20% and 35% or less. ”, And those having a defect area of more than 35% were rated“ x ”.

(Example 11)
In the same manner as in Example 1, after applying and drying the permeable water-absorbing material A as the first step and the coating material A as the second step, the required amount of the fluororesin emulsion-containing clear coating material as the third step is obtained. The entire surface was brush-coated at 100 g / m ² , dried under a standard condition for 24 hours, cured for a side surface, and further dried for 14 days to prepare a test body. The same evaluation as in Example 1 was performed. As a result, an evaluation of “◎” was obtained in all the tests. Further, the obtained test specimen had a finish utilizing the texture of the substrate.

Claims (5)

A method for forming a film on an inorganic material,
For the surface of the inorganic material,
After applying the permeable water absorption prevention material as the first step,
As a second step, a coating material containing a synthetic resin emulsion (excluding those having a pigment volume concentration of 30% or more) is applied,
The synthetic resin emulsion, as a monomer constituting the synthetic resin,
The glass transition temperature of the homopolymer 50 ° C. or higher, the solubility parameter is 9.5 or less (meth) acrylic acid alkyl esters seen including,
The method for forming a film, wherein the alkyl (meth) acrylate contains cyclohexyl methacrylate .   The method according to claim 1, wherein the synthetic resin emulsion has a glass transition temperature of 10 to 60C.   3. The method according to claim 1, wherein the synthetic resin emulsion has an average particle diameter of 120 nm or less.   The method according to any one of claims 1 to 3, wherein the synthetic resin emulsion is a silicone-modified acrylic resin emulsion. The method according to any one of claims 1 to 4, wherein the content of the alkyl (meth) acrylate in the solid content of the synthetic resin emulsion is 3 to 70% by weight.