JP2016186021A - Aqueous epoxy resin coating composition, coated body and method for producing coated body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an aqueous epoxy resin coating composition capable of forming a coating film with dry film thickness of 100 μm or thicker by one coating, the coating film having high anticorrosion property.SOLUTION: An aqueous epoxy resin coating composition at least includes (A) epoxy resin, (B) curative, (C) viscosity moderator, (D) pigment, and (E) water, and is a two pack aqueous epoxy resin coating composition configured to use by mixing the (A) epoxy resin and the (B) curative just before the use for coating. The content of coating film formation constituents in the aqueous epoxy resin coating composition is 55-75 mass%. The (C) viscosity moderator is at least one kind selected from a group consisting of a polyacrylic acid-based viscosity moderator and a polyurethane-based viscosity moderator.SELECTED DRAWING: None

Description

  The present invention relates to a water-based epoxy resin coating composition, a coated body using the water-based epoxy resin coating composition, and a method for producing the coated body, and in particular, a coating film having a dry film thickness of 100 μm or more by one coating. The present invention relates to a water-based epoxy resin coating composition that can be formed and can form a coating film having high corrosion resistance.

  Conventionally, the quality of organic solvent-based epoxy resin paints has been standardized in Japanese Industrial Standards and the like, and is widely used for the purpose of imparting corrosion resistance to structures such as bridges and plants. However, in recent years, there has been a strong demand for switching from conventional organic solvent-based epoxy resin paints to water-based epoxy resin paints from the viewpoint of preventing air pollution and saving resources.

  For example, Japanese Unexamined Patent Application Publication No. 2009-149791 (Patent Document 1) proposes an aqueous anticorrosive paint containing an epoxy resin emulsion and an anticorrosive coating method for applying the aqueous anticorrosive paint on a substrate surface. JP2013-199621A (Patent Document 2) discloses an aqueous epoxy resin coating composition containing an epoxy resin emulsion and an amine resin emulsion and having a viscosity at a specific shear rate adjusted within a specific range. Proposed.

JP 2009-149791 A JP2013-199621A

Conventionally, as one approach for improving the anticorrosion effect, there is a method of increasing the film thickness of a coating film formed on a substrate, specifically, a method of increasing the film thickness to 100 μm or more.
Using a water-based epoxy resin coating composition (Patent Documents 1 and 2) used as an undercoat for a structure, when forming a coating film with a film thickness of 100 μm or more, usually from the viewpoint of coating workability, A method of applying a water-based epoxy resin coating composition a plurality of times has been performed.
However, in order to shorten the coating process, there has been a demand for a paint that can be applied with a thick film by a single coating. As a method of thickening the coating film formed by one coating, there is a method of increasing the content of the coating film forming component in the coating, but when this method is applied to a conventional aqueous epoxy resin coating composition From the viewpoint of painting workability, there is a problem that it is difficult to obtain a smooth coating film.
In addition, when a coating film having a film thickness of 100 μm or more is formed by one coating with a water-based epoxy resin coating composition having a high coating film-forming component content, a water-based epoxy having a low coating film-forming component content is formed. There was a tendency for the anticorrosion performance to be inferior compared to the coating film in which the resin coating composition was applied several times.

  The object of the present invention is to solve the above-mentioned problems of the prior art and to form a coating film having a dry film thickness of 100 μm or more by a single coating and to form a coating film having high anticorrosion properties. The object is to provide a resin coating composition. Another object of the present invention is to provide a coated body using such a water-based epoxy resin coating composition and a method for producing the coated body.

  As a result of intensive studies to achieve the above object, the present inventor has formulated a specific viscosity modifier in a two-component water-based epoxy resin coating composition containing a large amount of coating film forming components. It has been found that a coating film having a dry film thickness of 100 μm or more can be formed by coating, and that the corrosion resistance of the coating film is also high, and the present invention has been completed.

  That is, the water-based epoxy resin coating composition of the present invention comprises (A) an epoxy resin, (B) a curing agent, (C) a viscosity modifier, (D) a pigment, and (E) water, and (A) an epoxy. A two-component water-based epoxy resin coating composition in which a resin and (B) a curing agent are mixed and used immediately before coating, and the content of the film-forming component in the water-based epoxy resin coating composition is 55 to 55 The viscosity adjusting agent (C) is at least one selected from the group consisting of a polyacrylic acid viscosity adjusting agent and a polyurethane viscosity adjusting agent.

  In a preferred example of the water-based epoxy resin coating composition of the present invention, the viscosity at a shear rate of 0.1 (1 / s) is 50 to 500 (Pa · s, 23 ° C.), and the shear rate is 1000 (1 / s). Viscosity at 0.01 to 1 (Pa · s, 23 ° C.).

  In another preferable example of the water-based epoxy resin coating composition of the present invention, the (D) pigment is selected from the group consisting of talc, mica, kaolin clay, glass flakes, and mica-like iron oxide, and the aspect ratio is It contains at least one scale pigment that is 1.2 to 100, and the ratio of the scale pigment in the coating film forming component is 3 to 30% by mass.

  Furthermore, the scale ratio of the scaly pigment is preferably 20-100.

  Moreover, the coated body of the present invention is a coated body including a base material and a coating film disposed on the surface of the base material, and the coating film is formed of the above-described aqueous epoxy resin coating composition. It is characterized by that.

  Furthermore, the first method for producing a coated body of the present invention is characterized in that the above-described aqueous epoxy resin coating composition is applied to the surface of a substrate.

  Furthermore, the second production method of the coated body of the present invention is a method in which the above-mentioned aqueous epoxy resin coating composition is coated on the surface of a substrate to form an undercoat film, and then the surface of the undercoat film is overcoated. Is coated to form a top coat film.

  Furthermore, a third method for producing a coated body of the present invention is to coat the above-mentioned aqueous epoxy resin coating composition on the surface of a substrate to form an undercoat film, and then apply an intermediate coat onto the surface of the undercoat film. A paint is applied to form an intermediate coating film, and then a top coating is applied to the surface of the intermediate coating film to form a top coating film.

  According to the water-based epoxy resin paint composition of the present invention, a water-based epoxy resin paint capable of forming a coating film having a dry film thickness of 100 μm or more by one coating and having a high anticorrosion property. A composition can be provided.

  According to the coated body of the present invention, a coated body using such a water-based epoxy resin coating composition can be provided. According to the method for producing a coated body of the present invention, such a water-based epoxy resin coating composition is used. A method for producing a coated body can be provided.

  Hereinafter, the water-based epoxy resin coating composition of the present invention (hereinafter, also simply referred to as the coating composition of the present invention) will be described in detail. The water-based epoxy resin coating composition of the present invention comprises (A) an epoxy resin, (B) a curing agent, (C) a viscosity modifier, (D) a pigment, and (E) water, and (A) an epoxy resin and (B) A two-component water-based epoxy resin coating composition in which a curing agent is mixed and used immediately before coating, and the content of the film-forming component in the water-based epoxy resin coating composition is 55 to 75 masses. The (C) viscosity modifier is at least one selected from the group consisting of a polyacrylic acid viscosity modifier and a polyurethane viscosity modifier.

  In the water-based epoxy resin coating composition of the present invention, the content of the coating film-forming component needs to be 55 to 75% by mass, preferably 60 to 75% by mass, and 65 to 75% by mass. Is more preferable. When the content of the coating film forming component is 55 to 75% by mass, it is possible to form a coating film having a dry film thickness of 100 μm or more by a single coating when good coating workability is realized. In the present invention, the coating film forming component refers to a component remaining when the coating composition is dried at 130 ° C. for 40 minutes.

  The coating composition of the present invention has a viscosity of 50 to 500 (Pa · s, 23 ° C.) at a shear rate of 0.1 (1 / s) and a viscosity of 0.01 to 1,000 at a shear rate of 1000 (1 / s). 1 (Pa · s, 23 ° C.) is preferable. By adjusting within the above specified range, the coating workability of the coating composition can be improved, and a smooth coating film having a dry film thickness of 100 μm or more can be formed by one coating.

  In the water-based epoxy resin coating composition of the present invention, the reason why the viscosity is defined based on two shear rates of 0.1 (1 / s) and 1000 (1 / s) is 0.1 (1 / The shear rate of s) refers to the viscosity of the paint immediately after coating, the shear rate of 1000 (1 / s) refers to the viscosity of the paint at the time of brush coating, and the viscosity of the paint immediately after coating from the time of coating is sagging and leveling. This is because it correlates with gender. In addition, as a method for adjusting the viscosity of the water-based epoxy resin coating composition of the present invention within the above-specified range, a viscosity adjusting agent described later, a method for adjusting the amount of water, and the like can be used.

  The coating composition of the present invention is required to contain (A) an epoxy resin. Epoxy resins generally have high adhesion to metal substrates, and also have an effect of shielding the substrate from environmental factors (for example, water, oxygen, etc.) that affect metal corrosion (shielding effect). It is an excellent resin.

  The epoxy resin is preferably a resin having at least two epoxy groups in one molecule. For example, it is obtained by reacting a polyhydric alcohol or polyhydric phenol with a halohydrin. Bisphenol A type epoxy resin, halogenated bisphenol A type epoxy resin, novolak type epoxy resin, polyglycol type epoxy resin, bisphenol F type epoxy resin, epoxidized oil, 1,6-hexanediol diglycidyl ether and neopentyl glycol And diglycidyl ether. Among these, bisphenol A type epoxy resin and bisphenol F type epoxy resin are preferable from the viewpoints of mechanical durability and corrosion resistance of the coating film, adhesion to the substrate, and the like. In addition, these epoxy resins may be used independently and may be used in combination of 2 or more type.

  In addition, the epoxy resin usually has an epoxy equivalent of preferably 100 to 1,000 g / eq, more preferably 160 to 980 g / eq, from the viewpoint of the finish of the coating film to be formed, curability, corrosion resistance, and the like. 160 to 550 g / eq is more preferable. If the epoxy equivalent is less than 100 g / eq, sufficient film properties may not be obtained. On the other hand, if the epoxy equivalent is greater than 1,000 g / eq, the leveling property is lowered and a uniform coating is obtained. There is a risk of not being able to.

  The epoxy resin is preferably blended in the form of an epoxy resin emulsion or an epoxy resin dispersion. In the present invention, the epoxy resin emulsion means an emulsion in which an epoxy resin is dispersed in an aqueous medium such as water, and the epoxy resin dispersion means an epoxy resin in an aqueous medium such as water. It means a dispersed liquid. The epoxy resin emulsion is not particularly limited, but is prepared by emulsifying the epoxy resin in an aqueous medium such as water by a normal forced emulsification method (a method using an emulsifier and a high-speed stirrer). Here, as the emulsifier, for example, a polyoxyethylene alkylphenol ether-based nonionic surfactant, a polyether such as a polyoxyethylene / polyoxypropylene block copolymer, or at least the nonionic surfactant and the polyether Examples include adducts of one and a diisocyanate compound. These emulsifiers may be used alone or as a blend of two or more. Moreover, as a commercial item of an epoxy resin emulsion, for example, Eporation EA1, 2, 3, 7, 12, 20, 55 and HD2 (made by Henkel Japan); Yukaresin KE-002, KE-116, E-1022, KE -301C (manufactured by Yoshimura Oil Chemical Co., Ltd.); Adeka Resin EM-101-50 (manufactured by Adeka Company); jER-W3435R67, W1155R55 (manufactured by Mitsubishi Chemical Corporation), and the like. On the other hand, examples of commercially available epoxy resin dispersions include Beckpox EP2381 (manufactured by Ornex); EPI-REZ6530-WH-53 (manufactured by Momentive).

  The coating composition of the present invention needs to contain (B) a curing agent. Here, the curing agent is not particularly limited as long as it is an epoxy resin curing agent, but an amine compound is preferable, and a polyamine compound containing two or more amino groups in one molecule and having a molecular weight of 120 or more. Further preferred. Examples of the polyamine compound include ethylenediamine, trimethylenediamine, tetramethylenediamine, pentamethylenediamine, triaminopropane, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, isophoronediamine, and 1,3-bisaminomethylcyclohexane. Aliphatic polyamines; aromatic polyamines such as phenylenediamine, metaxylylenediamine, paraxylylenediamine, and diaminodiphenylmethane; such as polyoxyethylenediamine, polyoxypropylenediamine, triethyleneglycoldiamine, and tripropyleneglycoldiamine Examples include other polyamine compounds and modified polyamine compounds obtained by modifying the amino groups of these polyamine compounds. A known method can be used for the modification of the polyamine compound. Examples of the modification reaction include amidation of an amino group, Mannich reaction of an amino group and a carbonyl compound, addition reaction of an amino group and an epoxy group, and the like. It is done. Here, a modified polyamine compound in which an epoxy group or the like is added to an amino group is referred to as an adduct type modified polyamine compound, and an epoxy adduct type modified polyamine compound in which an epoxy group is added to an amino group is preferable from the viewpoint of corrosion resistance. . In addition, these amine compounds may be used independently and may be used in combination of 2 or more type.

  The amine compound is preferably blended in the form of an amine compound emulsion, an amine compound dispersion or an amine compound aqueous solution. In the present invention, the amine compound emulsion means an emulsion in which the amine compound is dispersed in an aqueous medium such as water, and the amine compound dispersion means an aqueous medium in which the amine compound is water or the like. It means a dispersion liquid dispersed in the medium. In addition, as said amine compound, the commercial item available in the form of an emulsion, a dispersion, or aqueous solution can be used conveniently.

  In the coating composition of the present invention, when the curing agent is an amine compound, the blending ratio of the curing agent is an amine with respect to 1 equivalent of the epoxy group of the epoxy resin from the viewpoint of the curability and corrosion resistance of the coating film. The active hydrogen of the compound is usually in the range of 0.5 to 2.0 equivalents, particularly preferably in the range of 0.6 to 1.2 equivalents.

  In the coating composition of the present invention, the total ratio of the epoxy resin and the curing agent in the coating film forming component is preferably 30 to 50% by mass, and more preferably 30 to 45% by mass.

  The coating composition of the present invention needs to contain (C) a viscosity modifier. Here, (C) the viscosity modifier is at least one viscosity modifier selected from the group consisting of a polyacrylic acid viscosity modifier and a polyurethane viscosity modifier. The present inventor has found that when such a viscosity modifier (C) is used, a coating film having a high anticorrosion property can be obtained even when a coating film having a dry film thickness of 100 μm or more is formed by one coating. . Since the polyacrylic acid viscosity modifier and the polyurethane viscosity modifier are polymers as will be described later, they are more hydrophobic than other viscosity modifiers. For this reason, when a polyacrylic acid-based viscosity modifier or a polyurethane-based viscosity modifier is used, water hardly penetrates into the formed coating film, and water resistance hardly occurs. This may affect the achievement of high corrosion resistance.

  Examples of the polyacrylic acid viscosity modifier include amine salts, amide salts, or sodium salts of polymers obtained by polymerizing one or more acrylic components selected from acrylic acid or esters thereof, amides, and nitriles. And having a plurality of carboxyl groups or salts thereof in the molecule. Specific examples include sodium polyacrylate, Disparon AQ-001, 002 (manufactured by Enomoto Kasei Co., Ltd., aqueous dispersion of amine salt of acrylic polymer); Chixol K-130B, W-400LP (manufactured by Kyoei Co., polyacrylic acid) Examples thereof include polyacrylates such as aqueous dispersions of aliphatic polyamides. Polyurethane viscosity modifiers include compounds that have urethane and hydrophilic moieties formed from the reaction of hydroxyl and isocyanate groups in the molecule, and urea and hydrophilic moieties formed from the reaction of amino and isocyanate groups. The compound which has in a molecule | numerator, or a urethane part, a urea part, and a hydrophilic part in a molecule | numerator is mentioned. As specific examples, SN thickeners 612, 625, and 660T (manufactured by Sannopco, water dispersion of polyether polyurethane); BYK-420 (manufactured by BYK, water dispersion of modified urea urethane); ASA ER- 3, 90 (manufactured by Ito Oil Co., Ltd., water dispersion of polyether polyurethane) and the like. These viscosity modifiers may be used alone or in combination of two or more. In addition, as a viscosity modifier, although a commercial item can be used conveniently, from the viewpoint of the storage stability of a coating material, the thing neutralized previously or the thing which does not need the neutralization process is preferable.

  In the coating composition of the present invention, the content of the (C) viscosity modifier varies depending on the type of the viscosity modifier, but is preferably 0.01 to 2.0% by mass, preferably 0.01 to 1.%. More preferably, it is 0% by mass. When content of the viscosity modifier in the coating composition of this invention exceeds 2.0 mass%, there exists a possibility that corrosion resistance and coating workability may fall.

  The coating composition of the present invention is required to contain (D) a pigment. Here, (D) the pigment contains at least one scaly pigment having an aspect ratio of 1.2 to 100 selected from the group consisting of talc, mica, kaolin clay, glass flakes, and mica-like iron oxide. Is preferred. The scale-like pigment shows the effect of inhibiting the invasion of corrosion factors such as water, oxygen and chloride and the effect of reducing the internal stress of the coating film because of its shape. By reducing the internal stress of the coating film, the adhesion of the coating film to the substrate can be further improved. In addition, the coating composition of the present invention is intended to form a coating film having a dry film thickness of 100 μm or more by a single coating at room temperature, and the use of scaly pigments that can reduce the internal stress of the coating film is extremely It is effective for. The scaly pigment may be a part or all of the pigment used in the coating composition.

In the coating composition of the present invention, when the aspect ratio of the scaly pigment is less than 1.2, it is difficult to obtain a shielding effect, while when the aspect ratio exceeds 100, the coating workability is deteriorated, In some cases, scaly pigments are not properly arranged during film formation. In the coating composition of the present invention, the aspect ratio of the scaly pigment is more preferably 20-100. In the present invention, the aspect ratio of the scaly pigment is a ratio (D / T) of 50% volume average diameter (D) and average thickness (T). In the present invention, the 50% volume average diameter refers to the 50% particle diameter (D ₅₀ ) of the volume-based particle size distribution, and is measured using a particle size distribution measuring device (for example, a laser diffraction / scattering particle size distribution measuring device). From the particle size distribution. The particle diameter of the scaly pigment is represented by a sphere equivalent diameter by a laser diffraction / scattering method. Moreover, in this invention, the thickness of the scaly pigment was measured using SEM (scanning electron microscope), and average thickness was calculated | required for 100 or more particle | grains.

  Further, in the coating composition of the present invention, the (D) pigment can contain a pigment other than the above-mentioned scaly pigment, and such a pigment is not particularly limited and is generally used in the coating industry. And coloring pigments, rust preventive pigments and extender pigments. Specific examples of color pigments, rust preventive pigments and extender pigments include titanium oxide, bengara, yellow iron oxide, carbon black, aluminum tripolyphosphate, zinc phosphate, condensed aluminum phosphate, barium metaborate, calcium carbonate, barium sulfate, Inorganic pigments such as kaolin, talc, clay, mica, alumina, alum, white clay, magnesium hydroxide, and magnesium oxide, phthalocyanine blue, phthalocyanine green, naphthol red, quinacridone red, benzimidazolone yellow, Hansa yellow, benzimidazolone Organic pigments such as orange and dioxazine violet can be mentioned. These pigments may be used alone or in combination of two or more.

  In the coating composition of the present invention, the proportion of the pigment in the coating film forming component is preferably 40 to 69% by mass, and more preferably 50 to 65% by mass. Moreover, in the coating composition of this invention, it is preferable that the ratio of the scale-like pigment in a coating-film formation component is 3-30 mass%, and it is still more preferable that it is 10-25 mass%. Here, when the ratio of the scale-like pigment in the coating film forming component exceeds 30% by mass, the coating workability may be deteriorated, and the corrosion resistance may be decreased due to the decrease in the density of the coating film.

  The coating composition of the present invention is required to contain (E) water. In the coating composition of the present invention, the water content is preferably 25 to 45% by mass, and more preferably 25 to 35% by mass. When the content of water in the coating composition of the present invention is less than 25% by mass, it may be difficult to prepare the coating, while when it exceeds 45% by mass, it is difficult to perform thick film coating. Moreover, the coating composition of this invention may also contain the organic solvent so that it may mention later. For this reason, when the coating composition of this invention contains an organic solvent, it is preferable that the total content of water and an organic solvent is 25-45 mass%, and it is still more preferable that it is 25-35 mass%. In addition, when the coating composition of this invention contains an organic solvent, water is included as a main solvent and the ratio of the water which occupies for the mixture of water and an organic solvent is 50 mass% or more.

  The coating composition of the present invention may contain an organic solvent for the purpose of accelerating the fusion between the epoxy resin and the curing agent and improving the low-temperature film formability. Examples of the organic solvent include ethylene glycol mono n-butyl ether, ethylene glycol mono i-butyl ether, ethylene glycol mono n-propyl ether, ethylene glycol mono i-propyl ether, diethylene glycol mono n-butyl ether, diethylene glycol mono i-butyl ether, diethylene glycol. Mono n-propyl ether, diethylene glycol mono i-propyl ether, propylene glycol monomethyl ether, dipropylene glycol mono n-butyl ether, dipropylene glycol mono i-butyl ether, dipropylene glycol mono n-propyl ether, dipropylene glycol mono i-propyl Ether, diethylene glycol diethyl ether, and diethylene glycol Glycol ethers such as dibutyl ether, 2,2,4-trimethyl pentanediol mono-isobutyrate, and 2,2,4-trimethyl pentanediol diisobutyrate and the like. These organic solvents may be used alone or in combination of two or more.

  The coating composition of the present invention may contain a commonly used diluent such as a reactive diluent or a non-reactive diluent for the purpose of improving the flexibility of the coating film. Examples of reactive diluents include Cardura E10 (trade name, manufactured by Yuka Shell Epoxy Co., Ltd.), Neotote S (trade name, manufactured by Toto Kasei Co., Ltd.), and Adeka Glycilol ED502 (trade name, manufactured by Asahi Denka Kogyo Co., Ltd.). Monofunctional epoxy resins such as On the other hand, examples of the non-reactive diluent include petroleum resins such as Nicanol LLL and coumarone resins. These diluents may be used alone or in combination of two or more.

  The coating composition of the present invention includes a binder resin other than an epoxy resin, an antirust agent, a dispersant, an antifoaming agent, an anti-settling agent, an antifungal agent, an antiseptic agent, an ultraviolet absorber, a light stabilizer, and a pH adjuster. Etc. may be appropriately blended as necessary. Examples of the rust inhibitor include sodium nitrite, calcium nitrite, ethylenediaminetetraacetic acid (EDTA), and propylenediaminetetraacetic acid (PDTA). In the coating composition of the present invention, the proportion of the rust inhibitor in the coating film forming component is preferably 0.01 to 2% by mass.

  The coating composition of the present invention is a two-component water-based epoxy resin coating composition in which (A) an epoxy resin and (B) a curing agent are mixed and used immediately before coating. The coating composition of the present invention is stored separately from an epoxy resin and a curing agent, and is prepared by mixing them immediately before coating. The epoxy resin is usually stored in combination with water and various components appropriately selected as necessary, and this is referred to as a main agent. Further, the curing agent is usually stored in combination with water and various components appropriately selected as necessary, and this is referred to as a curing agent mixture. In addition, in order to adjust the viscosity of the coating composition of this invention, after mixing the said main ingredient and a hardening | curing agent mixture, you may further add water.

  Next, the coated body of the present invention will be described in detail. The coated body of the present invention is a coated body including a base material and a coating film disposed on the surface of the base material, and the coating film is formed by the above-described aqueous epoxy resin coating composition of the present invention. It is characterized by that.

  Here, in the coated body of the present invention, the coating film formed by the water-based epoxy resin coating composition of the present invention preferably has a dry film thickness of 100 to 300 μm, more preferably 100 to 150 μm. . If the dry film thickness is 100 μm or more, the corrosion resistance can be further improved. In the present invention, the dry film thickness of the coating film refers to the film thickness after drying for 24 hours under the conditions of 23 ° C. and 50% relative humidity.

  As for the base material which comprises the coating body of this invention, metal base materials, such as steel, zinc, aluminum, copper, and tin, are mentioned, for example. In addition, steel or the like that has been subjected to a base treatment for the purpose of further improving the anticorrosion property can be applied, and examples of the base treatment include zinc rich paint, galvanization, and metal spraying. In addition, the base material has various shapes depending on the application, and examples thereof include a plate shape.

  The coated body of the present invention can form a multilayer coating film by applying another type of coating as a top coating film on the surface of the coating film formed by the aqueous epoxy resin coating composition of the present invention. it can.

  Specific examples of the coated body of the present invention include automobiles, trains, aircraft and other transportation equipment and members thereof, bridges and members thereof, steel towers and members thereof, civil engineering members, waterproof sheets, tanks, pipes and other industrial equipment, Examples include building exteriors, doors, window gate members, monuments, poles and other building members, road median strips, guardrails, sound barriers, traffic lights and other road members, communication equipment and members thereof, and home appliances.

  Next, the manufacturing method of the coated body of this invention is demonstrated in detail. The method for producing a coated body of the present invention is characterized in that the above-described aqueous epoxy resin coating composition of the present invention is coated on the surface of a substrate. Further, when the coated body of the present invention has a multilayer coating film, the above-described aqueous epoxy resin coating composition of the present invention is coated on the surface of the substrate (preferably, the treated surface of the above-mentioned base-treated substrate). A film can be formed and then another coating can be applied over the coating to form a multilayer coating. As a specific example, when the coated body of the present invention is provided with an undercoat film and a topcoat film, the method for producing the coated body of the present invention comprises applying the above-described aqueous epoxy resin coating composition of the present invention to the substrate surface. A base coat film is formed, and then a top coat is applied to the surface of the base coat film to form a top coat film. Moreover, when the coated body of the present invention comprises an undercoat coating film, an intermediate coating film, and a topcoat coating film, the method for producing the coated body of the present invention includes the above-described aqueous epoxy resin coating composition of the present invention on the substrate surface. Apply to form an undercoat film, then apply an intermediate coat on the surface of the undercoat to form an intermediate coat, and then apply an overcoat to the surface of the intermediate coat A top coat film is formed.

  In the method for producing a coated body of the present invention, examples of the intermediate coating include epoxy resin-based intermediate coating, modified epoxy resin-based intermediate coating, and urethane resin-based intermediate coating. Further, examples of the top coating include acrylic resin-based top coating, urethane resin-based top coating, silicone resin-based top coating, and fluororesin-based top coating.

  In the manufacturing method of the coating body of this invention, it does not restrict | limit in particular, A known coating means, for example, air spray coating, airless spray coating, brush coating, or roller coating etc. can be utilized. The drying temperature of the coating composition is preferably 5 to 35 ° C. Furthermore, the drying time of the coating composition is preferably 2 to 24 hours, more preferably 2 to 16 hours, for example, at 23 ° C. and 50% relative humidity. In addition, when applying the coating composition of the next process in order to form a laminated coating film, for example, at 23 ° C. and 50% relative humidity, the coating can be applied without any trouble if it is dried for 4 hours to 10 days. Furthermore, from the viewpoint of repair, when the aqueous epoxy resin coating composition of the present invention is coated on a substrate, there is a coating film (old coating film) already covering the substrate to be coated. There is also.

  Next, the anticorrosion coating method of the present invention will be described in detail. The anticorrosion coating method of the present invention is characterized in that the above-described aqueous epoxy resin coating composition of the present invention is coated on the surface of a substrate.

  Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to the following examples.

<Preparation example of main agent>
According to the formulation shown in Tables 1 and 2, raw materials were mixed to prepare main agents 1 to 18.

The compounding agents shown in Tables 1 and 2 are as follows.
(* 1) Disperbyk-190, manufactured by Big Chemie Japan (active ingredient 100% by mass)
(* 2) BYK-093, manufactured by Big Chemie Japan, Inc. (active ingredient 98% by mass or more)
(* 3) Titanium oxide, 50% volume average diameter 0.3 μm
(* 4) Aluminum tripolyphosphate, 50% volume average diameter 3.5 μm
(* 5) Precipitated barium sulfate, 50% volume average diameter 1.0 μm
(* 6) Mica, manufactured by Cyberco Japan, shape: scale, 50% volume average diameter 25 μm, aspect ratio 50
(* 7) Kaolin, manufactured by Sanyo Clay, shape: scale, 50% volume average diameter 5 μm, aspect ratio 1.3
(* 8) Mica, manufactured by Yamaguchi Mica, shape: scaly, 50% volume average diameter 47 μm, aspect ratio 80
(* 9) Adeka Resin EM-101-50 (Aqueous dispersion of bisphenol A type epoxy resin), manufactured by Adeka, solid content 47% by mass, epoxy equivalent 510 g / eq (solid content)
(* 10) Beckpox EP2381 (Aqueous dispersion of bisphenol A type epoxy resin), manufactured by Ornex, solid content 55% by mass, epoxy equivalent 500 g / eq (solid content)
(* 11) Epochon EA55, Japan NSC, 55 mass% solid content, epoxy equivalent 495 g / eq (solid content)
(* 12) jER W3435R67 (Aqueous dispersion of bisphenol A epoxy resin), manufactured by Mitsubishi Chemical Corporation, solid content 67% by mass, epoxy equivalent 273 g / eq (solid content)
(* 13) Propylene glycol monomethyl ether (* 14) Sodium nitrite (* 18) Thixol W-502, Kyoeisha, water dispersion of polyacrylic acid viscosity modifier, viscosity modifier content: 21% by mass

<Preparation example of curing agent mixture>
According to the formulation shown in Tables 3-4, the raw materials were mixed to prepare hardener mixtures 1-13.

The compounding agents shown in Tables 3 to 4 are as follows.
(* 15) Fujicure FXS-918-FA, manufactured by T & K TOKA, an aqueous dispersion of a modified polyamine compound of an epoxy adduct type in which an epoxy group is added to an amino group, a solid content of 60% by mass
(* 16) EK8545-W52, manufactured by Momentive, an aqueous dispersion of a modified polyamidoamine obtained by amidating the amino group of polyamine, solid content 52% by mass
(* 17) Disparon AQ-001, manufactured by Enomoto Kasei Co., Ltd., polyacrylic acid viscosity modifier aqueous dispersion, viscosity modifier content: 15% by mass
(* 18) Thixol W-502, Kyoeisha, polyacrylic acid viscosity modifier aqueous dispersion, viscosity modifier content: 21% by mass
(* 19) ASA ER-3, manufactured by Ito Oil Co., Ltd., polyurethane-based viscosity modifier aqueous dispersion, viscosity modifier content: 20% by mass
(* 20) BYK-420, manufactured by BYK, polyurethane-based viscosity modifier aqueous dispersion, viscosity modifier content: 52% by mass
(* 21) Thixol W-400LP, manufactured by Kyoeisha, water dispersion of a mixture of fatty acid polyamide and oxidized polyethylene, viscosity modifier content: 25% by mass
(* 22) NATROSOL 250HR, manufactured by Ashland, cellulose-based viscosity modifier, manufactured by Ashland, viscosity modifier content: 100% by mass
(* 23) Sodium caseinate, protein thickener, viscosity modifier content: 100% by mass
(* 24) OPTIGEL WM, manufactured by Rockwood, clay mineral (montmorillonite), viscosity modifier content: 100% by mass

<Preparation example of coating composition>
According to the formulation shown in Tables 5-8, the main agent and the curing agent mixture are mixed to prepare coating compositions 1-28, and the viscosity, sagging property, coating workability, anticorrosiveness and adhesion of the coating composition are measured. And evaluated. The results are shown in Tables 5-8.

<Viscosity measurement>
About the coating composition at 23 degreeC, the viscosity in shear rate 0.1 (1 / s) and the viscosity in shear rate 1000 (1 / s) were measured using the rheometer ARES by TA Instruments.

<Coating workability>
The paint composition was applied to the tin plate by brush coating and roller coating once so that the thickness was 100 μm, and the coating workability was evaluated according to the following criteria. The coated film was dried for 24 hours under conditions of 23 ° C. and 50% relative humidity. The dry film thickness was measured using an electromagnetic film thickness meter SM-1000 manufactured by Sanko Electronic Laboratory.
A: The coating composition spreads uniformly, the finish of the coated surface is good, and a dry film thickness of 100 μm can be obtained by a single application.
(Triangle | delta): Although a coating composition spreads uniformly and some unevenness | corrugations are recognized on the surface, a dry film thickness of 100 micrometers is obtained by one application.
X: Regardless of the coating method, it is difficult to apply a dry film thickness of 100 μm in a single application, or unevenness on the surface of the coating film is remarkable, and abnormal appearance is recognized.

<Sagging test>
A water-based epoxy resin coating composition was applied to a tin plate installed on a vertical surface by brushing so that the theoretical dry film thickness was 100 μm, and the sag of the formed coating film was evaluated according to the following criteria. .
○: The flow (sag) of the paint is not recognized.
X: The flow (sag) of the paint is recognized and abnormal appearance is observed.

<Anti-corrosion>
A grid blasted steel plate (150 × 70 × 3.2 mm) having a base adjustment degree of ISO 8501-1 Sa2.5 is used as a test plate, and an air spray is used on both sides of the test plate, and a dry film thickness is 100 to 100%. The coating composition was applied so as to have a thickness of 130 μm, and was dried for 7 days under the conditions of 23 ° C. and 50% relative humidity to prepare a test piece. In accordance with JIS K5600-7-9, the degree of rust and swelling generated on the test piece after 120 cycles of the test piece under the cycle D test conditions of Appendix 1 was evaluated according to the following criteria.
○: There is no abnormality such as rust and swelling on the surface of the test piece 2 mm or more away from the cut part.
Δ: Rust and swelling are generated on the surface of the test piece 2 mm or more and less than 4 mm away from the cut part, but there is no abnormality such as rust or swelling on the test piece surface 4 mm or more away from the cut part.
X: Rust and swelling occur on the surface of the test piece 4 mm or more away from the cut part.

<Adhesiveness>
A test piece was prepared in the same manner as in the evaluation of the anticorrosion property. The test piece was subjected to an adhesion test according to JIS K 5600-5-7 (pull-off method) and evaluated according to the following criteria.
○: Adhesion strength 4 MPa or more Δ: Adhesion strength 2 MPa or more and less than 4 MPa ×: Adhesion strength 2 MPa or less

Claims (8)

  (A) An epoxy resin, (B) a curing agent, (C) a viscosity modifier, (D) a pigment, and (E) at least water, and (A) an epoxy resin and (B) a curing agent are mixed immediately before coating. A two-component water-based epoxy resin coating composition used, wherein the content of the film-forming component in the water-based epoxy resin coating composition is 55 to 75% by mass, and (C) viscosity The water-based epoxy resin coating composition, wherein the adjusting agent is at least one selected from the group consisting of a polyacrylic acid viscosity adjusting agent and a polyurethane viscosity adjusting agent.   The viscosity at a shear rate of 0.1 (1 / s) is 50 to 500 (Pa · s, 23 ° C.), and the viscosity at a shear rate of 1000 (1 / s) is 0.01 to 1 (Pa · s, 23 ° C.). The water-based epoxy resin coating composition according to claim 1, wherein   The pigment (D) contains at least one scaly pigment having an aspect ratio of 1.2 to 100 selected from the group consisting of talc, mica, kaolin clay, glass flakes, and mica-like iron oxide, The water-based epoxy resin coating composition according to claim 1, wherein the ratio of the scaly pigment in the film-forming component is 3 to 30% by mass.   The water-based epoxy resin coating composition according to claim 3, wherein the scale-like pigment has an aspect ratio of 20 to 100. A coated body comprising a substrate and a coating film disposed on the surface of the substrate,
The said coating film is formed with the water-system epoxy resin coating composition of any one of Claims 1-4, The coating body characterized by the above-mentioned.   The manufacturing method of the coating body characterized by coating the base-material surface with the water-system epoxy resin coating composition of any one of Claims 1-4.   The base epoxy film is formed by coating the water-based epoxy resin coating composition according to any one of claims 1 to 4 on a substrate surface, and then a top coating is applied to the surface of the base coating film. The manufacturing method of the coating body characterized by forming a coating film.   A base epoxy coating is formed by coating the water-based epoxy resin coating composition according to any one of claims 1 to 4 on a substrate surface, and then an intermediate coating is applied to the surface of the primer coating. A method for producing a coated body, wherein an intermediate coating film is formed, and then a top coating film is formed on the surface of the intermediate coating film to form a top coating film.