Painting method and coating laminate

Abstract

To provide a coating method which suppresses generation of rust and enables formation of coating film capable of retaining an aesthetic appearance for a long period, with respect to concrete base metal containing metallic fibers, and to provide a coating film laminate obtained according to the coating method.SOLUTION: In a coating method for concrete base metal, the concrete base metal contains metallic fibers, and after coating an undercoat material to form an undercoat material layer, a finishing material is coated to form a finishing material layer, on the concrete base metal. In the coating method, an average dry film thickness of a coated coating film layer including the undercoat material layer and the finishing material layer is 0.1 mm (100 μm) or larger.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a coating method for a concrete substrate and a coating film laminate obtained by the coating method.

Background Art

[0002] Conventionally, as a material constituting the outer wall of a building, a concrete-based material such as a precast concrete plate has been used.

[0003] In such a concrete-based material, coating is also performed on its surface to impart aesthetic properties. For example, Patent Document 1 discloses that coating is performed on a concrete surface using a water repellent, a base conditioner, a filler, a topcoat paint, and the like.

[0004] On the other hand, in order to increase the strength and the like of a concrete-based material, it is known to mix metal fibers into a cement composition containing cement, inorganic powder, etc. and cure it (for example, Patent Document 2).

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] " However, when coating the surface of a cement composition-based material containing metal fibers as in Patent Document 2, rust may occur over time, and the aesthetic properties of the coating film may be impaired.

[0007] The present invention has been made in view of such problems, and an object thereof is to provide a coating method capable of suppressing the generation of rust and forming a coating film that can maintain aesthetic appearance over a long period of time on a concrete substrate containing metal fibers, and a coating film laminate obtained by the coating method.

Means for Solving the Problems

[0008] As a result of intensive studies to solve the above problems, the present inventor has found that, for a concrete substrate containing metal fibers, after applying a primer to form a primer layer, a finish material is applied to form a finish material layer, and by using a coating method in which the average dry film thickness of a coating film layer including the primer layer and the finish material layer is adjusted within a specific range, the generation of rust can be suppressed, and a coating film laminate that can maintain aesthetic appearance over a long period of time can be obtained, and the present invention has been completed.

[0009] That is, the present invention relates to a coating method for a concrete substrate, wherein the concrete substrate contains metal fibers, and after applying a primer to the concrete substrate to form a primer layer, a finish material is applied to form a finish material layer, and the average dry film thickness of a coating film layer including the primer layer and the finish material layer is 0.1 mm (100 μm) or more.

[0010] In the coating method of the present invention, it is preferable that the finish material is at least one selected from the group consisting of a main material, an intermediate coating material, and a top coating material.

[0011] In the coating method of the present invention, it is preferable that the main material contains at least a resin and an extender pigment as a pigment, and contains 30 to 500 parts by mass of the extender pigment with respect to 100 parts by mass of the solid content of the resin.

[0012] In the coating method of the present invention, it is preferable that the elongation rate of the finish material layer is 30 to 500%.

[0013] The present invention relates to a coated film laminate characterized by being obtained by the above-described coating method. [Effects of the Invention]

[0014] According to the painting method of the present invention, it is possible to obtain a coated laminate on a concrete substrate containing metal fibers that can suppress the occurrence of rust and maintain its aesthetic appearance for a long period of time, making it useful. [Modes for carrying out the invention]

[0015] The embodiments for carrying out the present invention will be described in detail below.

[0016] [Concrete surface] The present invention relates to a coating method for a concrete substrate, characterized in that the concrete substrate contains metal fibers. The inclusion of metal fibers in the concrete substrate enhances its strength (compressive strength, flexural strength, cracking strength, etc.) and durability, making it highly useful.

[0017] The aforementioned concrete substrate is characterized by containing metal fibers. Such a concrete substrate is obtained by hardening a mixture of cement, aggregate, admixture, metal fibers, and water, and its strength, durability, etc., can be enhanced by the action of the metal fibers. Examples of such concrete substrates include metal fiber-containing precast concrete.

[0018] Examples of the aforementioned metal fibers include steel fibers, plated steel fibers, and stainless steel fibers. These can be used individually or in combination of two or more types.

[0019] The length of the metal fibers is preferably 2 to 80 mm, the diameter of the metal fibers is preferably 0.01 to 1 mm, and the aspect ratio (length of metal fibers / diameter of metal fibers) is preferably 10 to 200. Furthermore, the content ratio of the metal fibers in the concrete substrate is preferably 0.1 to 10% by mass.

[0020] The concrete substrate may further contain organic fibers. Examples of the organic fibers include polypropylene fibers, vinylon fibers, ethylene vinyl alcohol copolymer fibers, nylon fibers, cellulose fibers, polyacetal fibers, acrylic fibers, polyethylene fibers, aqueous vinylon fibers, and jute fibers. These can be used individually or in combination of two or more.

[0021] [Undercoat layer] The present invention relates to a painting method characterized by applying a primer to the concrete substrate to form a primer layer. The primer plays a role in ensuring adhesion between the concrete substrate and the finishing material.

[0022] The aforementioned undercoat material may contain a resin. Examples of such resins include vinyl chloride resin, epoxy resin, acrylic resin, urethane resin, acrylic silicone resin, or composite resins thereof. These can be used individually or in combination of two or more. Examples of such resin forms include water-soluble resins, water-dispersible resins (resin emulsions), solvent-soluble resins, solvent-free resins, non-water-dispersible resins, and powder resins. Furthermore, these resins may also have crosslinking reactivity.

[0023] As the resin in the aforementioned primer, epoxy resin is particularly preferred. Examples of the epoxy resin include bisphenol type epoxy resins such as bisphenol A type epoxy resin and bisphenol F type epoxy resin, phenol novolac type epoxy resins such as phenol novolac type bisphenol A epoxy resin and phenol novolac type bisphenol F epoxy resin, novolac type epoxy resins such as cresol novolac type epoxy resin and bisphenol A novolac type epoxy resin, alicyclic epoxy resin, hydrogenated bisphenol A type epoxy resin, guccidyl ether type epoxy resin, bisphenol S type epoxy resin, biphenyl type epoxy resin, dicyclo type epoxy resin, naphthalene type epoxy resin, butadiene-based epoxy resin, ε-caprolactone-modified epoxy resin, thiol-based epoxy resin, amine-modified epoxy resin, rubber-modified epoxy resin, urethane-modified epoxy resin, polyol-modified epoxy resin, fatty acid-modified epoxy resin, and the like. These can be used individually or in combination of two or more.

[0024] When the epoxy resin is used as the primer, an amine curing agent can be used as the curing agent. Examples of the amine curing agent include polyamine compounds such as aliphatic polyamines, alicyclic polyamines, aromatic polyamines, heterocyclic polyamines, aliphatic polyamides, alicyclic polyamides, aromatic polyamides, aliphatic polyamidoamines, alicyclic polyamidoamines, and aromatic polyamidoamines. These can be used individually or in combination of two or more.

[0025] In addition to the above components, the aforementioned primer may contain, for example, coloring pigments, extender pigments, rust inhibitors, plasticizers, preservatives, fungicides, algaecides, antibacterial agents, defoaming agents, leveling agents, coupling agents, wetting agents, pigment dispersants, surfactants, anti-settling agents, anti-sagging agents, matting agents, catalysts, curing accelerators, ultraviolet absorbers, light stabilizers, antioxidants, etc., within a range that does not significantly impair the effects of the present invention.

[0026] As the aforementioned primer, a rust-preventive primer can be used. As the aforementioned rust-preventive primer, one containing resin and a rust inhibitor can be used. By using the aforementioned rust-preventive primer, the effect of suppressing the occurrence of rust caused by metal fibers in the concrete substrate can be enhanced.

[0027] Commercially available or known materials can be used as the rust inhibitor. Specifically, examples include phosphate-based rust inhibitors such as zinc phosphate, iron phosphate, aluminum phosphate, magnesium phosphate, zirconium phosphate, manganese phosphate, and calcium phosphate; silicate-based rust inhibitors such as potassium silicate, calcium silicate, strontium silicate, barium silicate, titanium silicate, aluminum silicate, and magnesium silicate; phosphite-based rust inhibitors such as zinc phosphite, iron phosphite, and aluminum phosphite; molybdate-based rust inhibitors such as calcium molybdate, aluminum molybdate, and barium molybdate; vanadium-based rust inhibitors such as vanadium oxide; and chromate-based rust inhibitors such as strontium chromate, zinc chromate, calcium chromate, potassium chromate, and barium chromate. These can be used individually or in combination of two or more.

[0028] The rust inhibitor can be mixed with 100 parts by mass of the resin (solid content) in a ratio of preferably 1 to 150 parts by mass, more preferably 5 to 100 parts by mass. If the ratio of the rust inhibitor is within the above range, a sufficient effect of suppressing rust generation caused by metal fibers in the concrete substrate can be obtained.

[0029] The aforementioned primer layer can be formed by applying (coating) the primer described above and allowing it to dry.

[0030] The painting (coating) method can be appropriately employed, for example, spray painting, roller painting, or brush painting. Drying can be carried out at room temperature (preferably 0 to 40°C), and can also be carried out by heating if necessary.

[0031] The average dry film thickness of the aforementioned undercoat layer is preferably 5 μm or more, more preferably 10 to 100 μm, and even more preferably 15 to 80 μm.

[0032] The present invention relates to a painting method in which, after applying a primer to the concrete substrate to form a primer layer, a putty treatment can be applied to the pores on the surface of the primer layer before applying the finishing material to form a finishing layer. By performing such a putty treatment, the effect of suppressing the occurrence of rust caused by metal fibers in the concrete substrate can be further enhanced. The putty treatment can be performed by filling the pores on the surface of the primer layer with putty material.

[0033] As the putty material, various resins can be used as the main component. For example, silicone-based putty material, modified silicone-based putty material, polysulfide-based putty material, modified polysulfide-based putty material, epoxy-based putty material, acrylic urethane-based putty material, polyurethane-based putty material, acrylic-based putty material, SBR-based putty material, butyl rubber-based putty material, etc., can be used.

[0034] As the putty material, it is preferable to use an epoxy-based putty material mainly composed of epoxy resin. In such an epoxy-based putty material, an amine curing agent can be used as the curing agent. The epoxy resin and the amine curing agent can be the same as those exemplified in the undercoat material.

[0035] As the putty material, in addition to the various resins mentioned above, a material containing fillers, coloring pigments, etc., can be used.

[0036] Examples of the aforementioned fillers include calcium carbonate, clay, talc, mica, kaolin, zeolite, diatomaceous earth, and one or more of these can be used.

[0037] The ratio of the filler is preferably 50 to 400 parts by mass, more preferably 80 to 300 parts by mass, per 100 parts by mass (solid content) of the resin. If the ratio of the filler is within the above range, it is preferable in terms of workability, rust resistance, etc.

[0038] Examples of the aforementioned coloring pigments include titanium dioxide, zinc oxide, aluminum oxide, carbon black, graphite, black iron oxide, iron-chromium composite oxide, manganese-bismuth composite oxide, manganese-yttrium composite oxide, iron-manganese composite oxide, iron-copper-manganese composite oxide, iron-chromium-cobalt composite oxide, copper-chromium composite oxide, copper-manganese-chromium composite oxide, red iron oxide, molybdate orange, permanent red, permanent carmine, anthraquinone red, perylene red, quinacridone red, yellow iron oxide, titanium yellow, first yellow, benzoimidazolone yellow, chromium green, cobalt green, phthalocyanine green, ultramarine, Prussian blue, cobalt blue, phthalocyanine blue, quinacridone violet, and dioxazine violet. By appropriately selecting and using one or more of these coloring pigments, the color tone of the putty material can be set.

[0039] It is desirable that the color tone of the putty material differs from that of the primer. This ensures that the putty material is properly applied and is also preferable in terms of rust resistance.

[0040] The color difference (△E) between the putty material and the primer is preferably 3 or more, and more preferably 5 or more. Specifically, the putty material and the primer are applied to a standard white sheet at a rate of 0.2 kg / m². 2 The film length (L) of the coating after painting, placing the painted surface horizontally, and drying for 48 hours under standard conditions (temperature 23°C, relative humidity 50%) is... * value, a * value, b * The value (average of three measurement points) can be calculated using the following formula: L * value, a * value, b * The value is L according to CIE (International Commission on Illumination) 1976 (JIS Z8729).* a * b * The L value in colorimetry * value, a * value, b * values, and can be measured using a color difference meter for colors. <Formula> ΔE ={(L * 1 - L * 2) 2 +(a * 1 - a * 2) 2 +(b * [[ID= / 27]]1 - b * 2) 2} 0.5 [[ID= / 34]](In the formula, L * 1, a * / 1, b * 1 each represent the L<00 / / 00027>, a * , b * of the primer, and L * 2, a * 2, b * 2 each represent the L * , a * , b * of the putty. )

[0041] When filling the putty into the holes, a spatula or the like can be used. The putty treatment may be performed at least on the holes on the surface of the primer layer, but can also be performed on the entire surface of the primer layer.

[0042] In the present invention, due to the application of the primer, the holes caused by the surface state of the concrete material are likely to be made apparent. Therefore, the holes to be the target of the putty treatment can be easily specified, and the putty treatment can be efficiently performed, which is also suitable in terms of rust resistance.

[0043] The amount of the putty used may be appropriately set according to the state of the holes or the like, but is preferably 0.2 kg / m 2 or less, more preferably 0.01 - 0.1 kg / m 2 .

[0044] <00002 / / 13>[Topcoat layer] The present invention's painting method is characterized by forming a finishing layer by applying a finishing material to a primer layer. This application of the finishing material allows for the application of desired colors, enhances the suppression of rust formation caused by metal fibers in the concrete substrate, and maintains aesthetic appeal over a long period. Furthermore, it can improve physical properties such as waterproofing, weather resistance, and stain resistance.

[0045] In the painting method of the present invention, the average dry film thickness of the paint film layer, including the undercoat layer and the finish layer, is 0.1 mm (100 μm) or more, preferably 0.15 mm (150 μm) or more. When the average dry film thickness of the paint film layer is within the above range, rust generation caused by metal fibers in the concrete substrate can be sufficiently suppressed, and the aesthetic appearance can be maintained for a long period of time. The upper limit of the average dry film thickness of the paint film layer is not particularly limited, but is preferably 3 mm or less, more preferably 2 mm or less.

[0046] The finishing material can include, for example, a resin and a pigment. Examples of resins in the finishing material include vinyl acetate resin, polyester resin, alkyd resin, vinyl chloride resin, epoxy resin, acrylic resin, urethane resin, acrylic silicone resin, fluororesin, etc., or composite resins thereof. Examples of such resin forms include water-soluble resins, water-dispersible resins (resin emulsions), solvent-soluble resins, solvent-free resins, non-aqueous-dispersible resins, powder resins, etc., and among these, one or more selected from water-soluble resins, water-dispersible resins, solvent-soluble resins, and non-aqueous-dispersible resins are preferred. Furthermore, these resins may also have crosslinking reactivity.

[0047] As the aforementioned pigment, coloring pigments and / or extender pigments can be used.

[0048] Examples of the aforementioned coloring pigments include titanium dioxide, zinc oxide, aluminum oxide, carbon black, graphite, black iron oxide, iron-chromium composite oxide, manganese-bismuth composite oxide, manganese-yttrium composite oxide, iron-manganese composite oxide, iron-copper-manganese composite oxide, iron-chromium-cobalt composite oxide, copper-chromium composite oxide, copper-manganese-chromium composite oxide, red iron oxide, molybdate orange, permanent red, permanent carmine, anthraquinone red, perylene red, quinacridone red, yellow iron oxide, titanium yellow, first yellow, benzoimidazolone yellow, chromium green, cobalt green, phthalocyanine green, ultramarine, navy blue, cobalt blue, phthalocyanine blue, quinacridone violet, dioxazine violet, aluminum pigment, pearl pigment, etc. These can be used individually or in combination of two or more.

[0049] Examples of the aforementioned extender pigments include heavy calcium carbonate, light calcium carbonate, kaolin, clay, pottery clay, china clay, diatomaceous earth, hydrated fine silica, talc, barite powder, barium sulfate, precipitated barium sulfate, barium carbonate, magnesium carbonate, silica powder, and aluminum hydroxide. These can be used individually or in combination of two or more.

[0050] The finishing material may contain various components other than those mentioned above, as long as the effects of the present invention are not significantly impaired. Examples of such components include thickeners, film-forming aids, leveling agents, coupling agents, wetting agents, plasticizers, antifreeze agents, pH adjusters, extender pigments, preservatives, antifungal agents, antialgal agents, antibacterial agents, dispersants, defoaming agents, adsorbents, fibers, crosslinking agents, ultraviolet absorbers, light stabilizers, antioxidants, decontamination agents, hydrophilic agents, water repellents, catalysts, solvents, water, and the like.

[0051] The finishing material can be manufactured by uniformly mixing the resin, the pigment, and, if necessary, the various components mentioned above, using conventional methods. The finishing material can be in the form of, for example, a one-component, two-component, or multi-component type.

[0052] The aforementioned finishing material can be one or more types of finishing materials. Preferably, such a finishing material is at least one selected from the group consisting of a main material, an intermediate coating material, and a top coating material.

[0053] The aforementioned topcoat material forms a coating film on the surface side of the finishing material layer, plays a role in providing color, and exhibits physical properties such as weather resistance and stain resistance.

[0054] The resin used for the topcoat is preferably one or more types selected from acrylic resin, urethane resin, acrylic silicone resin, fluororesin, etc.

[0055] The topcoat material is preferably one that contains a coloring pigment as a pigment. This makes it possible to impart a desired color.

[0056] The ratio of coloring pigment in the topcoat is preferably 1 to 500 parts by mass, more preferably 5 to 200 parts by mass, and even more preferably 10 to 150 parts by mass, per 100 parts by mass of resin solids. If the ratio of coloring pigment is within the above range, it is suitable in terms of coloring, weather resistance, etc.

[0057] As for the topcoat material, one that forms a coating film with a contact angle to water of 70° or less is preferable in terms of stain resistance and other properties. Such a topcoat material can be obtained, for example, by incorporating a low-staining agent, a hydrophilic agent, etc.

[0058] The degree of gloss (sheen) of the topcoat material can be set as appropriate. For example, materials exhibiting gloss levels such as high gloss, 70% gloss, 50% gloss, 30% gloss, and matte can be used.

[0059] The 60° specular gloss of the topcoat material is preferably greater than 15, and more preferably 20 or greater. Such a topcoat material is suitable in terms of rust resistance and other properties. The specular gloss of the topcoat material is obtained by applying the topcoat material to a glass plate using a film applicator with a gap of 150 μm, and then measuring the specular gloss (average value of 10 measurement points at a measurement angle of 60 degrees) after drying the coated surface horizontally under standard conditions (temperature 23°C, relative humidity 50%) for 48 hours.

[0060] The aforementioned intermediate coating material forms a coating film beneath the topcoat material and contributes to improving adhesion, opacity, etc. For example, when a fluororesin-based topcoat material is used as the topcoat material, an acrylic resin-based intermediate coating material, a urethane resin-based intermediate coating material, etc., can be used as the intermediate coating material.

[0061] The main material forms a coating film on the surface side of the undercoat layer and contributes to improving physical properties such as waterproofing, substrate conformability, adhesion, and strength, and is also suitable in terms of forming a thick film. The main material may contain at least a resin and a pigment.

[0062] The main resin material can preferably be one or more types selected from epoxy resin, acrylic resin, urethane resin, acrylic silicone resin, etc. Of the resins used as the main material, the acrylic resin and acrylic silicone resin are preferred to have a glass transition temperature (hereinafter also referred to as "Tg") of 50°C or lower, more preferably 20°C or lower, and even more preferably 0°C or lower, from the viewpoint of rust suppression effect, waterproofing, and substrate conformability. The glass transition temperature is a value that can be calculated using Fox's formula. Furthermore, among the resins of the main material, flexible epoxy resins are particularly preferred as the epoxy resin, in terms of rust suppression effect, waterproofing properties, and substrate conformability.

[0063] Examples of the aforementioned flexible epoxy resins include aliphatic-modified epoxy resins, butadiene-based epoxy resins, ε-caprolactone-modified epoxy resins, thiol-based epoxy resins, amine-modified epoxy resins, rubber-modified epoxy resins, urethane-modified epoxy resins, polyol-modified epoxy resins, and fatty acid-modified epoxy resins. These can be used individually or in combination of two or more. Among these, urethane-modified epoxy resins are preferred.

[0064] The pigment in the main material is preferably one that contains an extender pigment. The ratio of the extender pigment in the main material is preferably 30 to 500 parts by mass, more preferably 50 to 400 parts by mass, per 100 parts by mass of resin solids, from the viewpoint of waterproofing, substrate conformability, adhesion, strength, etc. The main material containing an extender pigment is also advantageous in terms of forming a thick coating film.

[0065] The pigment in the main material may include coloring pigments in addition to extender pigments. The volume concentration of the pigment in the main material is preferably 10 to 70%, more preferably 20 to 60%. Such a volume concentration of pigment is suitable in terms of waterproofing, substrate conformability, adhesion, strength, and thickness of the coating film.

[0066] In the present invention, a finishing material layer can be formed by applying the finishing material (for example, a main material, an intermediate coating material, a top coating material, etc.), and specifically, the following methods can be employed. (1) Apply only the topcoat material as the finishing material to form a finishing layer. (2) As a finishing material, an intermediate coating material and a top coating material are applied to form a finishing layer. (3) As a finishing material, the main material and the top coat material are applied to form a finishing layer. (4) As a finishing material, the main material, intermediate coating material, and top coating material are applied to form a finishing material layer.

[0067] In applying the aforementioned finishing material, known painting tools can be used. Examples of such painting tools include sprayers, rollers, brushes, and the like.

[0068] The amount of the finishing material applied should be set appropriately according to the type of finishing material, the type of painting equipment, etc.

[0069] When applying the finishing material, it may be diluted as needed. The finishing material can be dried at room temperature (preferably 0-40°C), and may also be heated if necessary.

[0070] In the present invention, it is preferable that the finishing material layer is elastic. The elasticity of the finishing material layer further enhances the effect of suppressing rust formation caused by metal fibers in the concrete substrate, allowing for sufficient maintenance of aesthetic appearance over a long period. Furthermore, it can also further improve physical properties such as waterproofing and substrate conformability.

[0071] If the finishing layer is elastic, the elongation rate of the finishing layer is preferably 30-500%, more preferably 50-400%, and even more preferably 100-300%. The elongation rate is the value measured by the method of "elongation test at 20°C" in JIS A6909 "7.29 Elongation test".

[0072] [Laminated coating] The present invention is characterized by obtaining a coated laminate on a concrete substrate by the aforementioned coating method. Such a coated laminate can suppress the occurrence of rust caused by metal fibers in the concrete substrate and maintain its aesthetic appearance for a long period of time. [Examples]

[0073] The following examples illustrate the features of the present invention. However, the present invention is not limited to the examples provided herein.

[0074] The following materials were prepared as the concrete substrate, primer, main agent, intermediate coat, and topcoat.

[0075] [Concrete surface] • Substrate 1: Precast concrete containing metal fibers • Substrate 2: Precast concrete (without metal fibers)

[0076] [Undercoat material] • Primer 1: Solvent-based primer (a two-component epoxy resin primer consisting of a main component mainly composed of soluble epoxy resin and aromatic solvent, and an amine curing agent) • Primer 2: Water-based primer (a two-component epoxy resin primer consisting of an epoxy resin emulsion, a main component mainly composed of water, and an amine curing agent) • Primer 3: Rust-preventive solvent-based primer (a two-component epoxy resin rust-preventive primer consisting of a main component comprising soluble epoxy resin, rust inhibitor, coloring pigment, extender pigment, and aromatic solvent, and an amine curing agent. Color: reddish-brown. Rust inhibitor ratio: 28 parts by mass per 100 parts by mass of resin solids.)

[0077] [Main material] • Main component 1: Solvent-based main component (a two-component epoxy resin elastic main component consisting of a main component mainly composed of urethane-modified epoxy resin, coloring pigment, extender pigment, and aromatic solvent, and an amine curing agent. Pigment volume concentration: 30%) • Main component 2: Water-based main component (a one-component acrylic resin elastic main component mainly consisting of acrylic resin emulsion (Tg -30℃), coloring pigment, extender pigment, and water. Pigment volume concentration 55%)

[0078] [Intermediate coating material] • Intermediate coating material 1: Solvent-based intermediate coating material (a two-component urethane resin intermediate coating material consisting of a main component mainly composed of soluble polyol, coloring pigment, and aromatic solvent, and a polyisocyanate curing agent.) • Intermediate coating material 2: Water-based intermediate coating material (a one-component urethane resin intermediate coating material mainly composed of acrylic urethane resin emulsion, coloring pigment, and water)

[0079] [Top coat material] • Topcoat 1: Solvent-based topcoat (a two-component fluororesin topcoat consisting of a main component mainly composed of soluble fluoropolyol, colored pigment, and aromatic solvent, and a hardener mainly composed of polyisocyanate and silicate compounds. 60° specular gloss 82) • Topcoat 2: Water-based topcoat (a two-component fluororesin topcoat consisting of a main component mainly composed of fluororesin emulsion, coloring pigment, and water, and a hardener mainly composed of silicate compounds. 60° mirror gloss 80)

[0080] (Example 1) Apply 0.12 kg / m² of primer to the substrate. 2 The surface was spray-painted and allowed to dry for 24 hours to form a primer layer. Main material 1 was then applied to this primer layer at a rate of 0.3 kg / m². 2 The paint was spray-applied and allowed to dry for 24 hours, then the intermediate coating material 1 was applied at a rate of 0.1 kg / m². 2 After spray painting and drying for 24 hours, apply topcoat 1 at a rate of 0.1 kg / m². 2 The material was spray-painted and allowed to dry for 168 hours to form a finishing layer (with an elongation rate of 130%). The average dry film thickness of the paint film layer was 160 μm.

[0081] (Example 2) The application rate for main material 1 is 0.15 kg / m². 2 Except for the change made, the test specimens were prepared in the same manner as in Example 1 (elongation of the finishing material layer: 125%, average dry film thickness of the paint coating layer: 120 μm).

[0082] (Example 3) The test specimens were prepared in the same manner as in Example 1, except that primer 2, intermediate coat 2, and topcoat 2 were used as the primer, intermediate coat, and topcoat, respectively (elongation of the finishing material layer: 130%, average dry film thickness of the paint film layer: 160 μm).

[0083] (Example 4) Apply 0.12 kg / m² of primer to the substrate. 2 The surface was spray-painted and allowed to dry for 24 hours to form a primer layer. The main material 2 was then applied to this primer layer at a rate of 1.5 kg / m². 2 The paint was spray-applied and allowed to dry for 24 hours, then the intermediate coating material 1 was applied at a rate of 0.1 kg / m². 2 After spray painting and drying for 24 hours, apply topcoat 1 at a rate of 0.1 kg / m². 2The material was spray-painted and allowed to dry for 168 hours to form a finishing layer (with an elongation rate of 200%). The average dry film thickness of the paint film layer was 1 mm.

[0084] (Example 5) The test specimens were prepared in the same manner as in Example 3, except that primer 2, intermediate coat 2, and topcoat 2 were used as the primer, intermediate coat, and topcoat, respectively (elongation of the finishing material layer: 200%, average dry film thickness of the paint film layer: 1 mm).

[0085] (Example 6) The test specimens were prepared in the same manner as in Example 1, except that primer material 3 was used as the undercoat material (elongation of the finishing material layer: 130%, average dry film thickness of the paint film layer: 160 μm).

[0086] (Comparative Example 1) Apply 0.12 kg / m² of primer to the substrate. 2 The surface was spray-painted and allowed to dry for 24 hours to form a primer layer. Intermediate coat 1 was then applied to this primer layer at a rate of 0.1 kg / m². 2 After spray painting and drying for 24 hours, apply topcoat 1 at a rate of 0.1 kg / m². 2 The material was spray-painted and allowed to dry for 168 hours to form a finish layer (elongation of the finish layer was 90%). The average dry film thickness of the paint film layer was 80 μm.

[0087] (Comparative Example 2) Apply primer 2 at a rate of 0.12 kg / m² to the substrate 1. 2 The surface was spray-painted and allowed to dry for 24 hours to form a primer layer. Intermediate coat 2 was then applied to this primer layer at a rate of 0.1 kg / m². 2 After spray painting and drying for 24 hours, apply topcoat 2 at a rate of 0.1 kg / m². 2 The material was spray-painted and allowed to dry for 168 hours to form a finish layer (elongation of the finish layer was 95%). The average dry film thickness of the paint film layer was 80 μm.

[0088] (Reference example 1) Apply primer 1 to substrate 2 at a rate of 0.12 kg / m². 2The surface was spray-painted and allowed to dry for 24 hours to form a primer layer. Intermediate coat 1 was then applied to this primer layer at a rate of 0.1 kg / m². 2 After spray painting and drying for 24 hours, apply topcoat 1 at a rate of 0.1 kg / m². 2 The material was spray-painted and allowed to dry for 168 hours to form a finish layer (elongation of the finish layer was 90%). The average dry film thickness of the paint film layer was 80 μm.

[0089] (Evaluation of corrosion resistance) The test specimens obtained using the above method were subjected to a 120-cycle test in accordance with Cycle D of JIS K5600-7-9:2006 "Long-term durability of coatings - Cycle corrosion test method," and the number of rust spots on the surface of the test specimens was measured. The evaluation criteria are as follows. In the case of an A or B evaluation, the level was evaluated as being at a level that does not pose any problems in practical use. A: No rust occurred. B: Number of rust spots: 1-5 C: Number of rusted areas: 6-10 D: Number of rusted areas: 11 or more

[0090] (Evaluation of aesthetic appeal) Similar to the evaluation of corrosion resistance described above, each test specimen was subjected to a 120-cycle test in accordance with Cycle D of JIS K5600-7-9:2006 "Long-term durability of coatings - Cycle corrosion test method". The appearance of the test specimens before and after the test was then compared and observed to evaluate their aesthetics. The evaluation criteria are as follows. A and B ratings indicate that the specimen is at a level where there are no practical problems. A: No change in appearance B: Area contaminated by rust stains is less than 1% C: Area contaminated by rust stains: more than 1% but less than 5% D: Area contaminated by rust stains exceeds 5%

[0091] The results of the above evaluation are shown in Table 1 below.

[0092] [Table 1]

[0093] From the evaluation results in Table 1 above, it was confirmed that all examples exhibited excellent rust resistance and aesthetic appeal. On the other hand, in Comparative Examples 1 and 2, the thickness of the paint film layer was thin and fell below the desired range, resulting in rust formation. This indicated poor rust resistance, and furthermore, the rust formation resulted in poor aesthetic appeal, posing practical problems.

Claims

1. A method for painting a concrete substrate, The aforementioned concrete substrate contains metal fibers, After applying a primer to the aforementioned concrete substrate to form a primer layer, a finishing material is applied to form a finishing layer. Before applying the aforementioned finishing material to form the finishing material layer, putty treatment is performed on any pores on the surface of the primer layer. The average dry film thickness of the paint film layer, including the primer layer and the finish layer, is 0.1 mm (100 μm) or more. A painting method characterized in that the aforementioned undercoat material is a rust-preventive undercoat material.

2. The finishing material is at least one selected from the group consisting of a main material, an intermediate coating material, and a top coating material. The main material forms a coating film on the surface side of the undercoat layer. The aforementioned intermediate coating material forms a coating film below the aforementioned top coating material. The painting method according to claim 1, characterized in that the topcoat material forms a coating film on the surface side of the finishing material layer.

3. The main material includes at least a resin and an extender pigment as a pigment, The coating method according to claim 2, characterized in that it contains 30 to 500 parts by mass of the extender pigment with respect to 100 parts by mass of the solid content of the resin.

4. The painting method according to any one of claims 1 to 3, characterized in that the elongation rate of the finishing material layer is 30 to 500%.

5. The painting method according to any one of claims 1 to 4, characterized in that the color difference (△E) between the putty material used for the putty treatment and the primer material is 3 or more.

6. The pigment of the main material includes a coloring pigment in addition to the extender pigment, The painting method according to any one of claims 3 to 5, characterized in that the volume concentration of the pigment of the main material is 10 to 70%.

7. A coated laminate characterized by being obtained by the coating method described in any one of claims 1 to 6.

Images