JP4580170B2 - Mirror surface finishing method of inorganic porous material, and painted product - Google Patents

Description

  The present invention relates to a method for mirror finishing of an inorganic porous material, which is capable of mirror finishing (smooth finishing) on the surface of an inorganic porous substrate such as concrete and having excellent back surface water blocking performance. The method of the present invention is particularly useful in the field of civil engineering and architecture.

  In recent years, the outer walls of high-rise buildings such as airports and stations are often constructed by the curtain wall method, the stone-clad method, the tiled method, etc., and recently, it is called “mirror finish” for large concrete plates such as precast concrete plates. A method has been adopted in which a coated plate that has been finished up to a finish with excellent smoothness is manufactured in a factory, and this is carried into a construction site and built.

  To apply a mirror finish as described above to a substrate with a porous surface such as a concrete board, coat with a primer and filler to ensure durability and waterproofness, and a putty for filling holes. In general, intermediate coating or top coating is applied. However, as the size of precast concrete plates increases, the concrete plates are often placed outdoors during or after construction, and when exposed to rain, water penetrates from the pores present on the surface, You will be forced to paint with increased moisture content. Therefore, there has been a problem that defects such as blisters, cracks, and cracks occur in the coating film covering the surface of the concrete board due to evaporation of moisture present in the concrete board.

  Therefore, in Patent Document 1 or the like, a concrete plate having a large number of pores on its surface is preheated for a short time prior to coating, and the water content of the concrete plate is adjusted by this preheating, and then a water-based paint is applied. A method has been proposed.

JP 2002-66449 A

  However, when a concrete board is placed outdoors during or after a number of painting processes, moisture entering from the non-painted part and moisture from the concrete board itself (referred to as "backside water" or "water pushing") There is a problem that the coating film of the painted part is pushed up by the vapor due to the above) and causes problems such as blistering, peeling and cracking.

  An object of the present invention is to provide a coating method in which a coating film formed on the surface of an inorganic porous substrate such as concrete is excellent in water-blocking performance on the back surface, and the substrate can be mirror-finished (smooth finish). It is to provide.

As a result of intensive studies to solve the above problems, the present inventors sequentially applied a water permeation preventive agent, an organic solvent type epoxy primer, and an organic solvent type urethane curing filler to the surface of the inorganic porous substrate, Furthermore, it has been found that by applying a top coating (D) thereon, a coated product having excellent finish and back surface water blocking performance can be obtained, and the present invention has been completed.

That is, in the present invention, a water permeation preventive agent (A) containing a silane compound (a) having a hydrolyzable functional group is coated on the surface of an inorganic porous substrate, dried, and then an organic solvent-type epoxy system thereon. The primer (B) is coated, and then an organic solvent type resin containing a hydroxyl group-containing resin (b), a pigment (c), a resin fine particle (d), a polyisocyanate compound (e), and a curing catalyst (f) . The present invention relates to a method for mirror finishing of an inorganic porous material, characterized in that a urethane curable filler (C) is coated and a top coating (D) is further coated thereon, and a coated product obtained by the method.

  According to the method of the present invention, an inorganic porous substrate, particularly a concrete material surface, can be particularly finished with a mirror finish (smooth finish), and can further form a coated product with excellent back surface water blocking performance. Is possible. The method of the present invention can be applied in various fields for the purpose of protecting the inorganic porous substrate and imparting design properties, and is particularly useful in the fields of civil engineering and architecture.

  The coating method of the present invention can be applied to an inorganic porous substrate or a building composed thereof, and examples of the inorganic porous substrate include concrete, slate, mortar, calcium silicate-based material, gypsum, and slag-based material. And other cement-based substrates such as stones. In particular, the coating method of the present invention is preferably applied to concrete materials such as precast concrete boards (PC boards), extruded concrete boards, lightweight cellular concrete boards (ALC boards).

  In the method of the present invention, a silane compound, which is a component in a water permeation preventive agent (A) described later, permeates into an inorganic porous substrate such as a concrete material and the surface reinforcing action of the substrate, the coating film on the substrate It also improves the adhesion and water backwater blocking performance.

  In the case of using a concrete material as a base material, it is desirable to dry the concrete surface so that the moisture on the concrete surface is 10% or less and then apply a water permeation preventive agent (A) described later.

  The water permeation preventive agent (A) used in the method of the present invention is applied for the purpose of lowering the water permeability from the base material to the upper coating film, and has a hydrolyzable functional group (a). Is contained as an essential component.

  The silane compound (a) having a hydrolyzable functional group is a monomer, dimer, trimer or oligomer of a compound represented by the following formula.

R ¹ _n —Si— (R ² ) _4-n
In the formula, n is an integer of 1, 2 or 3, preferably 1. R ¹ is a stable hydrophobic group, for example, a hydrocarbon-based substituent such as an alkyl group or a phenyl group, and among them, a saturated alkyl group is preferable in terms of hydrophobicity. R ² is a hydrolyzable group, and examples thereof include an alkoxy group such as a methoxy group and an ethoxy group, a hydroxyl group, a halogen atom, an acetoxy group, a carboxyl group, and an isocyanate group. From the viewpoint of storage stability and ease of handling. An alkoxy group is particularly preferable. In addition, when there are a plurality of R ¹ and R ² , they may be the same or different.

  Specific examples of the silane compound (a) include methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, dimethyldimethoxysilane, dimethylditriethoxysilane, ethyltri-n-propoxysilane, and butyl. Trimethoxysilane, butyltriethoxysilane, butyldimethoxysilane, isobutyltrimethoxysilane, isobutyltriethoxysilane, isobutyltrimethoxysilane, hexyltrimethoxysilane, hexyltriethoxysilane, cyclohexyltrimethoxysilane, benzyltrimethoxysilane, phenyltri Methoxysilane, octyltrimethoxysilane, octyltriisopropoxysilane, 2-ethylhexyltrimethoxysilane, decyltrimethyl Examples include silane, dodecyltrimethoxysilane, tetradecyltriethoxysilane, etc., or dimers, trimers and other oligomers alone, and mixtures thereof. These are used alone or in combination of two or more. Can also be used together. Of these, alkylalkoxysilanes are preferable, and alkyltrimethoxysilane is particularly preferable.

  A catalyst capable of accelerating the condensation reaction of a silanol group generated by hydrolysis of the alkoxysilyl group can be added to the water permeation preventive agent (A) as necessary. Examples of such catalysts include organic titanate compounds such as isopropyl triisostearoyl titanate and isopropyl tri (dioctyl pyrophosphate) titanate, organotin compounds such as dioctyltin, dibutyltin dilaurate and dibutyltin malate, and paratoluenesulfonic acid. Organic acids are mentioned.

  The water permeation preventive agent (A) is mixed with additives such as an emulsifier and a pH (hydrogen ion concentration) adjuster as necessary in the silane compound (a), so that the solid content concentration is about 10 to 40% by weight. Thus, it may be dissolved, dispersed, emulsified in an aqueous medium to make it aqueous, or the silane compound (a) is dissolved and diluted with an organic solvent so that the solid content concentration is about 10 to 40% by weight. A solvent-type composition may be used. From the viewpoint of the painting work environment, an aqueous composition is desirable.

As a method for coating the base material with the water permeation preventive agent (A), a conventionally known method can be employed without particular limitation, and specific examples include spray coating, roller coating, brush coating and the like. The coating amount of the water permeation preventive agent (A) can be appropriately set according to the inorganic porous substrate to be applied and the purpose, and is preferably in the range of 50 to 400 g / m ² , particularly 100 to 300 g / m ² (in terms of solid content). Is suitable and is applied once or several times.

  After the coating surface with the water permeation preventive agent (A) is dried, the epoxy primer (B) is coated thereon.

  The epoxy primer (B) used in the method of the present invention is applied for the purpose of improving the adhesion to the substrate surface, and usually contains an epoxy resin and an amine curing agent as main components. is there.

  The epoxy resin is a resin that is liquid or solid at room temperature and has 2 or more, preferably 2 to 5 average epoxy groups in one molecule. Specifically, the resin that is liquid at room temperature is a resin having a viscosity at 25 ° C. of 15000 mPa · s or less, preferably 5000 mPa · s or less.

  Examples of the epoxy resin include glycidyl ether type epoxy resins, glycidyl ester type epoxy resins, other glycidyl ether type epoxy resins, alicyclic epoxy resins, and modified products obtained by modifying these epoxy resins with alkylphenols and / or fatty acids. An epoxy group-introduced alkylphenol or alkylphenol novolac type resin obtained by reacting an epoxy resin or an alkyldiphenol or an alkylphenol novolak type resin with epichlorohydrin can be used.

  As the epoxy resin, an epoxy group-introduced alkylphenol or alkylphenol novolac resin obtained by reacting an alkyldiphenol or alkylphenol novolac resin with epichlorohydrin as a liquid resin, or a bisphenol A epoxy resin is particularly suitable. As the resin, a bisphenol A type epoxy resin and a modified epoxy resin obtained by modifying this with an alkylphenol or / and a fatty acid are preferable from the viewpoint of the film forming property and toughness of the resulting coating film. Also, an acrylic-modified epoxy resin obtained by reacting a dibasic acid and a carboxyl group-containing acrylic resin with these epoxy resins, or a polybasic addition of dibasic acid and graft polymerization or copolymerization of a polymerizable unsaturated monomer to the epoxy resin. Acrylic-modified epoxy resins, and further modified epoxy resins that also use carboxyl group-containing phenols for the modification of these acrylic-modified epoxy resins can be suitably used when solubility in weak solvents such as mineral spirits and drying properties are required. .

  If necessary, the epoxy resin may be selected from urethane-modified epoxy resin, dimer acid-modified epoxy resin, xylene resin, toluene resin, ketone resin, coumarone resin, petroleum resin, etc. From the viewpoint of improving the drying property and the like, they can be used together as appropriate.

  The amine-based curing agent is a curing agent for the epoxy resin, and any conventionally known one can be used without particular limitation, and is preferably liquid at room temperature. The amine curing agent is generally a polyamine compound having a primary amino group equivalent in the range of about 2000 or less, preferably in the range of about 30 to about 1000, which is also generally about 5000 or less, preferably Preferably has a number average molecular weight in the range of about 60-3000.

  Examples of the polyamine compound include aliphatic polyamines such as ethylenediamine, propylenediamine, butylenediamine, hexamethylenediamine, diethylenetriamine, triethylenetetramine, and pentaethylenehexamine; aromatic polyamines such as metaxylylenediamine, diaminodiphenylmethane, and phenylenediamine. And alicyclic polyamines such as 1,3-bis (aminomethyl) cyclohexane and isophoronediamine.

  Further, examples of the amine curing agent include ketimine compounds in which the amino group of the polyamine compound is blocked with a dialkyl ketone. By using the ketimine compound, the epoxy primer (B) can be made into a one-component composition.

  The mixing ratio of the amine curing agent is such that the active hydrogen in the amine curing agent is 0.5 to 3.0 equivalents, preferably 0.8 to 1.5 equivalents, relative to 1 equivalent of the epoxy group in the epoxy resin. It is desirable from the viewpoint of curability, non-adhesiveness, and corrosion resistance of the coating film.

  The epoxy primer (B) can be blended with pigments such as color pigments, extender pigments and rust preventive pigments as required, and the pigment volume concentration of the entire pigment in the paint is preferably 20 to 70%, preferably Is preferably in the range of 30 to 60%.

  The epoxy primer (B) further includes an organic solvent, a reactive diluent, a dehydrating agent, a modifying resin component, a non-aqueous dispersion resin, a thickener, a resin fine particle, a plasticizer, a dispersant, if necessary. An additive such as a dehydrating agent can be contained.

As a coating method of the epoxy primer (B), general methods such as brush coating, roller coating, spray coating, and various coater coatings can be used. The coating amount is not particularly limited, but is usually in the range of 100 to 400 g / m ² , and is applied once or several times.

  In the method of the present invention, after applying the water permeation preventive agent (A), before applying the epoxy primer (B), a polymer cement paint (E) can be applied as necessary.

  The polymer cement-based paint (E) is applied for the purpose of following the fine cracks generated on the surface of the base material depending on the type of the base material. Usually, cement, a mixed resin component, water, etc. are used. It is a main component and contains a pigment, an aggregate, a silane coupling agent, a fibrous substance, a water reducing agent, a surfactant, an antifoaming agent, a thickening agent and the like as necessary.

  Examples of the cement include Portland cement, blast furnace cement, silica cement, fly ash cement, alumina cement, acidic phosphate cement, and Keens cement.

  The above-mentioned admixture resin component is for improving the adhesiveness of cement mortar obtained by mixing with cement, and emulsion type and self-emulsification type resins can be used, for example, acrylic resin, epoxy resin, vinyl acetate resin, ethylene -A vinyl acetate copolymer, a styrene-butadiene copolymer, etc. are mentioned, These can be used individually or in combination. Of these, emulsion type or self-emulsifying type acrylic resin or epoxy resin can be suitably used. When using an epoxy resin, an amine compound can be used in combination as a curing agent.

The polymer cement-based paint (E) can be usually applied by brush coating, roller coating, spray coating, or the like. The coating amount is not particularly limited, but is usually in the range of about 400 to 1,000 g / m ² .

  In the method of the present invention, after drying the coating film with the epoxy primer (B) or the coating film with the polymer cement coating material (E), polishing is performed as necessary, and then a urethane curable filler ( C) is painted.

  The urethane curable filler (C) used in the method of the present invention is applied in order to conceal the ground polishing scratches and make a smooth coating surface, and includes a hydroxyl group-containing resin (b) and a pigment (c). , Resin fine particles (d), polyisocyanate compound (e), and curing catalyst (f).

  Examples of the hydroxyl group-containing resin (b) include mainly hydroxyl group-containing acrylic resins. Particularly, the hydroxyl value is 30 to 85, preferably 40 to 70, and the weight average molecular weight is 1,000 to 50,000, preferably 3. Acrylic resins having a viscosity of 20,000 to 20,000 are preferable from the viewpoint of coating film performance and the like. The acrylic resin preferably has a glass transition temperature (Tg) in the range of 20 to 70 ° C. from the viewpoint of polishing workability.

  As the monomer constituting the acrylic resin, an acrylic monomer having a hydroxyl group is essential, and other acrylic monomers and / or vinyl monomers are used, and these monomers are polymerized by ordinary radical polymerization or the like. Can be obtained. Examples of the monomer having a hydroxyl group include (meth) acrylic acid hydroxyalkyl esters such as 2-hydroxyethyl methacrylate, 2-hydroxyethyl acrylate, hydroxypropyl methacrylate, hydroxypropyl acrylate, 4-hydroxybutyl acrylate, and (meth) acrylic. Examples include lactone-modified α, β-ethylenically unsaturated monomers obtained by adding 1 to 10 moles of lactones such as ε-caprolactone and γ-butyrolactone to the acid hydroxyalkyl ester. Examples of other acrylic monomers and / or vinyl monomers include methyl (meth) acrylate, n-butyl (meth) acrylate, iso-butyl (meth) acrylate, tert-butyl (meth) acrylate, and 2-ethylhexyl. (Meth) acrylate, cyclohexyl (meth) acrylate, lauryl (meth) acrylate, styrene, α-methylstyrene, (meth) acrylic acid and the like can be mentioned. Examples of normal radical polymerization include solution polymerization.

  As the pigment (c), for example, extender pigments such as talc, mica, barium sulfate, kaolin, calcium carbonate, clay, silica, quartz, and glass can be used, and titanium white, bengara, carbon black, iron black, and the like. May also be included. The content of the pigment (c) is 100 to 500 parts by weight, preferably 150 to 350 parts by weight with respect to 100 parts by weight of the resin solid content in the paint, from the viewpoint of polishing workability and finish after finish coating. Is preferred. It is desirable to use a pigment dispersant for dispersing the pigment (c).

  Examples of the resin fine particles (d) include conventionally known resin particles such as polymer beads, finely pulverized polymers of the above monomers, and gelled polymer fine particles (for example, JP-A-51-126287). No. 53, No. 53-133233, No. 53-133236, No. 56-76447, No. 58-129065, etc., particularly including divinyl monomers. Gelled polymer fine particles obtained by emulsion polymerization of a monomer mixture in the presence of an allyl group-containing reactive emulsifier (for example, see JP-A-3-66770) are dispersed in the components (b) and (c). Since it is excellent in properties, it can be suitably used.

  Examples of the divinyl monomer used in the production of the gelled polymer fine particles include ethylene glycol di (meth) acrylate and 1,6-hexanediol diacrylate, and other monomers include, for example, Conventionally known polymerizable unsaturated monomers such as (meth) acrylic acid alkyl ester, hydroxyl group-containing monomer, styrene and the like can be mentioned and appropriately selected. Moreover, a water-soluble azoamide compound etc. can be used as a polymerization initiator at the time of emulsion polymerization.

  The particle size of the resin fine particles (d) can be appropriately selected without particular limitation, but is usually 30 μm or less, preferably 0.05 to 10 μm. The particle diameter can be adjusted by a conventionally known method. For example, the gelled polymer fine particles can be adjusted by adjusting the type and amount of the reactive emulsifier.

  The resin fine particles (d) are blended so that the solid content is 0.1 to 5% by weight, preferably 0.5 to 2% by weight, based on the weight of the component (c). It is preferable from the viewpoint of storage stability.

  The polyisocyanate compound (e) is a polyisocyanate compound having 2 or more, preferably 3 isocyanate groups in one molecule. Specific examples thereof include hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, isophorone diisocyanate, hydrogenated xylylene diisocyanate, xylylene diisocyanate, meta-tetramethylxylylene diisocyanate, tolylene diisocyanate, 4,4 ′. -Polyisocyanate compounds such as diphenylmethane diisocyanate and lysine diisocyanate, or adducts of these polyisocyanates with polyhydric alcohols, low molecular weight polyester resins or water, or cyclized polymers of each polyisocyanate as described above Furthermore, an isocyanate biuret body etc. are mentioned, These may be used 1 type and may be used in combination of 2 or more type.

  In the urethane curable filler (C), the component (b) and the component (e) are mixed in an amount of 2.0 to 4 isocyanate groups in the component (e) with respect to 1 equivalent of the hydroxyl group in the component (b). It is suitable from the viewpoint of curability and dryness of the coating that it is blended so as to have a ratio of 0.0 equivalent, preferably 2.2 to 3.5 equivalent.

  As the curing catalyst (f), a conventionally known urethanization catalyst can be applied without particular limitation. For example, bismuth nitrate, lead oleate, tin octylate, dibutyltin dilaurate, dibutyltin bis (acetylacetonate), titanium tetrachloride, Examples thereof include metal compounds such as dibutyl titanium dichloride, tetrabutyl titanate, iron trichloride, and zinc octylate, and tertiary amines. The content of the curing catalyst (f) is 0.1 to 10% by weight, preferably 0.2 to 5% by weight, based on the resin solid content, from the viewpoint of curability and coating viscosity.

  If necessary, the urethane curable filler (C) may further contain coating additives such as organic solvents, fiber derivatives, non-aqueous dispersion resins, and leveling agents such as dimethylpolysiloxane copolymers. it can.

  The urethane-curing filler (C) thus obtained is usually a two-component paint, and generally contains a main component (e) and a component (b), (c), (d) and (f) immediately before coating. Is used for mixing with a curing agent containing.

As a method for coating the urethane curable filler (C), a conventionally known method can be employed without any particular limitation, and specific examples include spray coating, roller coating, brush coating, and the like. The coating amount of the urethane curable filler (C) can be appropriately set according to the inorganic porous substrate to be applied and the purpose, and is preferably 100 to 600 g / m ² , particularly 200 to 400 g / m ² . Painted once or several times.

  In the method of the present invention, after drying the coating film with the urethane curable filler (C), polishing is performed as necessary, and then the top coat paint (D) is applied on the urethane curable filler coating film. .

  The top coating (D) is not particularly limited, and a conventionally known organic solvent type or aqueous top coating can be applied, and examples thereof include fluorine resin, acrylic resin, urethane resin, and silicone resin, and particularly high durability. From the viewpoints of properties, finish, and stain resistance, a fluororesin-based top coating is preferred.

  In the top coat (D), an ultraviolet absorber, an antioxidant, a surface conditioner, a low pollution agent, an algaeproof agent, an antifungal agent and the like can be appropriately blended as necessary.

  The top coating (D) can be applied by any conventionally known method without particular limitation. Specifically, the top coating (D) can be applied by general methods such as brush coating, spray coating, roller coating, iron coating, and various coater coating methods. The coating amount is not particularly limited, and can be appropriately selected depending on the paint to be used, and can be applied once or several times.

  When the coating interval with the urethane-curing filler (C) is increased, the intermediate coating paint such as epoxy-based or urethane-based coating with urethane-curing filler ( After coating on the coating film according to C), an overcoating material may be applied thereon. As a coating method of the intermediate coating, general methods such as brush coating, roller coating, spray coating, and various coater coatings can be used, and the coating amount is not particularly limited, but usually a dry film The thickness is about 10 to 500 μm, preferably about 15 to 400 μm.

  Hereinafter, the present invention will be described in more detail with reference to examples. “Part” and “%” indicate “part by weight” and “% by weight” unless otherwise specified.

Adjustment of water permeation preventive agent (A) “Aqua Prism Undercoat” (trade name, solid content 20 wt%, coating viscosity 3 cp / 25 ° C., xylene solution of alkyltrialkoxysilane compound) manufactured by Kansai Paint Co., Ltd. A-1) and as a water permeation preventive agent (A-2), an aqueous dispersion having a solid content of 30% obtained by dissolving 30 parts of hexyltrimethoxysilane, 0.2 part of an emulsifier and 0.05 part of an organic tin catalyst in water. Was used.

Production of acrylic resin A reactor equipped with a thermometer, thermostat, stirrer, reflux condenser, and dropping pump was charged with 42 parts of xylene and 10 parts of butyl acetate. The temperature was raised to 110 ° C while stirring, and 10 parts of styrene Monomer and polymerization consisting of 10 parts of methyl methacrylate, 5 parts of n-butyl methacrylate, 60 parts of i-butyl methacrylate, 1 part of methacrylic acid, 14 parts of 2-hydroxyethyl methacrylate and 2.3 parts of azobisisobutyronitrile The mixture of initiators was added dropwise at a constant rate over 3 hours using a dropping pump at 110 ° C. or lower. After completion of dropping, the temperature was kept at 110 ° C. for 60 minutes and stirring was continued. Thereafter, a solution prepared by dissolving 0.5 part of azobisisobutyronitrile in 7 parts of butyl acetate as an additional catalyst was dropped at a constant rate over 60 minutes. And after completion | finish of dripping, it hold | maintained at 110 degreeC for 60 minutes, and reaction was complete | finished. The obtained hydroxyl group-containing acrylic resin solution was a uniform transparent solution having a nonvolatile content of 55% and a Gardener viscosity of X. The weight average molecular weight of the acrylic resin was 18000, the hydroxyl value was 60, and Tg was 60 ° C.

Production of resin fine particles In a 1 liter flask equipped with a stirrer, a thermometer, a cooling tube and a heating mantle, 3547.5 parts of deionized water and “Latemul S-120A” (manufactured by Kao Corporation, sulfosuccinic acid-based allyl group-containing anionic property) (Reactive emulsifier, 50% aqueous solution) 40 parts was added and the temperature was raised to 90 ° C. with stirring. Next, 20% of an aqueous solution obtained by dissolving 12.5 parts of “VA-086” (manufactured by Wako Pure Chemical Industries, Ltd., water-soluble azoamide polymerization initiator) in 500 parts of deionized water was added thereto. After 15 minutes, 5% of a monomer mixture comprising 300 parts of styrene, 400 parts of methyl methacrylate, 200 parts of n-butyl acrylate and 100 parts of 1,6-hexanediol diacrylate was added and stirred for 30 minutes. Thereafter, the dropping of the remaining monomer mixture and the polymerization initiator aqueous solution was started, the monomer mixture was dropped for 3 hours, and the polymerization initiator aqueous solution was dropped for 3.5 hours, and maintained at 90 ° C. during that time. did. After completion of the dropwise addition of the polymerization initiator aqueous solution, the mixture was kept at 90 ° C. for 30 minutes, cooled to room temperature, and taken out using a filter cloth to obtain an aqueous gelled fine particle polymer aqueous dispersion having a solid content of 20%. Its particle size was 72 nm. This was dried on a stainless steel pad to obtain resin fine particles G.

Preparation of Urethane Curing Filler (C) Into 25 parts of the acrylic resin solution having a solid content of 55% produced as described above, 0.3 part of the resin fine particles G, 22 parts of xylene, and tertiary amino group-containing pigment dispersant 2 6 parts, 10 parts of titanium white, 15 parts of talc, 10 parts of barium sulfate, 15 parts of calcium carbonate and 0.1 part of dibutyltin dilaurate were sequentially mixed, stirred and dispersed for 30 minutes to obtain a main agent. 40 parts of “Duranate TPA90EK” (manufactured by Asahi Kasei Co., Ltd.) as a curing agent was mixed with 100 parts of the main agent immediately before use to obtain a urethane curable filler (C).

Application Example 1
Air spray coating of a water permeation preventive agent (A-1) on a precast concrete (with river gravel) plate of 300 x 300 x 50 mm so that the applied amount is about 0.16 kg / m ² (solid content conversion). And dried at room temperature (20 ° C.) for 16 hours. On the obtained coating film, a polymer cement-based paint “Ares Filler” (trade name, manufactured by Kansai Paint Co., Ltd.) is appropriately diluted with clean water and airless spray-coated so that the coating amount is about 0.7 kg / m ^2. After drying for 24 hours at room temperature (20 ° C.), polishing was performed using # 80 sandpaper, and the obtained coating surface was made flat. On the flat coating film, an epoxy-based primer “multi-concrete primer EPO” (trade name, 2-pack type, manufactured by Kansai Paint Co., Ltd.) is appropriately diluted with a thinner so that the coating amount is about 0.18 kg / m ^2. After spray coating and drying at room temperature (20 ° C.) for 16 hours, after polishing with # 120 sandpaper, the urethane coating filler (C) is appropriately diluted with thinner on the obtained coating film. Apply air spray so that the coating amount is about 0.2 kg / m ² , dry at room temperature (20 ° C.) for 1 hour, and then use the urethane-cured filler (C) for the second time to achieve the same coating amount. It was painted, dried at room temperature (20 ° C.) for 1 hour, and polished with # 400 sandpaper to give a smooth coating surface.

On the smooth coating film thus obtained, a top coating “Serafuso top coating” (trade name, two-component ceramic-modified fluororesin-based coating manufactured by Kansai Paint Co., Ltd.) is appropriately diluted with a thinner and applied in an amount of about 0.18 kg / m ^2. After spraying at room temperature (20 ° C) for 24 hours, apply the same coating amount for the second time using the same top coat and dry at room temperature (20 ° C) for 7 days. A test coated plate was made.

Example 2
In Example 1, a test coated plate was prepared in the same manner as in Example 1 except that the water permeation preventive agent (A-2) was used instead of the water permeation preventive agent (A-1).

Comparative Example 1
In Example 1, the test coating board was created like Example 1 except the coating process by a water-permeation preventive agent (A-1) being remove | excluded.

Comparative Example 2
In Example 1, the test coating board was created like Example 1 except the coating process by a urethane hardening type filler (C) being remove | excluded.

Example 3
On an extruded concrete plate having a size of 300 × 300 × 50 mm, the water permeation preventive agent (A-1) was applied by air spray so that the coating amount was about 0.16 kg / m ² (in terms of solid content), and room temperature ( (20 ° C.) for 16 hours. On the obtained coating film, an epoxy-based primer “multi-concrete primer EPO” (trade name, 2-pack type, manufactured by Kansai Paint Co., Ltd.) is appropriately diluted with thinner so that the coating amount is about 0.18 kg / m ^2. After air spray coating and drying at room temperature (20 ° C.) for 16 hours and polishing with # 120 sandpaper, the urethane coating filler (C) is appropriately diluted with thinner on the obtained coating film. Air spray coating is performed so that the coating amount becomes about 0.2 kg / m ^2, and after drying for 1 hour at room temperature (20 ° C.), the second time so that the same coating amount is obtained using the urethane-cured filler (C). And dried at room temperature (20 ° C.) for 1 hour and polished with # 400 sandpaper to obtain a smooth coating surface.

On the obtained smooth coating film, a top coating “Serafuso top coating” (trade name, two-component ceramic-modified fluororesin-based coating manufactured by Kansai Paint Co., Ltd.) is appropriately diluted with a thinner and applied in an amount of about 0.18 kg / m ^2. After spraying at room temperature (20 ° C) for 24 hours, apply the same coating amount for the second time using the same top coat and dry at room temperature (20 ° C) for 7 days. A test coated plate was made.

Example 4
In Example 3, a test coated plate was prepared in the same manner as in Example 3 except that the water permeation preventive agent (A-2) was used instead of the water permeation preventive agent (A-1).

Comparative Example 3
In Example 3, a test coated plate was prepared in the same manner as in Example 3 except that the coating step with the water permeation preventive agent (A-1) was omitted.

Comparative Example 4
In Example 3, a test coated plate was prepared in the same manner as in Example 3 except that the coating step with the urethane curable filler (C) was omitted.

Test method (* 1) Finishability: The coating surface of each test coated plate was observed and evaluated according to the following criteria. The results are shown in Table 1.

A: Specular surface has good smoothness. Δ: Slightly poor skin. X: Quite inferior in smoothness.
(* 2) Warm / cool cycle test: Each test coated plate was subjected to the test method of JIS A-6909 “Resistance due to repeated heating / cooling” (after finishing the painted plate in 23 ± 2 ° C. water for 18 hours, Immediately cool in a -20 ± 2 ° C. constant temperature bath for 3 hours, then heat in a 50 ± 2 ° C. constant temperature bath for 3 hours). . The results are shown in Table 1.

○: No peeling or swelling, no significant discoloration and no gloss reduction ×: Even one of the above defects is observed

Claims (8)

A water permeation preventive agent (A) containing a silane compound (a) having a hydrolyzable functional group is applied to the surface of the inorganic porous substrate, dried, and then an organic solvent type epoxy primer (B) is applied thereon. An organic solvent-type urethane-curing filler (coating, and then containing a hydroxyl group-containing resin (b), a pigment (c), resin fine particles (d), a polyisocyanate compound (e), and a curing catalyst (f) A method for mirror finishing of an inorganic porous material, characterized in that C) is applied and further a top coat (D) is applied thereon. The mirror finishing method according to claim 1, wherein the polymer cement-based paint (E) is applied after the water permeation preventive agent (A) is applied and before the epoxy primer (B) is applied. The mirror surface finishing method according to claim 1 or 2, wherein the epoxy primer (B) contains an epoxy resin and an amine curing agent. In the urethane cured filler (C), the isocyanate group in the polyisocyanate compound (e) is 2.0 to 4.0 equivalents relative to 1 equivalent of the hydroxyl group in the hydroxyl group-containing resin (b). The mirror surface finishing method according to claim 1 or 2, which is contained in a proportion. In the urethane cured filler (C), the content of the pigment (c) is 100 to 500 parts by weight with respect to 100 parts by weight of the resin solid content in the paint, and the resin fine particles (d) are based on the weight of the pigment (c). The mirror surface finishing method according to claim 1 or 2, wherein the solid surface content is 0.1 to 5% by weight. The mirror finish method according to claim 1 or 2, wherein the top coating (D) is a fluororesin coating. The mirror finishing method according to claim 1 or 2, wherein the inorganic porous substrate is a concrete material. A coated product obtained by the mirror finishing method according to any one of claims 1 to 7.