JP6514850B2 - Water-based anticorrosion coated metal products - Google Patents

Description

The present invention relates to aqueous anti-rust coated metal products rust metal products subjected to proof instrument water Seibosabi paint.

  Machine tools, transport machines, these parts, steel pipes, steel bars, construction materials such as steel frames, stairs, handrails, and other metal products have been used for the purpose of preventing rust and protecting the final materials before they become final products. A treatment has been applied to the surface. The metal products are often manufactured from iron-based metal materials for reasons such as cost of raw materials, strength, ease of processing, etc., and are left as they are from manufacture to actual use. Also, the surface is oxidized by moisture in the air, corrosive substances, etc., and rust occurs. For this reason, in order to prevent the occurrence of rust in advance and maintain the quality of the metal product, it is general to perform processing immediately after the production of the material for the product.

  Among the metal products, machine tool parts such as press dies whose surface condition affects processing, metal components such as metal fittings whose surface condition affects strength, reinforcing bars embedded in concrete, steel frames, anchor bolts, etc. In construction materials, rust-proof coating is often performed on final products as a treatment for surface protection.

  Since many paints conventionally used contain volatile organic solvents, it is necessary to take measures against volatile organic compounds (VOCs) for workers and the surrounding environment before use. Moreover, since the paint used conventionally contains an organic solvent, it is necessary to pay sufficient attention to management of storage amount, storage place, etc. even when storing. Therefore, a water-based paint containing as little organic solvent as possible is required.

As an aqueous paint for the purpose of protecting the surface of a metal product, for example, a synthetic resin emulsion as described in Patent Document 1 is used as a film-forming component, and a metal salt or amine salt of dinonyl naphthalene sulfonic acid as a rust inhibitor Aqueous anticorrosion paints are known to be contained.
Further, as a metal product painted for the purpose of protecting the surface of a metal product, for example, a concrete-embedded rebar member having an anticorrosion coating with an epoxy powder coating as described in Patent Document 2 is known.

JP, 2011-57942, A Patent No. 4319995

  The metal product to be protected is not always shipped immediately after manufacture, is stored until shipment, and may be delivered or stored to the purchaser, and may not be used immediately. Furthermore, in the case of construction materials such as reinforcing bars and steel frames embedded in concrete classified as metal products, the coating film should not prevent adhesion of the reinforcing bars, steel frames, etc. to concrete. And there are many cases where the construction work of the next process is awaited in a state where a part of the construction material buried is exposed. If the construction period is extended or extended, or if construction is suspended, the construction materials remain intact and the environment changes significantly, such as in a hot and humid environment in summer and a low-temperature dry environment in winter. It may be stored and left untouched.

  However, although the water-based anti-corrosive paint described in Patent Document 1 has anti-corrosion performance, it takes into consideration the rust that occurs between the application of the paint and the time when the water-based anti-corrosion paint becomes a dry film. The film thickness after drying is also considered to be 50 to 1000 μm (see, for example, paragraph 0036). Therefore, the water-based rustproofing coating described in Patent Document 1 having a thick coating is not a coating considering the formability of a thin film coating and the adhesion performance of a coated metal product to concrete.

  The paint described in Patent Document 2 has an anticorrosion performance, and the coated metal product also has an adhesion performance to concrete, but it is necessary to apply and bake a plurality of paints with paints having different components. Also, as in the case of the aqueous rust-preventive paint described in Patent Document 1, the film thickness is considered to be 200 to 400 μm (see paragraphs 0028 and 0029), and the formability of the thin film is considered. It is not a paint.

The present invention has been made in view of the above problems, concrete and excellent adhesion performance, excellent long-term anticorrosive performance is possible to correspond to changes in the environment after painting painted with thin aqueous the challenge is to provide the anti-rust coated metal product.

That is, the metal product according to the present invention provides an aqueous anti-rust coated metal product, which is embedded in the concrete which has been subjected to water Seibosabi paint, said aqueous anticorrosive paint, and epoxy resin emulsion, a water-soluble acrylic resin A proportion of the amount of epoxy resin constituting the epoxy resin emulsion with respect to the total amount of the resin constituting the epoxy resin emulsion and the water-soluble acrylic resin, containing an aqueous rust inhibitor and an aqueous wetting agent is 30% by mass or more The ratio of the total amount of the resin constituting the epoxy resin emulsion and the water-soluble acrylic resin to the aqueous anti-corrosive paint is 10% by mass to 40% by mass, and the aqueous anti-corrosive agent of the aqueous anti-rust agent The proportion to the paint is 0.1% by mass to 5% by mass, and the proportion of the aqueous wetting agent to the aqueous anticorrosion paint is 0.1% by mass or more A less by mass%, the glass transition point of the water-soluble acrylic resin is at 125 ° C. or less 0 ℃ or higher, and an acid value of the water-soluble acrylic resin is not more than 80 mg / KOH or 240 mg / KOH, the aqueous It is characterized in that the film thickness after drying of the water-based anticorrosion paint on the surface of the anticorrosion coated metal product is 3 μm or more and 20 μm or less. Preferably, the aqueous wetting agent of the metal product according to the present invention is a polyether-modified silicone-based aqueous wetting agent.

According to the composition of such a coating, the epoxy resin maintains the strength of the coating film, and the acrylic resin maintains the flexibility of the coating film, so that deformation of the object to be coated, temperature change, humidity change, etc. after coating It becomes an aqueous anticorrosion paint which can form a thin film which can cope with the environmental change of Moreover, according to the structure of such a coating material, the surface tension of the coating material is reduced to provide an aqueous anticorrosive coating material that is easy to coat. Furthermore, it becomes an aqueous anticorrosion paint which can form a coating film with good adhesion performance with concrete. In addition, according to the polyether modified silicone type aqueous | water-based wetting agent, a modified epoxy resin and a water-soluble acrylic resin form a more uniform and tough coating film by the surface tension of a coating film falling more. At the same time, good adhesion between the coating and the concrete is also maintained.
According to the configuration of such a metal product, the adhesion of the substance causing the rust of the metal product such as water on the surface of the object to be coated is prevented, and the substance causing the rust from the surface of the object to be coated is efficiently blocked. It is possible to In addition, the strength of the coating film excellent in corrosion resistance containing a modified epoxy resin, and the amount of low molecular components in the coating film after drying which affects the adhesion performance are controlled to prevent corrosion and coating film. It is possible to properly maintain the adhesion performance between aluminum and concrete.

The aqueous rustproof coated metal product of the present invention is excellent in adhesion performance to concrete, can cope with environmental changes after painting, and can provide an effect of excellent long-term rustproof performance.

  Next, the composition of the aqueous anticorrosive paint according to the present invention and the metal product coated with the aqueous anticorrosive paint will be described in detail.

<Water-based anticorrosion paint>
As will be described below, the aqueous anti-corrosive paint according to the present invention comprises an epoxy resin emulsion, a water-soluble acrylic resin, an aqueous anti-rust agent, and an aqueous wetting agent.
Each component will be described below.

(Epoxy resin emulsion)
The epoxy resin emulsion, together with the water-soluble acrylic resin, dries and hardens to prevent the corrosion-causing substance of metal products including construction materials such as reinforcing bars from adhering to the surface of metal products, and the corrosion-causing substances from the metal product surface A coating film to be blocked is formed on the surface of a metal product. By containing the epoxy resin, the aqueous anti-corrosive paint improves the strength of the coating, and more effectively and effectively blocks corrosion-causing substances such as water from the surface of the metal product as compared with the case where the epoxy resin is not contained. For this reason, even if the coating film thickness is a thin film thickness of 3 to 20 μm, the anticorrosion performance lasts for at least 12 months.
The epoxy resin emulsion is an emulsion obtained by forcibly stirring an epoxy resin in water using an emulsifier, an emulsion obtained by forcibly stirring a modified epoxy resin in water, or forced stirring in water of a modified epoxy resin using an emulsifier. It is an emulsion in which an epoxy resin is dispersed in an aqueous solvent, such as an emulsified emulsion.

The epoxy resin which comprises an epoxy resin emulsion is a main component of a coating material and an epoxy resin emulsion, for example, the reaction product (modified epoxy resin) of an epoxy resin and a fatty acid can be mentioned. The epoxy resin constituting the epoxy resin emulsion is, for example, an epoxy resin, and one or two kinds of (meth) acrylic acid, (meth) acrylic acid alkyl ester, (meth) acrylic acid hydroxyalkyl ester, and styrene. The reaction product with the polymer containing the above can be mentioned. Furthermore, the epoxy resin constituting the epoxy resin emulsion is, for example, one of (meth) acrylic acid, (meth) acrylic acid alkyl ester, (meth) acrylic acid hydroxyalkyl ester, styrene, or the like in the presence of the epoxy resin. The reaction product in which 2 or more types were made to react can be mentioned. The epoxy resin constituting the epoxy resin emulsion may be, for example, a reaction product of an epoxy resin and a polyoxyalkylene amine compound. Among these, (meth) acrylic acid, (meth) acrylic acid alkyl ester, (meth) acrylic acid hydroxyalkyl ester, a reaction product obtained by reacting one or more kinds of styrene in the presence of an epoxy resin It is practical.
The epoxy resin constituting the epoxy resin emulsion does not have to be modified as long as it can be dispersed in an aqueous solvent, and is not particularly limited thereto.

The epoxy resin constituting the epoxy resin emulsion is preferably a bisphenol A epoxy resin, a bisphenol F epoxy resin, or a bisphenol AD epoxy resin, and a resin having an epoxy equivalent in the range of about 150 to about 1000 is preferable. Specifically, jER 807, 828, 834, 1001, 1004 (manufactured by Mitsubishi Chemical Corporation), YSLV-80XY (manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.), DER 331, 383 (manufactured by Dow Chemical Company), Epicoat 828, 834, 1001, 1004 (manufactured by Yuka Shell Epoxy Co., Ltd.) and the like can be mentioned.
In addition, the epoxy resin which comprises an epoxy resin emulsion is not restricted to a bisphenol type epoxy resin, as long as it can disperse | distribute to an aqueous solvent, There is no restriction | limiting in the kind of epoxy resin.

(Water soluble acrylic resin)
The water-soluble acrylic resin dries and hardens to prevent adhesion of corrosion-causing substances of metal products such as reinforcing bars to the surface of metal products together with epoxy resin constituting the epoxy resin emulsion, modified epoxy resin, etc. To form a coating on the surface of the metal product to block it from the surface of the metal product.

  The water-soluble acrylic resin not only dries and cures to form a coating on the surface of the object to be coated, thereby blocking corrosion causing substances but also imparts flexibility to the coating. When the water-based anti-corrosive paint contains a water-soluble acrylic resin, the coating film formed on the surface of the object to be coated follows the deformation of the object to be coated due to thermal expansion, thermal contraction, etc. Anti-corrosion performance is maintained for a long time while preventing damage such as peeling.

The water-soluble acrylic resin includes not only a water-soluble acrylic resin but also a water-soluble acrylic resin. The water-soluble acrylic resin of the present invention is, for example, a simple selected from (meth) acrylic acid, itaconic acid, fumaric acid, crotonic acid, citraconic acid, vinylsulfonic acid and (meth) allylsulfonic acid. 1 type of a monomer, or 2 or more types, (meth) acrylic acid alkyl esters, (meth) acrylic acid hydroxyalkyl esters, and 1 type of a monomer arbitrarily selected from styrene Or the polymer with 2 or more types can be mentioned. Among these, (meth) acrylic acid, methyl methacrylate, butyl (meth) acrylate, hydroxyethyl methacrylate and styrene are practical.
In addition, as long as it is the water-soluble acrylic resin monomer which has a reactive double bond, it does not specifically limit to these.

(Epoxy resin content rate)
The epoxy resin content relative to the total amount of the resin and the water-soluble acrylic resin constituting the epoxy resin emulsion constituting the aqueous anticorrosive coating, that is, the epoxy resin content, which is the epoxy resin content relative to the total resin component amount, Affects rust performance.
The amount of epoxy resin is 30% by mass or more based on the total amount of the resin constituting the epoxy resin emulsion and the water-soluble acrylic resin. If the epoxy resin content is less than 30% by mass, the amount of epoxy resin in the paint and in all the resin components is small, and therefore, the anticorrosion performance can not be obtained by containing the epoxy resin.
The higher the content of the epoxy resin, the higher the rust prevention performance, and thus there is no particular limitation. The upper limit of the content of the epoxy resin may be in a range that satisfies the upper limit of the amount of resin component described later.

(Amount of resin component)
The amount of resin component in the aqueous anticorrosive paint, that is, the total content of the resin and the water-soluble acrylic resin constituting the epoxy resin emulsion in the aqueous anticorrosive paint affects the film forming performance of the paint and the ease of handling of the paint. give.
The ratio of the total amount (resin component) of the resin and the water-soluble acrylic resin constituting the epoxy resin emulsion is 10% by mass or more and 40% by mass or less based on 100% by mass of the entire aqueous rustproofing paint.

If the ratio of the total amount of the resin and the water-soluble acrylic resin constituting the epoxy resin emulsion is less than 10% by mass, the coating film-forming component in the coating is small and the coating thickness becomes thin when coated and the strength of the coating is increased. By reducing the thickness, damage such as cracking or peeling of the coating film is likely to occur. In addition, since the thickness of the coating film becomes uneven and the strength of the coating film is different, damage such as cracking or peeling of the coating film tends to occur. For this reason, the moisture and the like that are the causative agents of corrosion can easily reach the surface of the metal product to be coated through cracking and peeling of the coating film, and the anticorrosion performance required as an anticorrosion paint can not be obtained. In addition, there is a possibility that the resin component is too small to be realized as a paint.
On the other hand, when the proportion of the total amount of the resin and the water-soluble acrylic resin constituting the epoxy resin emulsion exceeds 40% by mass, the viscosity of the aqueous anticorrosive coating becomes high. For this reason, when the ratio of the resin component amount in the aqueous anticorrosive coating exceeds 40% by mass, it is difficult to form a uniform thin film as a thin film, which is not preferable because the aqueous anticorrosive coating becomes inconvenient. In addition, there is a possibility that gelation does not occur as a paint.

(Glass transition point of water-soluble acrylic resin)
The glass transition point (Tg) of the water-soluble acrylic resin is 0 ° C. or more and 125 ° C. or less. When the glass transition point is less than 0 ° C., the coating after drying of the aqueous anticorrosion paint becomes soft and the coating strength decreases. For this reason, damage such as cracking or peeling of the coating film occurs starting from the portion where the coating film strength is reduced, and the causative substance of the corrosion infiltrates, thereby preventing the aqueous anticorrosion paint against the metal product to be coated. Rust performance is reduced. When the glass transition temperature exceeds 125 ° C., the coating after drying of the aqueous anticorrosion paint becomes hard, and the flexibility of the coating decreases. For this reason, it is not possible to follow the deformation due to the thermal expansion, thermal contraction, etc. of the object to be coated, and damage such as cracking or peeling of the coating film occurs to cause the corrosion causing substance to infiltrate. The anticorrosion performance of the aqueous anticorrosion paint to metal products is reduced.
The lower limit value of the glass transition point of the more preferable water-soluble acrylic resin is 10 ° C. or more.
The upper limit value of the glass transition point of the more preferable water-soluble acrylic resin is 115 ° C. or less.

The glass transition point of the water-soluble acrylic resin can be measured by measuring a measurement sample with a differential scanning calorimeter according to the definition of JIS K7121.
In addition, a reaction sample containing a water-soluble acrylic resin after synthesis of a water-soluble acrylic resin described later is heated and dried at 105 ° C. for 1 hour according to JIS K 5601-1 to obtain a measurement sample. Next, the glass transition point of the water-soluble acrylic resin can also be measured by measuring the obtained measurement sample with a differential scanning calorimeter according to the definition of JIS K7121.
The glass transition point (Tg) can be adjusted to be within the range of the present invention by adjusting the composition, polymerization degree and the like of the water-soluble acrylic resin.

(Acid value of water-soluble acrylic resin)
The acid value of the water-soluble acrylic resin makes it easy to dissolve the resin component of the water-based anti-corrosion paint in a solvent such as water, and a paint film having anti-corrosion performance on the surface of the metal product which is the object to be coated Are defined to facilitate uniform formation of thin films.

The acid value of the water-soluble acrylic resin is 80 mg / KOH or more and 240 mg / KOH or less. When the acid value is less than 80 mg / KOH, the film forming performance of the paint is reduced because the water-soluble acrylic resin has low hydrophilicity. For this reason, the thickness of the coating film becomes uneven, and the strength of the coating film becomes uneven. Then, damage such as cracking or peeling of the coating film occurs starting from the portion where the coating film strength is reduced, and the substance causing the corrosion enters, whereby the antirust performance is reduced. When the acid value exceeds 240 mg / KOH, the wettability of the coating after drying becomes high, so that moisture and the like due to rain water, condensation and the like can be easily taken into the coating. For this reason, the water | moisture content etc. which are a causative substance of corrosion become easy to reach the surface of a metal product, and rustproof performance falls.
The lower limit value of the acid value of the more preferable water-soluble acrylic resin is 100 mg / KOH or more.
The upper limit of the acid value of the water-soluble acrylic resin is more preferably 220 mg / KOH or less.

The acid value of the water-soluble acrylic resin can be obtained by diluting the water-soluble acrylic resin with a mixed solvent of toluene: ethanol = 2: 1 in volume ratio and measuring according to the definition of JIS K 560-1-2 is there.
In addition, a reaction solution containing a water-soluble acrylic resin after synthesis of a water-soluble acrylic resin described later is diluted with a mixed solvent of toluene: ethanol = 2: 1 in volume ratio, and measured according to the definition of JIS K5601-2-1. The acid value of the water-soluble acrylic resin can also be measured.
It is preferable to adjust the composition, the degree of polymerization, and the like of the water-soluble acrylic resin so that the acid value measured in this manner falls within the range of the present invention.

(Water-based rust inhibitor)
The aqueous anti-rust agent is a component that improves the anti-corrosion performance of the aqueous anti-corrosion paint in coexistence with the resin that constitutes the epoxy resin emulsion in the coating film and the water-soluble acrylic resin. The aqueous rustproofing agent is preferably one that continuously improves the adhesion performance between a concrete and a construction material such as a reinforcing bar which is an object to be coated. For this reason, it is easy to mix with a water-soluble acrylic resin, and an aqueous antirust agent having high affinity to concrete is used.

The aqueous anti-rust agent is not limited as long as it is aqueous (water-soluble), but it preferably comprises an organic acid and a base.
Examples of the organic acid include carboxylic acids such as octanoic acid, oleic acid, dimer acid and naphthenic acid, sulfonic acids such as alkylbenzene sulfonic acid and alkyl naphthalene sulfonic acid, and alkyl phosphoric acids. Examples of alkyl naphthalene sulfonic acids include dinolyl naphthalene sulfonic acid.
Examples of the base include water-soluble amines such as ammonia, ethanolamine, diethanolamine, triethanolamine, dimethylethanolamine, diethylethanolamine and the like.

  The aqueous antirust agent preferably used is obtained by selecting and combining one kind of each of the organic acid and the base. Furthermore, one or more types selected from among these organic acids and two or more types arbitrarily selected from among these bases, or two or more types arbitrarily selected from among these organic acids and any from among these bases It may be a mixture in combination with one selected from. And the mixture by the combination of these two or more types of organic acids and these two or more types of bases may be sufficient. Particularly preferred combinations are combinations of alkyl naphthalene sulfonic acid, carboxylic acid and diethanolamine.

(Content of aqueous rust inhibitor)
The content rate of the aqueous antirust agent is 0.1% by mass or more and 5% by mass or less when the total amount of the aqueous anticorrosive coating is 100% by mass. If the addition ratio of the aqueous rust inhibitor is less than 0.1% by mass, the performance of the rust inhibitor is not sufficiently exhibited, so that the rust prevention performance of the aqueous rust preventive paint is deteriorated. Also, if the addition ratio of the aqueous rust inhibitor exceeds 5% by mass, the aqueous rust inhibitor also acts as a surfactant, so the lubricity of the coated film surface after drying increases and the coated film after drying Contact resistance with concrete decreases. Therefore, the adhesion performance of a coating film and concrete will fall, when the addition rate of an aqueous | water-based rustproofing agent exceeds 5 mass%.
The content of the aqueous wetting agent is preferably calculated based on the amount of non-volatile component described later.

(Aqueous wetting agent)
The aqueous wetting agent is a component for improving the film forming performance of the paint and for uniformly forming a coating film having an antirust performance on a metal product surface with a thin film.
The aqueous wetting agent should have an affinity for the epoxy resin emulsion forming the coating and the water-soluble acrylic resin to be mixed therewith. A water-based wetting agent reduces the surface tension of the water-based anti-corrosion paint to more effectively exhibit the anti-corrosion performance of the water-based anti-corrosion paint according to the present invention to reduce the surface tension of the water-based anti-corrosion paint. Those which improve the wettability to the product (wettability, wetting properties) are preferred. Further, it is preferable that the aqueous wetting agent continuously improve the adhesion performance of the aqueous anticorrosion coating with concrete.
For this reason, the wetting agent is an aqueous wetting agent that is hydrophilic.

The aqueous wetting agent may be of any type as long as it is aqueous (water soluble). For example, acrylic resin-based aqueous wetting agents, fluorine-modified polymer-based aqueous wetting agents, and silicone-based aqueous wetting agents can be mentioned. Among the aqueous wetting agents, polyether-modified silicone-based aqueous wetting agents are preferred.
The polyether-modified silicone-based aqueous wetting agent is preferable because the degree of decrease in surface tension of the coating is large, and the modified epoxy resin and the water-soluble acrylic resin can form a more uniform and tough coating. At the same time, it is preferable because good adhesion performance between the coating and the concrete can be easily maintained.

  Specific examples of commercially available aqueous wetting agents that can be used as the aqueous wetting agent according to the present invention include BYK 345 manufactured by Byk Chemie Japan Co., Ltd. as a polyether modified polydimethylsiloxane which is a polyether modified silicone based aqueous wetting agent. Examples of ether-modified siloxanes include BYK 349 manufactured by BYK-Chemie Japan Co., Ltd., and examples of polyether-modified polydimethylsiloxanes include DISPARLON LS-480 manufactured by Kushimoto Chemicals Co., Ltd.

(Content of aqueous wetting agent)
The content rate of the aqueous wetting agent is 0.1% by mass or more and 5% by mass or less when the total amount of the aqueous anticorrosion coating is 100% by mass. If the addition ratio of the aqueous wetting agent is less than 0.1% by mass, the wettability of the aqueous anticorrosive coating decreases and the coating film becomes uneven, so that the coating film has a difference in strength and the coating film strength is reduced. It becomes easy to generate damage, such as a crack of a coating film and exfoliation, starting from a portion. Then, the moisture, which is the causative substance of corrosion, penetrates from the damaged portion to the surface of the metal product, thereby reducing the anticorrosion performance of the aqueous anticorrosion paint. Also, when the addition ratio of the aqueous wetting agent exceeds 5% by mass, the lubricity of the coated film surface after drying increases and the contact resistance between the coated film after drying and the concrete decreases, so the adhesion performance with concrete Decreases.
The content of the aqueous wetting agent is preferably calculated based on the amount of non-volatile component described later.

(Reaction solvent)
The reaction solvent is a solvent used to modify an epoxy resin to synthesize a modified epoxy resin. As the reaction solvent, an epoxy resin, a compound such as a resin used for modification, and a solvent in which a polymerization initiator is dissolved are used. The reaction solvent is preferably, for example, a solvent in which a fatty acid, an acrylic resin monomer (monomer), a polyoxyalkylene amine compound, an epoxy resin, and a polymerization initiator are dissolved.
It is more preferable that the reaction solvent is, in addition, a solvent which is uniformly mixed with water at an arbitrary ratio, which enables preparation of an epoxy resin emulsion without isolation of the modified epoxy resin after synthesis of the modified epoxy resin. As a reaction solvent which satisfy | fills these conditions, ethylene glycol monobutyl ether is mentioned, for example.

(Polymerization solvent)
The polymerization solvent is a solvent used to synthesize a water-soluble acrylic resin (polymer, polymer) by polymerizing a water-soluble acrylic resin monomer (monomer). As the polymerization solvent, one in which a water-soluble acrylic resin monomer (monomer), a water-soluble acrylic resin (polymer, polymer), and a polymerization initiator are dissolved is used.
The polymerization solvent is optionally added with water after the synthesis of the water-soluble acrylic resin, without isolation of the water-soluble acrylic resin, in the state of a solution (reaction solution) containing the water-soluble acrylic resin, the production of an aqueous anticorrosive paint becomes possible. It is more preferable if the solvent is uniformly mixed at a ratio of As a polymerization solvent which satisfy | fills these conditions, ethylene glycol monobutyl ether is mentioned, for example. The reaction solvent and the polymerization solvent may be the same type of solvent if they satisfy the conditions.

(Polymerization initiator)
The polymerization initiator is used to polymerize the water-soluble acrylic resin monomer (monomer) to polymerize the water-soluble acrylic resin (polymer, polymer). The polymerization initiator can be appropriately selected from the water-soluble acrylic resin monomer to be used, the polymerization solvent, the molecular weight of the water-soluble acrylic resin to be targeted, the degree of polymerization, etc. There is no limit. For example, t-butyl peroxybenzoate is mentioned as a polymerization initiator.

(Dilution solvent)
The dilution solvent is a solvent for adding to the reaction solution of the modified epoxy resin to form an epoxy resin emulsion. The dilution solvent is a solvent added to the reaction solution of the polymerized water-soluble acrylic resin to form a water-soluble acrylic resin solution.
In order to prevent solidification of the epoxy resin emulsion and the water-soluble acrylic resin, the dilution solvent is preferably made basic by adding a predetermined amount of water-soluble amines as a main component of water. Examples of water-soluble amines that can be added include triethanolamine, diethanolamine, triethylamine, dimethylethanolamine, aqueous ammonia and the like. The addition amount of water-soluble amines and the pH can be appropriately adjusted in accordance with the acid value of the modified epoxy resin and the water-soluble acrylic resin.

(Organic solvent)
In order to adjust the concentration and physical properties of the aqueous anticorrosion paint according to the present invention, it is also possible to add an organic solvent which is uniformly mixed with water at an arbitrary ratio.
Examples of miscible organic solvents include alcohols such as 2-butoxyethanol, 3-methoxy-3-methyl-1-butanol, 2-propanol, and propylene glycol monopropyl ether, ethylene glycol monobutyl ether, propylene glycol Ethers such as monobutyl ether can be mentioned.

(Other paint ingredients)
The aqueous anticorrosion paint according to the present invention is a range not exceeding the anticorrosion performance and the adhesion performance when the entire aqueous anticorrosion paint is 100% by mass, in a range of more than 0% by mass and 30% by mass or less It is also possible to contain other paint components.
Examples of other paint components include foam inhibitors (defoamers), thickeners, viscoelastic modifiers, extender pigments, inorganic color pigments, organic color pigments and the like. Specific examples of the extender pigment include calcium carbonate and talc, and specific examples of the inorganic coloring pigment include titanium oxide, carbon black and bengala.

(Nonvolatile component)
It is also possible to calculate the amount of each component contained in the aqueous anticorrosion paint according to the present invention from the ratio of non-volatile components. The non-volatile component ratio can be calculated, for example, from the non-volatile component amount obtained by heating at 105 ° C. specified in JIS K 5601-1-2 for 1 hour.

In the production of aqueous rustproof paint, after each paint component such as epoxy resin emulsion and water-soluble acrylic resin is synthesized, it is better to handle each paint component as it is in solution without isolating each paint component from the reaction solution. In many cases, it is convenient for the manufacturing process. Even in such a case, it is possible to calculate the content of each paint component and to manufacture the aqueous anticorrosion paint according to the present invention by using the calculation result of the non-volatile component ratio.
Examples of the computable components include an epoxy resin constituting an epoxy resin emulsion, a water-soluble acrylic resin, an aqueous rust inhibitor, an aqueous wetting agent and the like.

(viscosity)
The viscosity of the epoxy resin emulsion synthesized, and the viscosity of the water-soluble acrylic resin solution obtained by diluting the reaction solution of the water-soluble acrylic resin with a dilution solvent, etc., was measured using a Brookfield viscometer (DV-1 Prime Viscometer, Brookfield engineering Laboratorics). It can be obtained by measurement at 25 ° C. in accordance with the provisions of JIS Z8803 (2011).
The viscosity of the aqueous anticorrosive coating is preferably 20 mPa · s or more and 200 mPa · s or less in terms of film forming performance and handling.

<Method of producing aqueous anticorrosion paint>
The aqueous anti-corrosive paint is prepared by synthesizing an epoxy resin emulsion, a water-soluble acrylic resin, an aqueous anti-rust agent, and an aqueous wetting agent to form an epoxy resin emulsion, a water-soluble acrylic resin, an aqueous anti-rust agent, Manufacture by mixing with a wetting agent. As an example, the manufacturing method is shown below.

(Epoxy resin emulsion)
A reaction solvent which mixes uniformly with water in an arbitrary ratio and an epoxy resin uniformly in this solution while heating and stirring uniformly A modified monomer (monomer) etc. which is reacted with the epoxy resin and dispersed in water, and a polymerization start Add the agent dropwise. Next, the reaction solution in which the dropping has been completed is heated and stirred for a certain period of time to advance the reaction of the epoxy resin monomer and the modified monomer to allow the water-dispersible modified epoxy resin used in the present invention (weight (Coalescent, polymer) is obtained. Then, a diluting solvent is added to the obtained modified epoxy resin reaction solution while stirring and mixed. By the above procedure, it is possible to obtain an epoxy resin emulsion.

Examples of the modifying monomer (monomer) include acrylic resins such as acrylic acid having a carboxyl group and methacrylic acid having a carboxyl group. Examples of the reaction solvent include ethylene glycol monobutyl ether.
In the production of the aqueous anticorrosion paint according to the present invention, an epoxy resin emulsion obtained by diluting the reaction solution together with a dilution solvent can be used without isolating the denatured modified epoxy resin.

(Water soluble acrylic resin)
An acrylic resin monomer (monomer) and a polymerization initiator are dropped into this solvent while heating and stirring a polymerization solvent which is uniformly mixed with water at an arbitrary ratio. Next, the reaction solution in which the dropping is completed is heated and stirred for a certain period of time to advance the polymerization reaction of the acrylic resin monomer to obtain a water-soluble acrylic resin (polymer, polymer). The resulting water soluble acrylic resin is added to the reaction solution with stirring to the dilution solvent. A water-soluble acrylic resin solution can be obtained by the above procedure.
Examples of the acrylic resin monomer (monomer) include (meth) acrylic acid, methyl methacrylate, butyl (meth) acrylate, hydroxyethyl methacrylate and styrene.

Examples of the polymerization solvent include ethylene glycol monobutyl ether.
In the production of the aqueous anticorrosion paint according to the present invention, a water-soluble acrylic resin solution obtained by diluting the reaction solution together with a dilution solvent can be used without isolating the water-soluble acrylic resin obtained by this polymerization reaction. .

(Water-based anticorrosive paint)
The aqueous anti-corrosive paint is obtained by stirring and mixing an epoxy resin emulsion, a water-soluble acrylic resin solution, an aqueous anti-rust agent, an aqueous wetting agent and a dilution solvent at room temperature in a container.

<Water-based anticorrosion coated metal products>
The aqueous anticorrosion coated metal product according to the present invention is a metal product coated with the aqueous anticorrosion paint according to the present invention. The aqueous anticorrosion paint according to the present invention does not matter the type, material, size, use and the like of the metal product to be coated. Examples of the material of the metal product include iron, aluminum, and alloys of these. The surface of the metal product may be plated with, for example, tin, zinc or the like, or may be subjected to substrate adjustment with shot blasting, sanding, a brush or the like. Examples of types of metal products include H-type steel, emergency stairs, concrete embedded reinforcing bars, concrete embedded metal fittings, construction materials such as steel frames and anchor bolts, machine parts such as press dies, and metal parts such as metal fittings.

(Film thickness)
The film thickness of the coating film by the aqueous anticorrosion paint in the aqueous anticorrosion coating metal product according to the present invention is 3 μm or more and 20 μm or less as the film thickness after drying after coating. If the film thickness of the coated film after drying is less than 3 μm, the thickness of the coated film becomes nonuniform, causing a difference in the strength of the coated film and causing cracking or peeling of the coated film starting from the portion where the coating film strength is reduced Damage is likely to occur. And since the water | moisture-content which is a corrosion cause substance infiltrates from damage, such as this crack and peeling, the antirust performance of water-based anticorrosion paint falls. When the film thickness of the coating after drying exceeds 20 μm, the radius of curvature becomes large at the time of bending, etc., so that damage such as cracking or peeling tends to occur, and the substance causing corrosion enters and the antirust effect decreases. . The film thickness can be measured in accordance with JIS K5600 (1999).
The film thickness of the aqueous anticorrosion paint formed on the aqueous anticorrosion paint metal product is preferably 5 μm or more and 15 μm or less.

(Painting method)
There is no restriction | limiting in the coating method to the metal product of the water-based anticorrosion paint which concerns on this invention, According to the shape and magnitude | size of the metal product which is a to-be-coated article, various coating methods can be selected suitably. For example, spray coating, brush coating, dip coating and the like can be mentioned.

There is no limitation on the method of setting the film thickness after drying of the aqueous anti-corrosive paint to 3 μm or more and 20 μm or less, and the coating may be performed such that the film thickness after drying is 1 μm or more and 20 μm or less. Coating may be performed so that the film thickness after drying is 3 μm or more and 20 μm or less by repeating and coating a plurality of times repeatedly.
There is no restriction on the method of drying the aqueous anti-corrosive paint, and any method such as forced drying by air blowing, heat drying, natural drying and the like can be adopted.

  As described above, the aqueous anticorrosive paint according to the present invention contains the (modified) epoxy resin and the water-soluble acrylic resin having a predetermined glass transition point, so that the strength and the flexibility can be obtained while the coated film after drying is a thin film. It has it. For this reason, the coating film of a thin film can follow for a long time also expansion, contraction, etc. of a coated object such as a metal product after coating, and damage such as cracking or peeling of the coating film hardly occurs. Therefore, the antirust performance is high, sustained for a long time, and exhibited. After painting, metal products and the like are stored outdoors for a long period of time, and even if used, the coating film is unlikely to be cracked or peeled off, and has excellent anticorrosion performance over a long period of time. It is also possible to respond to differences in usage environments such as seasonal changes, environmental changes, and coastal areas susceptible to salt damage.

  In addition, the aqueous anti-corrosive paint according to the present invention can be easily dispersed uniformly in water by containing a water-soluble acrylic resin having a predetermined acid value, so that the paint film becomes a thin film, so that the paint film is formed. It becomes possible to improve the performance, and the long-term anticorrosion performance of the coating film is improved.

  Furthermore, the aqueous anticorrosion coating according to the present invention can make the coating film a thin film, and because it has hydrophilicity and a small amount of low molecular components in the coating film, the coating film prevents adhesion to concrete. It is also excellent in adhesion performance with concrete. For this reason, construction materials, such as a reinforcing bar coated with the aqueous | water-based anticorrosion paint which concerns on this invention, can be used as it is, without removing a coating film, and can achieve a labor saving.

  And the aqueous anticorrosion paint according to the present invention is an aqueous paint which does not contain an organic solvent which is hardly soluble or insoluble in water, and since the content of the organic solvent can be reduced, the risk of ignition is low, and the handling is performed. Is easy. In addition, since there is little risk of polluting the environment with volatile organic compounds (VOCs) and measures for volatile organic compounds are not required, manufacturing costs and use costs can be reduced.

  In addition, the aqueous anticorrosion paint according to the present invention is easy to handle because it has a low viscosity, and is also excellent in wettability (wettability, wetting property) to an object to be coated. Moreover, since the film forming performance of the paint is excellent, uniform and thin film coating is possible, and the unpainted part of the paint can be prevented. And since it is a water-based paint which does not need baking, a special apparatus is not required and there is no restriction | limiting about the coating method and the drying method. Therefore, it is possible to paint and dry by a suitable method according to the shape, size, etc. of a thing to be coated, and can be used for various metal products.

  That is, taking advantage of this feature, various arbitrary coating methods such as spray coating, brush coating, dip coating, etc., to metal products having various sizes and weights of reinforcing bars, anchor bolts, metal fittings etc embedded in concrete It is possible to paint uniformly and thin film.

  Hereinafter, examples in which the effects of the present invention are confirmed will be described. The present invention is not limited to this embodiment.

(Preparation of epoxy resin emulsion)
In a flask equipped with a dropping funnel, a condenser for cooling, and a stirrer, 267 parts by mass of ethylene glycol monobutyl ether (butyl cellosolve manufactured by Sankyo Kagaku Co., Ltd.) as a reaction solvent, bisphenol A epoxy resin (epicoat 834, oiled shell) 240 parts by mass of Epoxy Co., Ltd. (epoxy equivalent 230 to 270) was added, and the mixture was heated to 165 to 175 ° C. while stirring under a nitrogen stream. In this flask, 39 parts by mass of methyl methacrylate (manufactured by Mitsubishi Gas Chemical Co., Ltd.), 43 parts by mass of butyl methacrylate (manufactured by Mitsubishi Gas Chemical Co., Ltd.), and 28 parts by mass of styrene (manufactured by Asahi Kasei Chemicals Co., Ltd.) A mixture of 50 parts by mass of methacrylic acid (manufactured by Mitsubishi Gas Chemical Co., Ltd.) and 4 parts by mass of t-butylperoxybenzoate (Perbutyl Z manufactured by NOF Corporation) was dropped over 1 hour. After completion of the dropwise addition, the mixture was further heated and stirred at 165 to 175 ° C. for 2 hours. Thus, a reaction solution containing the modified epoxy resin A was obtained.

  A dilution solvent consisting of 165 parts by mass of water and 164 parts by mass of 28% aqueous ammonia was added to the obtained reaction solution while stirring to obtain an epoxy resin emulsion Ae. The composition of the resulting epoxy resin emulsion Ae is shown in Table 1. In addition, the value of the mass part of an epoxy resin emulsion makes the whole epoxy resin emulsion a standard (1000 mass parts).

  Further, modified epoxy resins B to E were obtained under the same reaction conditions as the modified epoxy resin A with the monomer component composition shown in Table 1. The diluted solvent described in Table 1 was added to the reaction solution containing the modified epoxy resin obtained while stirring to obtain epoxy resin emulsions Be to Ee. The compositions of the resulting epoxy resin emulsions Be to Ee are described in Table 1.

(Non-volatile content of epoxy resin emulsion)
The resin non-volatile component content of the obtained epoxy resin emulsions Ae to Ee was measured by a heating residue measurement method (heating at 105 ° C. for 1 hour specified in JIS K 5601-1-2). The results are shown in Table 2. Each obtained non-volatile component content rate was used for calculation of resin content of each epoxy resin emulsion in manufacture of a water-based anticorrosion paint mentioned below.

(Viscosity of epoxy resin emulsion)
The viscosities of the epoxy resin emulsions Ae to Ee were measured at 25 ° C. using a Brookfield viscometer (DV-1 Prime Viscometer, manufactured by Brookfield engineering Laboratorics). The results are shown in Table 1.

(Preparation of water-soluble acrylic resin solution)
In a flask equipped with a dropping funnel, a condenser for cooling, and a stirrer, 392 parts by mass of ethylene glycol monobutyl ether (butyl cellosolve manufactured by Sankyo Chemical Co., Ltd.) as a polymerization solvent is added and the mixture is stirred at 165 to 175 ° C. under a nitrogen stream. It warmed up. 130 parts by mass of methacrylic acid (manufactured by Mitsubishi Gas Chemical Co., Ltd.), 100 parts by mass of methyl methacrylate (manufactured by Mitsubishi Gas Chemical Co., Ltd.), and 100 parts by mass of styrene (manufactured by Asahi Kasei Chemicals Co., Ltd.) A mixture of 70 parts by mass of butyl acrylate (manufactured by Mitsubishi Chemical Corporation) and 8 parts by mass of t-butylperoxybenzoate (Perbutyl Z manufactured by NOF Corporation) was dropped over 1 hour. After completion of the dropwise addition, the mixture was further heated and stirred at 165 to 175 ° C. for 1 hour. Thus, a reaction solution containing the water-soluble acrylic resin A was obtained.

  A dilution solvent consisting of 100 parts by mass of water and 100 parts by mass of 28% ammonia water was added to the obtained reaction solution with stirring to dilute, and a water-soluble acrylic resin solution As was obtained. The composition of the obtained water-soluble acrylic resin solution As is shown in Table 2. In addition, the value of the mass part of water-soluble acrylic resin makes the whole water-soluble acrylic resin a standard (1000 mass parts).

  In addition, reaction components containing water-soluble acrylic resins B to M were obtained under the same polymerization conditions as the water-soluble acrylic resin A with the monomer component composition shown in Table 2. The dilution solvents listed in Table 2 were added to the reaction solution containing the obtained water-soluble acrylic resin while stirring to obtain water-soluble acrylic resin solutions Bs to Ms in the same manner. The compositions of the obtained water-soluble acrylic resin solutions Bs to Ms are shown in Table 2.

(Glass transition point of water-soluble acrylic resin)
Differential scanning calorimetry according to the definition of JIS K7121 for the measurement sample obtained by heating and drying the reaction solution containing the obtained water-soluble acrylic resins A to M according to the definition of JIS K5601-1-2 at 105 ° C. for 1 hour The glass transition point was measured with an instrument (Perkin Elmer DSC-7). The results are shown in Table 2.

(Acid value of water-soluble acrylic resin)
The reaction solution containing the obtained water-soluble acrylic resins A to M was diluted with a mixed solvent of toluene: ethanol = 2: 1 in volume ratio, and the measurement was performed according to the definition of JIS K5601-2-1. The results are shown in Table 2.

(Nonvolatile content of water-soluble acrylic resin solution)
The resin non-volatile component content of the obtained water-soluble acrylic resin solutions As to Ms was measured by a heating residue measurement method (heating at 105 ° C. for 1 hour specified in JIS K 5601-1-2). The results are shown in Table 2. The obtained value of each non-volatile component content was used for calculation of each water-soluble acrylic resin content in manufacture of the aqueous | water-based anticorrosion paint mentioned later.

(Viscosity of water-soluble acrylic resin solution)
The viscosities of the water-soluble acrylic resin solutions As to Ms were measured at 25 ° C. using a Brookfield viscometer (DV-1 Prime Viscometer, manufactured by Brookfield engineering Laboratorics). The results are shown in Table 2.

(Water-based rust inhibitor)
The aqueous antirust agent is 37 parts by mass of dinolyl naphthalene sulfonic acid (CARBONE SCIENTIFIC CO., LTD. Made) as an organic acid, 23 parts by mass of octanoic acid (made by Tokyo Chemical Industry Co., Ltd.), and triethanolamine (Tokyo) Obtained by directly mixing 40 parts by mass of a product of Kasei Kogyo Co., Ltd. in a container at room temperature. This aqueous anticorrosive agent is referred to as aqueous anticorrosive agent A. In addition, the value of the mass part of an aqueous | water-based rust preventive agent makes the whole aqueous | water-based rust preventive agent a reference (100 mass parts).

  With the component compositions shown in Table 3, aqueous rust inhibitors B to D were obtained under the same conditions as the aqueous rust inhibitor A.

(Nonvolatile content of aqueous rust inhibitor)
In the same manner as in the case of the aqueous acrylic resin solution, the content of non-volatile components contained in the aqueous anticorrosive agents A to D was measured. The results are shown in Table 3. Each value of the obtained non-volatile component content rate was used for calculation of each aqueous | water-based antirust agent content in manufacture of the aqueous | water-based anticorrosion paint mentioned later.

(Aqueous wetting agent)
As the aqueous wetting agent, those shown in Table 4 were used in the production of an aqueous anticorrosive coating described later.

(Nonvolatile content of aqueous wetting agent)
In the same manner as in the case of the aqueous acrylic resin solution, the content of non-volatile components contained in the aqueous wetting agents A to E was measured. The results are shown in Table 4. Each value of the obtained non-volatile component content was used for calculation of each aqueous wetting agent content in manufacture of the aqueous | water-based anticorrosion paint mentioned later.

(Manufacture of water-based anticorrosion paint)
In a container containing 487 g of water, 384 g of epoxy resin emulsion Ae as an epoxy resin, 99 g of a water-soluble acrylic resin solution As as a water-soluble acrylic resin, 20 g of an aqueous rust inhibitor A, and 10 g of an aqueous wetting agent B The contents were stirred and mixed in a container to obtain a paint 1 (Example) which is an aqueous anticorrosion paint. The composition of paint 1 is shown in Table 5.
In addition, the value of an epoxy resin and a water-soluble acrylic resin describes the value computed from the injection amount of an epoxy resin emulsion and a water-soluble acrylic resin solution, respectively.

  Coatings 2 to 17 (Examples) are prepared by mixing the components shown in Tables 1 to 4 and the components having physical properties with water in the same manner as Paint 1 at the ratios shown in Table 5 respectively. Manufactured.

(Nonvolatile content of water-based anticorrosion paint)
In the same manner as in the case of the aqueous acrylic resin solution, the content of non-volatile components contained in the paint 1 to the paint 17 was measured. The results are shown in Table 5.

(Epoxy resin content to resin component of water-based anticorrosion paint)
The epoxy resin content relative to the resin component of the aqueous anti-corrosive paint is an epoxy resin content calculated by multiplying the actual usage amount (parts by mass) of the epoxy resin emulsion by the value of the epoxy resin component content in the epoxy resin emulsion. The resin content calculated by multiplying the used amount (parts by mass) of the emulsion by the value of the nonvolatile component content of the epoxy resin emulsion and the used amount (parts by mass) of the water-soluble acrylic resin solution It was determined by dividing by the total amount of resin content calculated by multiplying the amount. The results are shown in Table 5.

  Furthermore, in the same manner as in the paint 1, the paint 21 to the paint 30 (comparative example) are prepared by stirring and mixing the components having the compositions and physical properties shown in Tables 1 to 4 at the ratios shown in Table 6, respectively. Manufactured. The non-volatile component of each paint was measured to calculate the epoxy resin content. The results are shown in Table 6.

(Evaluation test)
According to the following method, evaluation experiments of rust resistance of paints 1 to 17 and paints 21 to 30 and adhesion of concrete were carried out.

(Test body)
Deformed steel bars with a standard diameter of 25 mm (JIS G3112.SD345.D25) (rebars) at normal temperature (25 ° C) in the immersion tank filled with paint 1 to paint 17 (example) and paint 21 to paint 30 (comparative example) Soak in. After the entire object to be coated is immersed, it is taken out, allowed to stand at normal temperature (25 ° C.) for 24 hours and dried, and then test body 1 to test body 17 (example) and test body 21 to test body 30 (comparison Ex.
By the same dip coating as described above, the coating and drying with the coating material 1 was repeated to form a coating having a coating thickness of 25 μm to obtain a test body 31 (comparative example).

(Paint film thickness measurement)
The coating film thickness of test body 1 to test body 17 (example) and test body 21 to test body 31 (comparative example) is determined by an electromagnetic induction type film thickness meter (Kett Science Research Institute, Inc., LZ-200J). Ten points were measured in accordance with JIS K5600 (1999), and the average value was calculated to obtain a paint film thickness.

(Anti-rust performance evaluation)
The antirust performance evaluation of the aqueous anticorrosion paint according to the present invention is performed by using the test pieces 1 to 17 (examples) and the test pieces 21 to 31 (comparative examples) outdoors (Kagosashi, Kamiseishashi Kita, Each specimen was allowed to stand horizontally at a height of 1 cm on a concrete pavement surface, which is the ground surface of Nippon Chemical Paint Co., Ltd.) and exposed for 12 months, and then the appearance was visually observed.
The test piece in which rust was not observed visually was regarded as excellent in rust prevention performance (○), and the test body in which rust was observed was regarded as inferior in rust prevention performance (×). In addition, the cut surface of the test body was not subject to evaluation.

(Concrete adhesion performance evaluation)
The adhesion performance evaluation of the aqueous anticorrosion paint according to the present invention is based on the adhesion stress of the coated test body to the unpainted test body in accordance with the adhesion strength test method (JSCE-E 516-2003) of the epoxy resin coated rebar defined by the Japan Society of Civil Engineers The degree ratio was measured at a time after coating drying.
As a result of measurement, those having an adhesion stress ratio of 85% or more were considered to be excellent in adhesion performance.

(Bending performance evaluation)
The anticorrosion performance evaluation of the aqueous anticorrosion paint according to the present invention, test body 1 to test body 17 (example), and test body 21 to test body 31 (comparative example) When press bending was carried out at 90 degrees using Ogra-made HBB-32 HPW), the occurrence of cracking and peeling of the coating film in the bent portion was visually observed. The test piece in which no cracking or peeling of the coating film was observed in the bent portion was excellent in flexibility (O), and the test body in which cracking or peeling was observed was inferior in flexibility (X).

<Example>
The evaluation test results of the test bodies 1 to 17 (examples) are described in Table 5.

  The occurrence of rust was not visually confirmed in any of the test bodies 1 to 17. Further, the adhesion stress ratio of each of the test bodies 1 to 15 was 90% or more, which was superior to 85% of the standard (JSCE-E 516-2003) defined by the Japan Society of Civil Engineers. In particular, test pieces 1 to 4, 6 and 8 to 11 had very excellent adhesion stress ratio of 97% or more.

The specimens 1 to 17 were cracked in the 90 ° bending performance evaluation with a film thickness after drying of 3 μm or more and 20 μm or less, and peeling was not confirmed.

  Paints 1 to 17 are excellent in anti-corrosion performance of metal products and the like which maintain and exhibit anti-corrosion effect for a long period of 12 months while being a thin film having a film thickness of 3 μm to 20 μm after drying. It is a paint excellent in adhesion performance with concrete.

Comparative Example
The evaluation test results of the test bodies 21 to 31 (comparative examples) are described in Table 6.

The occurrence of rust was visually confirmed at the corners of the test pieces of the test pieces 21 to 26, 28 and 30.
The glass transition point of the water-soluble acrylic resin J contained in the paint 21 applied to the test body 21 is less than 0 ° C. For this reason, when the coating film is softened and the strength of the coating film is insufficient, damage such as cracking or peeling of the coating film occurs starting from the portion where the coating film strength is reduced, and corrosion causing substances such as water infiltrate. As a result, rust was generated on the test body 21. Therefore, the paint 21 was inferior in antirust performance.
The glass transition point of the water-soluble acrylic resin K contained in the paint 22 applied to the test body 22 exceeds 125 ° C. For this reason, when the coating film is cured and the flexibility of the coating film is reduced, damage such as cracking or peeling of the coating film occurs from the point where the flexibility is reduced as a base point, and a corrosion source substance such as water penetrates As a result, rust was generated on the test body 22. In addition, cracking and peeling of the coating occurred even at 90 ° bending performance, and the flexibility was inferior. Accordingly, the paint 22 was inferior in antirust performance.

The acid value of the water-soluble acrylic resin L of the paint 23 applied to the test body 23 is less than 80 mg / KOH. For this reason, when the thickness of the coating film becomes nonuniform, the strength of the coating film becomes nonuniform, and damage such as cracking or peeling of the coating film occurs starting from the portion where the coating film strength is reduced As a substance causing corrosion enters, rust occurs on the test body 23. In addition, since the strength of the coating film is nonuniform, cracking and peeling of the coating film occurred even at 90 ° bending performance, and the flexibility was inferior. Accordingly, the paint 23 was inferior in antirust performance.
The acid value of the water-soluble acrylic resin M of the paint 24 applied to the test body 24 exceeds 240 mg / KOH. For this reason, the wettability of the coating film after drying becomes too high, and as a result of containing corrosion causing substances such as water in the coating film, rust occurs on the test body 24. Therefore, the paint 24 was inferior in antirust performance.

  The content of the resin component of the paint 25 applied to the test body 25 is less than 10% by mass. For this reason, the coating-film formation component in the coating material 25 decreases too much, it is difficult to obtain the coating-film thickness, and the film thickness is 2 μm. Therefore, when the coating film strength is reduced, damage such as cracking or peeling of the coating film occurs starting from the portion where the coating film strength is reduced, and corrosion causing substances such as moisture infiltrate and rusting in the test body 25 There has occurred. In addition, since the thickness of the coating was thin and the strength was low, cracking and peeling of the coating occurred even at 90 ° bending performance, and the flexibility was inferior. Therefore, the paint 25 was inferior in antirust performance.

The content of the aqueous anticorrosive agent A of the paint 26 applied to the test body 26 based on the non-volatile components is less than 0.1% by mass. For this reason, rust prevention performance fell and the test body 26 produced rust. Therefore, the paint 26 was inferior in antirust performance.
The content of the paint 27 applied to the test body 27 based on the non-volatile component of the aqueous rust inhibitor A exceeds 5% by mass, and thus the rust prevention performance is excellent. However, the lubricity of the coating surface after drying is increased, and the contact resistance between the coating and drying after drying decreases. Accordingly, the paint 27 was inferior in adhesion performance between the metal product and the concrete.

The content of the aqueous wetting agent B of the paint 28 applied to the test body 28 based on the non-volatile components is less than 0.1% by mass. For this reason, the wettability is lowered and the coating film becomes uneven, causing a difference in the strength of the coating film and causing damage such as cracking or peeling of the coating film starting from the portion where the coating film strength is lowered. The corrosion causing substance, such as, caused rust on the test body 28. In addition, since the strength of the coating film is nonuniform, cracking and peeling of the coating film occurred even at 90 ° bending performance, and the flexibility was inferior. Therefore, the paint 28 was inferior in antirust performance. Therefore, the paint 28 was inferior in antirust performance.
Since the content of the aqueous wetting agent B based on the non-volatile component of the paint 29 applied to the test body 29 exceeds 5% by mass, it is excellent in rust prevention performance. However, the lubricity of the coating surface after drying is increased, and the contact resistance between the coating and drying after drying decreases. Accordingly, the paint 29 was inferior in adhesion performance between the metal product and the concrete.

  Since the amount of epoxy resin with respect to the total amount of resin components of the paint 30 applied to the test body 30 is less than 30% by mass, the amount of the epoxy resin excellent in rust prevention in the coating is small, and the portion where the coating strength decreases The test body 30 was rusted due to the occurrence of damage such as cracking or peeling of the coating film and the entry of a corrosion-causing substance such as water. Therefore, the paint 30 was inferior in antirust performance.

  The test body 33 was repeatedly coated with the paint 1 to a coating thickness of 25 μm, so the radius of curvature increased in 90 ° bending performance and cracking and peeling of the coating occurred. Therefore, when the coating film thickness exceeded 20 μm, the flexibility was inferior.

Claims (2)

An aqueous anti-rust coated metal product, which is embedded in the concrete which has been subjected to water Seibosabi paint,
The aqueous anti-corrosive paint contains an epoxy resin emulsion, a water-soluble acrylic resin, an aqueous anti-rust agent, and an aqueous wetting agent,
The ratio of the amount of epoxy resin constituting the epoxy resin emulsion to the total amount of the resin constituting the epoxy resin emulsion and the water-soluble acrylic resin is 30% by mass or more.
The ratio of the total amount of the resin constituting the epoxy resin emulsion and the water-soluble acrylic resin to the aqueous rustproofing paint is 10% by mass to 40% by mass.
The ratio of the aqueous rust preventive to the aqueous rust preventive paint is 0.1% by mass or more and 5% by mass or less.
The ratio of the aqueous wetting agent to the aqueous anticorrosive coating is 0.1% by mass or more and 5% by mass or less,
The glass transition point of the water-soluble acrylic resin is 0 ° C. or more and 125 ° C. or less, and
The acid value of the water-soluble acrylic resin is 80 mg / KOH or more and 240 mg / KOH or less ,
An aqueous rust-proof coated metal product to be embedded in concrete, wherein the film thickness after drying of the water-based rust-preventive paint on the surface of the aqueous rust-proof coated metal product is 3 μm to 20 μm. The aqueous anticorrosion coated metal product embedded in concrete according to claim 1, wherein the aqueous wetting agent is a polyether-modified silicone-based aqueous wetting agent.