JP6629539B2 - Anticorrosion coating composition, anticorrosion coating, substrate with anticorrosion coating, and method for producing the same - Google Patents

Description

  The present invention relates to a paint film selected from a deteriorated paint film surface, particularly a tar epoxy resin paint, a tar urethane resin paint, a modified epoxy resin paint, a modified urethane resin paint, an epoxy resin paint, a urethane resin paint, an organic zinc paint, an inorganic zinc paint and the like. Without removing the deteriorated layer of the deteriorated coating film formed by the above, even on a wet surface where free moisture is attached to the surface of the deteriorated coating film, while having excellent corrosion protection, Anticorrosion coating composition capable of forming a coating film having excellent adhesion, an anticorrosion coating film formed from the anticorrosion coating composition, a substrate with an anticorrosion coating film coated with the anticorrosion coating film, and The present invention relates to a method for producing a substrate with an anticorrosion coating.

  For large steel structures such as ships, land structures, bridges, etc., to prevent corrosion, tar epoxy resin paint, tar urethane resin paint, modified epoxy resin paint, modified urethane resin paint, epoxy resin paint, urethane resin paint, It is coated with an anticorrosion coating film using an anticorrosion paint such as an organic zinc paint and an inorganic zinc paint. However, the surface of the anticorrosion coating deteriorates due to aging, outdoor exposure, submersion, and the like, and requires periodic repair. When the repair coating is performed with a general anticorrosive paint without performing a pre-treatment on the deteriorated paint film, sufficient adhesion between the deteriorated paint film and the repair-coated anticorrosive paint film cannot be obtained. There is a problem that cracks, peeling, etc. occur.

  Conventionally, as a countermeasure to the above-mentioned problem, when applying a repair paint on the surface of the deteriorated coating film, the deteriorated layer of the deteriorated coating film is removed by blast treatment or an electric tool, a hand tool, a water jet, etc., and then repaired. The paint has been painted. However, since the removal of the deteriorated layer requires a great deal of labor and cost, there is a demand for a repair paint that can be applied by a simple pretreatment such as water washing, which does not require such removal treatment. Furthermore, in order to reduce the drying process of the deteriorated coating film washed with water, even if repair coating is performed on the wet surface of the deteriorated coating film, it is possible to form a coating film having excellent anticorrosion properties that does not cause problems such as cracking and peeling. If an anticorrosive paint composition can be developed, it is difficult to completely dry the surface of a deteriorated coating such as a ballast tank. It is also suitable for outdoor repair applications that are affected by the weather, and is effective in reducing labor and cost for such repairs.

  Patent Document 1 discloses that 1 to 30 parts by weight per 100 parts by weight of an organic solvent type or solventless type paint containing 100 parts by weight of an organic resin or a solventless coating containing an epoxy resin having one or more epoxy groups in one molecule and an amine-based curing agent as resin components. A coating composition characterized by containing the above-mentioned coating composition on the surface of a deteriorated coating of a coating formed from a highly anticorrosive coating such as a tar epoxy resin coating, and a coating composition characterized by containing water. A method is disclosed.

  Patent Document 2 discloses a tar epoxy resin coating, a tar urethane resin coating, a modified epoxy resin coating, a modified urethane resin coating, an epoxy-polyamine resin coating and an epoxy urethane resin coating, and An epoxy-polyamine resin-based coating material containing, as a resin component, an epoxy resin having one or more epoxy groups in one molecule and an amine-based curing agent on a deteriorated coating film having a water content of 0.3 to 5% by weight. A repair coating method characterized in that a paint is applied.

  Patent Document 3 discloses that a two-part reaction-curable epoxy resin composition containing no organosilicate ester contains water on at least one of the epoxy compound side and its hardener side, thereby providing an eye having thixotropic properties during mixing. Stoppers are disclosed.

  In Patent Literature 1, application to a substrate having a deteriorated coating film has been studied, and it has been clarified that the composition disclosed herein has excellent initial adhesion to the deteriorated coating film. However, in general, it is known that the adhesion of a coating film is reduced by exposure to salt water and a high-temperature and high-humidity environment. In a coating film formed by the composition disclosed in Patent Document 1, However, the adhesion to a deteriorated coating film for anticorrosion applications, which is often exposed to the above environment, is insufficient. In addition, the composition disclosed herein has not been studied for coating a deteriorated coated substrate having a wet surface, but has insufficient adhesion to a deteriorated coated substrate having a wet surface. .

  Patent Document 2 discusses a repair coating method for a deteriorated coating film having a predetermined moisture content in the coating film. In the paragraph [0016], moisture may be condensed on the coating film surface. It is described that it is desirable that the surface of the coating film be free of free moisture by visual inspection. In the examples of Patent Document 2, various moisture contents of the deteriorated coating film are measured by the Karl Fischer method, but in the paragraph [0017], there is free moisture on the surface of the coating film to be measured. In this case, it is described that after removal, the water content is measured by the Karl Fischer method. Therefore, there is no study on coating a substrate with a deteriorated coating film having a wet surface. Further, the epoxy-polyamine resin-based coating disclosed in Patent Document 2 has no technical idea of positively including water in the coating composition, and has a deteriorated coating film having a wet surface. Adhesion to is poor.

  Patent Literature 3 does not consider coating a substrate with a deteriorated coating film or a wet surface thereof, but the composition disclosed herein has insufficient adhesion to any substrate.

JP 2001-29886 A JP 2001-300417 A JP-A-6-172697

  The present invention is to solve the problems in the prior art described above, the surface of the deteriorated coating film, especially tar epoxy resin paint, tar urethane resin paint, modified epoxy resin paint, modified urethane resin paint, epoxy resin paint, On the surface of a deteriorated coating formed by a coating selected from urethane resin coatings, organic zinc coatings, inorganic zinc coatings, etc., without removing the deteriorated layer, the deteriorated coating further has a wet surface Anticorrosion coating composition, anticorrosion coating, base material with anticorrosion coating, and method for producing base material with anticorrosion coating capable of forming coating film having excellent anticorrosion properties and excellent adhesion even in state It is intended to provide.

  The present inventors have conducted intensive studies on a method for solving the above-mentioned problem, and as a result, for an epoxy resin-based anticorrosion paint, selected an amine curing agent having an affinity for water, and a predetermined amount in the anticorrosion paint. It has been found that the above objects can be achieved by adding water and a flat pigment, and the present invention has been completed.

The configuration of the present invention is as follows.
A coating composition that can be applied to a wet surface of a substrate coated with a deteriorated coating film,
Epoxy resin (A),
At least one amine curing agent (B) selected from polyoxyalkylene polyamines, Mannich-modified amines and ketimines;
1 to 15 parts by weight of water (C) with respect to 100 parts by weight of the coating composition (non-volatile content);
A flat pigment (D),
An anticorrosion paint composition comprising:

  The deteriorated coating film is formed of one kind of paint selected from tar epoxy resin paint, tar urethane resin paint, modified epoxy resin paint, modified urethane resin paint, epoxy resin paint, urethane resin paint, organic zinc paint, inorganic zinc paint, and the like. It is preferable that the coating film is formed.

  The amine curing agent (B) preferably contains at least a polyoxyalkylene polyamine among polyoxyalkylene polyamines, Mannich-modified amines and ketimines.

  It is preferable that the amine curing agent (B) contains at least a polyoxyalkylene polyamine in an amount of 0.01 to 20 parts by weight (non-volatile content) based on 100 parts by weight (non-volatile content) of the anticorrosive coating composition. .

It is preferable that the anticorrosion coating composition further contains at least one selected from the group consisting of a reactive diluent (E1) having an epoxy group and a modified epoxy resin (E2).
The anticorrosion coating film according to the present invention is formed from the anticorrosion coating composition.

  The substrate with an anticorrosion coating according to the present invention is obtained by coating the surface of the substrate with a degraded coating with an anticorrosion coating formed from the anticorrosion coating composition.

  The method for producing a substrate with an anticorrosion coating according to the present invention includes a step of applying the anticorrosion coating composition to the surface of the substrate with a degraded coating, and curing the coated anticorrosion coating composition to prevent corrosion. And forming a coating film.

  The anticorrosion coating composition according to the present invention is selected from tar epoxy resin coating, tar urethane resin coating, modified epoxy resin coating, modified urethane resin coating, epoxy resin coating, urethane resin coating, organic zinc coating, inorganic zinc coating and the like. Without removing the degraded layer of the degraded coating film formed by the paint, the degraded coating film (hereinafter, referred to as a dried degraded coating film) having no free moisture attached to the surface, as well as the degraded coating film Even when applied to a wet surface, it is possible to form an anticorrosion coating film having excellent anticorrosion properties and excellent adhesion.

FIG. 1 is a schematic diagram showing an example of a top coat adhesion test of an anticorrosion coating.

  Hereinafter, the anticorrosion coating composition, the anticorrosion coating film, the substrate with the anticorrosion coating film, and the method for producing the anticorrosion coating film of the present invention will be described in detail including preferred embodiments.

<Anti-corrosion paint composition (also referred to as anti-corrosion paint)>
The anticorrosion coating composition according to the present invention comprises an epoxy resin (A), at least one amine curing agent (B) selected from polyoxyalkylene polyamines, Mannich-modified amines and ketimines, and the coating composition 100 described above. It is characterized by containing 1 to 15 parts by weight of water (C) and flat pigment (D) with respect to parts by weight (non-volatile content).

  The anticorrosion coating composition according to the present invention preferably further contains at least one member selected from the group consisting of a reactive diluent (E1) optionally having an epoxy group and a modified epoxy resin (E2).

<Base material with deteriorated coating film>
The substrate with a deteriorated coating film according to the present invention is, for example, a metal, wood, plastic, stone, slate, concrete, mortar, or the like, coated with a deteriorated coating film formed of a general anticorrosive coating composition or the like. Have been. In particular, one type of paint selected from tar epoxy resin paint, tar urethane resin paint, modified epoxy resin paint, modified urethane resin paint, epoxy resin paint, urethane resin paint, organic zinc paint, inorganic zinc paint, etc. It is preferably coated with a degraded coating film formed by an epoxy resin anticorrosive paint such as a tar epoxy resin paint, a modified epoxy resin paint, an epoxy resin paint, and an epoxy zinc paint. More preferably, it is coated with the deteriorated coating film.

<Wet surface>
In the present invention, the water content of the wet surface is determined by spraying water to the surface of the dried degraded coating film by spraying and uniformly attaching the water, and measuring the weight (unit: g) of the sprayed water. The amount of water adhering to the film surface (unit: g / m ² ) was examined. In the case where water has already adhered to the surface of the steel sheet or the deteriorated coating film to form a wet surface, the amount of water (unit: g / m ² ) on the wet surface is determined by, for example, the weight of the wet surface after drying. It can be measured by determining the decrease (unit: g).

The wet surface of the deteriorated coating film to which the anticorrosive coating composition according to the present invention is applied, in a preferred embodiment, when the surface of a non-water-absorbing substrate such as a steel plate is covered with the deteriorated coating film, Water of 5 to 45 g / m ² adheres to the surface of the coating film, and usually, the released water can often be visually confirmed. For example, a state in which moisture is attached to the surface of a deteriorated coating film of a large steel structure by rainfall, water washing, or condensation under high humidity is assumed as a wet surface. In particular, in closed spaces such as ballast tanks, high humidity tends to occur due to the water used for cleaning the deteriorated coating film and the residual water of the ballast water. Often occur.

<Epoxy resin (A)>
In the anticorrosion coating composition according to the present invention, the epoxy resin (A) is a polymer or oligomer having two or more epoxy groups in a molecule, and a polymer or oligomer formed by a ring-opening reaction of the epoxy group. Examples thereof include bisphenol type epoxy resins, glycidyl ester type epoxy resins, glycidylamine type epoxy resins, phenol novolak type epoxy resins, and cresol novolak type epoxy resins. Among these, bisphenol-type epoxy resins are preferred from the viewpoint that an anticorrosion coating film having excellent adhesion to a deteriorated coating film can be formed, and bisphenol-type epoxy resins of bisphenol A type and bisphenol F type are more preferable. Preferably, bisphenol A type epoxy resin is particularly preferred. The epoxy resin (A) can be used alone or in combination of two or more.

  Examples of the bisphenol A type epoxy resin include polycondensates of bisphenol A type diglycidyl ethers, and the bisphenol A type diglycidyl ethers forming the polycondensate include bisphenol A diglycidyl ether and bisphenol A polypropylene oxide diglycidyl ether, bisphenol A ethylene oxide diglycidyl ether, and the like.

  The epoxy resin (A) is liquid at room temperature before being cured by reaction with the amine curing agent (B) and the like, because it can form an anticorrosive coating exhibiting excellent adhesion to a deteriorated coating. Alternatively, a semi-solid material is preferable.

  The epoxy equivalent of the epoxy resin (A) is preferably from 150 to 1,000, more preferably from 150 to 800, particularly preferably from 180 to 700, from the viewpoint of anticorrosion properties and the like. The epoxy equivalent is calculated based on JIS K 7236.

  The epoxy resin (A) may be obtained by synthesizing according to a conventionally known method, or may be a commercially available product. Among the epoxy resins (A) used in the present invention, "E028" (manufactured by Ohtake Meishin Chemical Co., Ltd., bisphenol A type epoxy resin) as a liquid at normal temperature (a temperature of 15 to 25 ° C., hereinafter the same). , Epoxy equivalent 180-190, nonvolatile content 100%), "jER 807" (manufactured by Mitsubishi Chemical Corporation, bisphenol F type epoxy resin, epoxy equivalent 160-175, nonvolatile content 100%), "E-028-90X" (Xylene solution of bisphenol A type epoxy resin (828 type epoxy resin solution, epoxy equivalent 200 to 210, nonvolatile content 90%) manufactured by Otake Meishin Chemical Co., Ltd.) and the like. “JER 834” (manufactured by Mitsubishi Chemical Corporation, bisphenol A type epoxy resin, epoxy equivalent 230 to 270, nonvolatile content 100%), “E-8” 34-85X "(manufactured by Ohtake Meishin Chemical Co., Ltd.), a xylene solution of a bisphenol A type epoxy resin (834 type epoxy resin solution, epoxy equivalent 270 to 320, nonvolatile content 85%) and the like. As examples, "jER 1001" (manufactured by Mitsubishi Chemical Corporation, bisphenol A type epoxy resin, epoxy equivalent 450-500, nonvolatile content 100%), "E-001-75" (manufactured by Ohtake Akira Shin Chemical Co., Ltd.) Bisphenol A type epoxy resin xylene solution (1001 type epoxy resin solution), epoxy equivalent 600 to 660, nonvolatile content 75%) and the like.

  The epoxy resin (A) is preferably 5 to 40 parts by weight (nonvolatile content), more preferably 10 to 30 parts by weight (nonvolatile content) based on 100 parts by weight (nonvolatile content) of the anticorrosion coating composition of the present invention. Is desirably included.

  When the anticorrosion coating composition of the present invention is a two-component coating composition comprising a main component and a curing agent component, the epoxy resin (A) is included in the main component, and 100 parts by weight of the main component ( (Non-volatile content), preferably in an amount of 5 to 80 parts by weight (non-volatile content), more preferably 5 to 50 parts by weight (non-volatile content).

  In addition, the non-volatile component refers to a sufficiently reactive hardening of the anticorrosion coating composition in the anticorrosion coating composition according to the present invention containing a reactive component (eg, epoxy resin (A), amine curing agent (B), etc.). Means the weight percentage of the coating film composed of the paint. According to JIS K5601-1-2, a sample obtained by collecting 1 ± 0.1 g of the anticorrosive coating composition was heated at a heating temperature of 125 ° C. for 1 hour (under normal pressure) to obtain a residue after heating. , Calculated as the weight percentage of the heating residue relative to the coating composition.

Similarly, the nonvolatile content of each component of the anticorrosion coating composition according to the present invention can be calculated in accordance with JIS K5601-1-2.
<Amine curing agent (B)>
In the anticorrosion coating composition according to the present invention, as the amine curing agent (B), at least one amine curing agent selected from polyoxyalkylene polyamines, Mannich modified amines, and ketimines having affinity for water is used. contains.

  The curing agent component of the anticorrosion coating composition according to the present invention includes, in addition to polyoxyalkylene polyamines, Mannich-modified amines, and ketimines, which are amine curing agents (B), a general epoxy resin-based anticorrosion coating. Any amine curing agent other than the amine curing agent (B) used (eg, polyamidoamine, aliphatic amine, alicyclic amine, aromatic amine, aliphatic amine adduct, etc.) can be included.

In particular, the curing agent component contains a polyoxyalkylene polyamine alone or the polyoxyalkylene polyamine and another amine curing agent (B) as the amine curing agent (B), and optionally comprises an amine curing agent. Any amine curing agent other than the agent (B) may be used in combination, and the formed anticorrosive coating film is not only a dried deteriorated coating film but also a deteriorated coating film having a wet surface, in particular, a water content on the surface of the deteriorated coating film. This is preferable because it tends to exhibit excellent adhesion to a deteriorated coating film having an adhesion amount of 5 to 45 g / m ² .

  That is, as the embodiment of the amine curing agent (B), (i) only polyoxyalkylene polyamines, (ii) polyoxyalkylene polyamines, Mannich-modified amines, (iii) polyoxyalkylene polyamines, and ketimines (Iv) Four aspects of polyoxyalkylene polyamines and Mannich modified amines and ketimines are excellent not only in adhesion to a dried deteriorated coating but also in adhesion to a deteriorated coating having a wet surface. Is preferred. Further, the curing agent component may include any amine curing agent other than the amine curing agent (B) in addition to the above (i) to (iv).

  When a polyoxyalkylene polyamine is used as the curing agent component in combination with another amine curing agent (B) or any amine curing agent other than the amine curing agent (B), 100 parts by weight of the anticorrosive coating composition (non-volatile ), As the amine curing agent (B), a polyoxyalkylene polyamine, preferably 0.01 to 20 parts by weight (non-volatile content), more preferably 1 to 10 parts by weight (non-volatile content), and particularly preferably Desirably, it is contained in an amount of 2 to 8 parts by weight (nonvolatile content).

  In the anticorrosion coating composition according to the present invention, the equivalent ratio (active hydrogen equivalent / epoxy equivalent) of the amine curing agent (B) and the epoxy resin (A) is preferably 0.3 to 1.5, More preferably, it is used in an amount of 0.4 to 1.0 from the viewpoint of curing speed, corrosion resistance and the like.

  Examples of the polyoxyalkylene polyamines used in the present invention include “Jeffamine D-230” (manufactured by Huntsman Japan KK, polyoxypropylenediamine, active hydrogen equivalent 60, nonvolatile content 100%), “Jeffamine D-400”. (Huntsman Japan K.K., polyoxypropylenediamine, active hydrogen equivalent 115), "Jeffamine D-2000" (Huntsman Japan K.K., polyoxypropylenediamine, active hydrogen equivalent 514) and "Jeffamine T- 403 "(manufactured by Huntsman Japan KK, polyoxypropylene triamine, active hydrogen equivalent: 81) and the like.

  Examples of the Mannich-modified amines used in the present invention include "MAD-204 (A)" (mannich-modified aliphatic polyamine, manufactured by Otake Akira Shinkagaku Co., Ltd., active hydrogen equivalent 202, nonvolatile content 65%), "ADEKA HARDNER" EH-342W3 "(manufactured by ADEKA Corporation, Mannich-modified polyamidoamine, active hydrogen equivalent 110)," Sunmide CX-1154 "(manufactured by Sanwa Chemical Co., Ltd., Mannich-modified aliphatic polyamine, active hydrogen equivalent 255), "Cardolite NX-4918" (manufactured by Cardlight, phenalcamine which is a Mannich-modified amine of cardanol and amine, active hydrogen equivalent 255, non-volatile content 80%), "Cardolite NC556X80" (manufactured by Cardlight, fenarcamine adduct, Active hydrogen equivalent 135), fenarca Examples include phenalkamide, which is a reaction product of a min and a carboxylic acid.

Examples of the ketimines used in the present invention include “Ancamine 2459” (manufactured by Air Products Inc., active hydrogen equivalent: 101, nonvolatile content: 80%) and the like.
Examples of the optional amine curing agent other than the amine curing agent (B) include “PA-290 (A)” (manufactured by Ohtake Meishin Chemical Co., Ltd., polyamideamine, active hydrogen equivalent 277, nonvolatile content 59%), “ Sunmide P-1003 (manufactured by Air Products Co., Ltd., aliphatic amine adduct, active hydrogen equivalent 125, nonvolatile content 60%), "AD-200P" (manufactured by Ohtake Meishin Chemical Co., Ltd.), aliphatic amine adduct (meta Epoxy adduct of xylene diamine), an active hydrogen equivalent of 155, and a nonvolatile content of 90%).

<Water (C)>
In the anticorrosion coating composition according to the present invention, the water (C) is used in an amount of 1 to 15 parts by weight, preferably 1 to 10 parts by weight, more preferably 1 to 100 parts by weight (nonvolatile content) based on the anticorrosion coating composition. Preferably, it is included in an amount of up to 7 parts by weight.

  If the water (C) in the anticorrosion coating composition is less than 1 part by weight, the adhesion between the deteriorated coating film and the formed anticorrosion coating film when coated on a deteriorated coating film having a wet surface is insufficient. It becomes. On the other hand, when the amount exceeds 15 parts by weight, the anticorrosion property of the anticorrosion coating film tends to decrease.

<Flat pigment (D)>
In the anticorrosion coating composition according to the present invention, the flat pigment (D) has a median diameter (D50) of 30 to 200 μm and an average aspect ratio (median diameter / average thickness) of 30 to 100. Is desirable from the viewpoint of improving the adhesion to the deteriorated coating film.

  The median diameter (D50) can be measured using a laser scattering diffraction type particle size distribution analyzer, for example, “SALD 2200” (manufactured by Shimadzu Corporation). The average thickness is observed from the horizontal direction with respect to the main surface of the flat pigment (D) using a scanning electron microscope (SEM), for example, “XL-30” (manufactured by Philips), and several tens to several hundreds are observed. The average value can be calculated by measuring the thickness of each pigment particle.

  Examples of the flat pigment (D) include mica, glass flake, and the like, which are inexpensive and easily available, and from the viewpoint of easily obtaining the effect of improving the adhesion by relaxing the internal stress of the coating film described above. Mica is preferred. Examples of the mica include “Szolite Mica 200-HK” (manufactured by West Japan Trading Co., Ltd., median diameter (D50): 65 μm, average aspect ratio: 54) and the like.

  The flat pigments (D) can be used alone or in combination of two or more.

  The flat pigment (D) is preferably 1 to 40 parts by weight with respect to 100 parts by weight (non-volatile content) of the anticorrosion coating composition of the present invention, since the flat pigment (D) can form an excellent anticorrosion coating film due to the above effects. Parts, more preferably 3 to 20 parts by weight.

  The reason why the anticorrosion coating film formed by the anticorrosion coating composition according to the present invention has excellent adhesion to the surface of the deteriorated coating film is that the anticorrosion coating film has an adhesive property ( The reason 1) and the adhesion to the deteriorated coating film surface having a wet surface (reason 2) are estimated as follows.

(Reason 1)
The deteriorated coating film, regardless of the type of resin in the paint forming the deteriorated coating film, is immersed in seawater or exposed to sunlight, whereby the surface changes from hydrophobic to hydrophilic. Tend. By adding a predetermined amount of water to the anticorrosion coating composition applied to the surface of the deteriorated coating film, the hydrophilicity of the coating material is increased, and the coating is easily wetted (easily adapted) to the surface of the deteriorated coating film, thereby improving adhesion. I do. Furthermore, by including the flat pigment in the anticorrosion coating composition, the internal stress of the anticorrosion coating film formed is reduced. Therefore, the anticorrosion coating composition according to the present invention has excellent adhesion to a dried deteriorated coating film.

(Reason 2)
By adding a specific amine curing agent having an affinity for water to the anticorrosion coating composition, when the anticorrosion coating composition is applied to the wet surface of the deteriorated coating film, it becomes a factor that hinders adhesion. The effect is to take in some or all of the free water adhering to the surface of the deteriorated coating film into the anticorrosive paint instead of flipping. Here, the amine curing agent having an affinity for water is at least one amine curing agent selected from polyoxyalkylene polyamines, Mannich-modified amines, and ketimines. Since the polyoxyalkylene polyamines have a highly polar ether bond in the molecule, the Mannich-modified amines have a hydroxyl group in the molecule, and thus have an affinity for water. Shows the effect of incorporating into anticorrosion paints. The ketimines react with moisture to produce an amine curing agent and a ketone, and have an effect of taking the released moisture into the anticorrosion paint. Further, by adding a predetermined amount of water to the anticorrosion coating composition, the hydrophilicity of the coating is increased, so that the deteriorated coating film surface is easily wetted (adapted) similarly to (Reason 1). In addition, the effect of taking in the above-mentioned free water is also improved. However, in the anticorrosion coating composition, a specific amine curing agent having an affinity for water, or simply including only one of a predetermined amount of water, the effect of incorporating the released water into the anticorrosion coating is not sufficient. It is not sufficient, and adhesion to a deteriorated coating film surface having a wet surface cannot be obtained.

  In order for the anticorrosion coating composition to exhibit excellent adhesion to the deteriorated coating film surface having a wet surface, the effect of taking in the released moisture into the anticorrosion coating alone is not sufficient, and a specific amine curing agent and By adding a flat pigment in addition to the predetermined amount of water, the effect of improving the adhesion by relaxing the internal stress of the formed anticorrosion coating film can be obtained as in (Reason 1). Therefore, the anticorrosion coating composition according to the present invention has an effect of taking in the released moisture into the anticorrosion coating, and a synergistic effect of an adhesion improving effect due to the relaxation of the internal stress. It has excellent adhesive properties.

<Other coating film forming components that can be added to the main component>
The main component of the anticorrosion coating composition according to the present invention is selected from the group consisting of a reactive diluent (E1) having an epoxy group and a modified epoxy resin (E2) as additives in addition to the epoxy resin (A). At least one of them.

As the reactive diluent (E1) having an epoxy group, for example, phenyl glycidyl ether, alkyl glycidyl ether (alkyl group having 1 to 15, preferably 11 to 15), versatic acid, glycidyl ester (R ₁ R ₂ R ₃ C-COO-Gly, R ₁ + R ₂ + R ₃ = alkyl group of C8 to C10, Gly: glycidyl group), α-olefin epoxide (CH ₃ — (CH ₂ ) n-Gly, n = 11 to 13, Gly: the same as above), 1,6-hexanediol diglycidyl ether _{(Gly-O- (CH 2)} 6 -O-Gly, Gly: the same as above), neopentyl glycol diglycidyl ether (Gly-O- CH ₂ —C (CH ₃ ) ₂ —CH ₂ —O-Gly, Gly: ibid), trimethylol Propane triglycidyl ether (CH ₃ —CH ₂ —C (CH ₂ —O-Gly) ₃ , Gly: same as above), alkylphenyl glycidyl ether (alkyl group having 1 to 20, preferably 1 to 5, carbon atoms, eg, methyl) Phenyl glycidyl ether, ethyl phenyl glycidyl ether, propyl phenyl glycidyl ether) and the like.

  Among these reactive diluents (E1) having an epoxy group, monofunctional phenyl glycidyl ether, alkyl glycidyl ether, and alkyl phenyl glycidyl ether have low viscosities, and thus have excellent diluting effect (low viscosity of paint). It is possible to contribute to the high solidification of the paint (it is possible to suppress the shrinkage of the paint film due to the evaporation of the solvent by increasing the content of the paint film forming component contained in the paint composition). It is preferable to improve the adhesion to the deteriorated coating film.

  The reactive diluent (E1) having an epoxy group can be used alone or in combination of two or more. Examples of such a reactive diluent (E1) having an epoxy group include “Epodil 759” (manufactured by Air Products Co., Ltd., alkyl (C12-C13) glycidyl ether, epoxy equivalent 285, nonvolatile content 100%), “Cardolite” 2513HP "(manufactured by Cardlight Co., Ltd., alkylphenol glycidyl ether, epoxy equivalent 400, nonvolatile content 100%).

  The reactive diluent (E1) having an epoxy group is preferably contained in the main component of the anticorrosion coating composition according to the present invention in an amount of from 0 to 40 parts by weight based on 100 parts by weight (non-volatile content) of the epoxy resin (A). Parts (non-volatile content), more preferably 0 to 20 parts by weight (non-volatile content).

Examples of the modified epoxy resin (E2) include a fatty acid-modified epoxy resin and a hydrogenated epoxy resin.
The fatty acid-modified epoxy resin used in the present invention is preferably a dimer acid-modified epoxy resin (A) having an epoxy equivalent of preferably 150 to 1,000, more preferably 170 to 700, and particularly preferably 400 to 600. . When the epoxy equivalent of the epoxy resin (A) exceeds 1,000, the crosslinked density of the cured coating film composed of the fatty acid-modified epoxy resin tends to be low, and the corrosion resistance inherent to the epoxy resin tends to be impaired.

  The dimer acid is a dimer of an unsaturated fatty acid and usually contains a small amount of a monomer or a trimer. Examples of the unsaturated fatty acid include carboxylic acids having 12 to 24, preferably 16 to 18, carbon atoms (including carbon atoms of a carboxyl group) and having one or two or more unsaturated bonds in one molecule. Compounds are used. Examples of such unsaturated fatty acids include fatty acids having one unsaturated bond, such as oleic acid, elaidic acid, and setreic acid; fatty acids having two unsaturated bonds, such as sorbic acid and linoleic acid; linoleic acid, arachidone Fatty acids having three or more unsaturated bonds such as acids are exemplified. Furthermore, fatty acids obtained from animals and plants can also be used, and examples thereof include soybean oil fatty acids, tall oil fatty acids, and linseed oil fatty acids.

  The amount of modification with the dimer acid in the fatty acid-modified epoxy resin is 4 to 30 parts by weight (nonvolatile), preferably 5 to 20 parts by weight (nonvolatile) based on 100 parts by weight (nonvolatile) of the epoxy resin (A). Desirably. If the amount of modification is less than 4 parts by weight (nonvolatile content), the resulting modified epoxy resin has low compatibility with aromatic solvents and insufficient flexibility. On the other hand, if the amount of modification exceeds 30 parts by weight (nonvolatile content), the anticorrosive properties and adhesion inherent to epoxy resins tend to be impaired.

  The fatty acid-modified epoxy resin is obtained by reacting the epoxy resin (A) having the above-mentioned preferred epoxy equivalent with dimer acid. When the epoxy equivalent of the epoxy resin (A) used for the fatty acid-modified epoxy resin is less than 150, it becomes difficult to synthesize a fatty acid-modified epoxy resin having a dimer acid modification amount of 4 parts by weight (nonvolatile content) or more. is there.

  The method for synthesizing the fatty acid-modified epoxy resin used in the present invention is not particularly limited, and a known method is used. For example, a method in which a solid or semi-solid epoxy resin is first synthesized at room temperature by a reaction between a liquid epoxy resin and a bisphenol or a reaction between epichlorohydrin and a bisphenol, and then a fatty acid is added and reacted to obtain a method (2). Step method), a method of simultaneously reacting a liquid epoxy resin, bisphenol, and a fatty acid (one-step method).

  In the two-step method, an epoxy resin is first synthesized at a temperature of 50 to 250 ° C, preferably 100 to 200 ° C, using a catalyst used in a usual epoxidation reaction. Specific examples of the catalyst used in this synthesis include alkali metal hydroxides such as sodium hydroxide, potassium hydroxide and lithium hydroxide; alkali metal alcoholates such as sodium methylate; lithium chloride, lithium carbonate and the like. Alkali metal salts; tertiary amines such as dimethylbenzylamine, triethylamine and pyridine; quaternary ammonium salts such as tetramethylammonium chloride and benzyltrimethylammonium chloride; organic phosphorus compounds such as triphenylphosphine, triethylphosphine and triphenylphosphine Lewis acids such as arsenic trifluoride, aluminum chloride, tin tetrachloride, and arsenic trifluoride diethyl ether complex; and methyl iodide adducts.

  Next, a predetermined amount of a fatty acid is added to the epoxy resin obtained as described above, and the epoxy resin is added at 100 to 200 ° C. in the presence of a catalyst such as a tertiary amine, a quaternary ammonium salt, and a methyl iodide adduct. The resin is reacted with the fatty acid. In addition, in the one-step method of simultaneously reacting the liquid epoxy resin, bisphenol, and fatty acid, a tertiary amine, a quaternary ammonium salt, a catalyst such as methyl iodide adduct is added to these components, and the mixture is heated at 100 to 200 ° C. The reaction is performed to synthesize a fatty acid-modified epoxy resin. The amount of the catalyst used in these reactions is preferably about 0.01 to 10,000 ppm, more preferably about 0.1 to 1,000 ppm, based on the total weight of the reactants.

  Examples of the fatty acid-modified epoxy resin include “KE-8174X90” (manufactured by KOLON Chemical Co., Ltd., xylene cut product, epoxy equivalent 230 to 270, nonvolatile content 90%), “DME-111” (manufactured by Ohtake Meishin Chemical Co., Ltd.) Xylene cut product, epoxy equivalent 260, nonvolatile content 90%) and the like.

  The hydrogenated epoxy resin used in the present invention is a normal temperature obtained by selectively performing a hydrogenation reaction on an epoxy resin having an aromatic ring having an epoxy equivalent of preferably 150 to 1,000 under pressure in the presence of a catalyst. And a liquid one is preferred.

  Examples of the epoxy resin having an aromatic ring include bisphenol type epoxy resins such as bisphenol A type epoxy resin, bisphenol F type epoxy resin and bisphenol S type epoxy resin; naphthalene type epoxy resin, phenol novolak epoxy resin, cresol novolak epoxy resin And novolak-type epoxy resins such as hydroxybenzaldehyde phenol novolak epoxy resin; polyfunctional epoxy resins such as glycidyl ether of tetrahydroxyphenylmethane, glycidyl ether of tetrahydroxybenzophenone, and epoxidized polyvinyl phenol;

  Particularly, among these epoxy resins having an aromatic ring, bisphenol A type epoxy resin, bisphenol F type epoxy resin, and phenol novolak type epoxy resin are preferable.

The hydrogenated epoxy resin can be produced by a conventionally known hydrogenation method. For example, the epoxy resin having an aromatic ring as a raw material is dissolved in an ether-based organic solvent such as tetrahydrofuran or dioxane, and reacted in the presence of a catalyst in which rhodium or ruthenium is supported on graphite (hexagonal crystal graphite). Thereby, the aromatic ring can be selectively hydrogenated. As the graphite, those having a surface area of 10 m ² / g or more and 400 m ² / g or less are used. The above reaction is generally performed at a pressure of 1 to 30 MPa and a temperature of 30 to 150 ° C. for 1 to 20 hours. After completion of the reaction, the catalyst is removed by filtration, and the catalyst is distilled off under reduced pressure until the ether-based organic solvent is substantially eliminated, thereby obtaining the target hydrogenated epoxy resin.

  Examples of the hydrogenated epoxy resin include “Likaresin HBE-100” (manufactured by Shin Nippon Chemical Co., Ltd., diglycidyl ether of alicyclic diol, epoxy equivalent 215, nonvolatile content 100%) and the like.

  The modified epoxy resin (E2) can be used alone or in combination of two or more. The modified epoxy resin (E2) is preferably contained in the main component of the anticorrosion coating composition according to the present invention in an amount of preferably 0 to 100 parts by weight (non-volatile content) based on 100 parts by weight (non-volatile content) of the epoxy resin (A). ), More preferably 0 to 50 parts by weight (non-volatile content), particularly preferably 0 to 30 parts by weight (non-volatile content).

<Other components that can be added to the curing agent component>
In addition to the amine curing agent (B), the curing agent component of the anticorrosion coating composition according to the present invention may optionally contain a curing accelerator that can contribute to adjustment of the curing speed, particularly acceleration. Examples of the curing accelerator include tertiary amines.

Examples of the curing accelerator include triethanolamine (N (C ₂ H ₅ OH) ₃ ), dialkylaminomethanol ({CH ₃ (CH ₂ ) _n } ₂ NCH ₂ OH, n: repetition number), and triethylene diamine (1 , 4-Diazacyclo (2,2,2) octane), 2,4,6-tri (dimethylaminomethyl) phenol (C ₆ H ₅ —CH ₂ N (CH ₃ ) ₂ , specifically, “Versamine EH30 ": Henkel Hakusui Co., Ltd .;" Ancamine K-54 ": Air Products Co., Ltd.). These curing accelerators are contained, if necessary, in an amount of 0.1 to 2.0 parts by weight (non-volatile content) based on 100 parts by weight (non-volatile content) of the anticorrosive coating composition of the present invention.

<Other ingredients>
The anticorrosive coating composition according to the present invention may further contain, if necessary, a pigment other than the flat pigment (D), a solvent, a silane coupling agent, a wetting and dispersing agent, Agents, anti-sagging / sedimentation inhibitors, inorganic dehydrating agents (stabilizers), antifouling agents and the like can be included as long as the object of the present invention is not impaired.

<Pigments other than flat pigment (D)>
The pigment is not particularly limited as long as it is other than the flat pigment (D), and those generally used in coating compositions can be used. For example, barium sulfate, potassium feldspar, barite powder, Extenders such as silica, calcium carbonate, and talc; and coloring pigments such as titanium white, red petal, yellow red petal, and carbon black. The above pigments can be used alone or in combination of two or more.

<Solvent>
The solvent is not particularly limited by its boiling point as long as it can dissolve the epoxy resin (A), and may be appropriately selected and used according to the coating workability of the anticorrosion coating composition according to the present invention. it can. Examples of the solvent include xylene, toluene, MIBK (methyl isobutyl ketone), 1-methoxy-2-propanol, MEK (methyl ethyl ketone), butyl acetate, n-butanol, iso-butanol, and IPA (isopropyl alcohol). These solvents can be used alone or in combination of two or more.

  In the present invention, the compounding amount of these solvents is not particularly limited, but from the viewpoint of adhesion to the wet surface of the deteriorated coating film, when an aromatic solvent such as xylene or toluene is used, the anticorrosive paint of the present invention is used. Preferably, it is contained in an amount of 0 to 20 parts by weight, more preferably 0 to 10 parts by weight, based on 100 parts by weight (nonvolatile content) of the composition.

<Silane coupling agent>
The silane coupling agent is not particularly limited, and a conventionally known silane coupling agent can be used. The silane coupling agent has at least two hydrolyzable groups in the same molecule, improves adhesion to a substrate, and improves coating viscosity. is preferably a compound capable of contributing to the reduction or the like, for example, the formula: X-SiMe n Y 3- n [n is 0 or 1, X is capable of reaction with the organic reactive group (e.g., amino groups, vinyl A group, an epoxy group, a mercapto group, a halogen group, a hydrocarbon group containing these groups, a group in which a bond between carbon atoms of the hydrocarbon group is replaced by an ether bond, etc.), and Me is A methyl group, and Y represents a hydrolyzable group (eg, methoxy group, ethoxy group). ] Is more preferable. Examples of such a silane coupling agent include “KBM403” (manufactured by Shin-Etsu Chemical Co., Ltd., γ-glycidoxypropyltrimethoxysilane).

  When the silane coupling agent is used, it is preferably 0.1 to 10 parts by weight (nonvolatile), more preferably 0.5 to 5 parts by weight, based on 100 parts by weight (nonvolatile) of the anticorrosive coating composition of the present invention. It is desirable to be contained in an amount of a part (nonvolatile content). When the silane coupling agent is used in such an amount in the anticorrosion coating composition according to the present invention, the coating performance such as adhesion of the obtained anticorrosion coating is improved. Lowering improves the workability of coating.

<Wet dispersant>
As the wetting and dispersing agent, those having a polyalkyl ether structure are preferable. For example, "Plysurf A208B" (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., polyoxyethylene lauryl ether phosphate, nonvolatile content 98%), " Plysurf A208F "(manufactured by Daiichi Kogyo Seiyaku Co., Ltd., polyoxyethylene alkyl (C8) ether phosphate). These wetting and dispersing agents can be used alone or in combination of two or more.

<Plasticizer>
The plasticizer is not particularly limited, and a conventionally known plasticizer can be used, and the flexibility and weather resistance of the obtained anticorrosion coating film can be improved. In particular, it is desirable to use a plasticizer having a reactive group from the viewpoint of improving the adhesion to a deteriorated coating film having a wet surface.

  Examples of the plasticizer include liquid hydrocarbon resins such as low-boiling fractions obtained by thermally decomposing naphtha which is liquid at ordinary temperature, and petroleum resins which are solid at ordinary temperature, xylene resins, cumarone indene resins and the like. Can be For example, a liquid hydrocarbon resin and a flexibility-imparting resin described in JP-A-2006-342360 are exemplified.

  Commercial products of the liquid hydrocarbon resin include “Nesileth EPX-L”, “Nesileth EPX-L2” (above, manufactured by NEVCIN, phenol-modified hydrocarbon resin), and “HILENOL PL-1000S” (manufactured by KOLON Chemical, Commercially available phenol-modified hydrocarbon resins) and petroleum resins include “Neopolymer E-100”, “Neopolymer K-2”, and “Neopolymer K3” (all of which are manufactured by Nippon Petrochemical Co., Ltd., C9 As commercially available products of Coumarone indene resin, “NOVARES CA 100” (manufactured by Rutgers Chemicals AG), and as commercial products of xylene resin, “Nicanol Y-51” (manufactured by Mitsubishi Gas Chemical Co., Ltd.) ) And the like.

<Use of anticorrosion coating composition according to the present invention>
Large steel structures such as ships, land structures, and bridges are coated with anticorrosion coatings for the purpose of preventing corrosion, but these coatings deteriorate over time, exposed to the outdoors, submerged, etc. , Requires regular repair painting. The anti-corrosion coating composition according to the present invention has an anti-corrosion coating composition on the surface of the deteriorated coating film without removing the deteriorated layer, and even on a wet surface having free moisture attached to the surface of the deteriorated coating film. A coating film having excellent properties and adhesion can be formed. Therefore, it depends on the structure, such as a ballast tank, in which it is difficult to completely dry the deteriorated coating surface, repair work in which it is difficult to take sufficient time to dry the deteriorated coating surface after washing with water, and the weather. It is suitable for application to a deteriorated coating film having a wet surface such as outdoor repair use.

When the anticorrosive coating composition according to the present invention is applied to the wet surface of the deteriorated coating film, if the amount of water adhered to the surface of the deteriorated coating film is 5 to 45 g / m ² , spray coating is suitable. When the amount of water adhering to the surface of the deteriorated coating film is more than 45 g / m ^2, coating with a brush, a roller, a spatula, or an iron is suitable. The anticorrosion coating composition according to the present invention can be coated even in water by selecting an appropriate coating method depending on the amount of moisture adhering to the surface of the deteriorated coating film. The film has good adhesion to the wet surface of the deteriorated coating.

  The conditions for the spray coating may be appropriately adjusted according to the thickness of the anticorrosion coating film to be formed. For airless spraying, for example, a primary (air) pressure: about 0.4 to 0.8 MPa, a secondary (paint) ) Pressure: about 10 to 26 MPa, and gun moving speed about 50 to 120 cm / sec.

  The thickness of the anticorrosion coating film according to the present invention is not particularly limited as long as it has a desired anticorrosion property, but is preferably 100 to 450 μm, more preferably 250 to 400 μm.

  When forming an anticorrosion coating film having such a film thickness, a single coating may be used to form an anticorrosion coating film having a desired thickness, or twice (or more if necessary) depending on the required anticorrosion properties. May be applied to form a corrosion-resistant coating film having a desired thickness. Since it is easy to form a more uniform coating film, it is preferable to form an anticorrosion coating film having a thickness in the above-mentioned range by applying twice (or more if necessary).

  The method for curing (drying) the anticorrosion coating film formed from the anticorrosion paint according to the present invention is not particularly limited, and it may be heated to about 50 to 60 ° C. in order to shorten the curing (drying) time. Usually, it is cured by leaving it at normal temperature and normal pressure for about 1 to 14 days.

  The method for producing a substrate with an anticorrosion coating according to the present invention includes a step of applying the anticorrosion coating composition to a substrate with a degraded coating or a wet surface thereof by an appropriate coating method, and the coated anticorrosion coating. Curing the coating composition under the conditions described above to form an anticorrosion coating.

  Further, depending on the desired use, a conventionally known overcoat paint such as an antifouling paint may be applied on the anticorrosion coating film of the base material having the anticorrosion coating film and cured.

  Hereinafter, the present invention will be described more specifically with reference to Examples, but the present invention is not limited thereto.

  Table 1 shows main materials used in Examples of the present invention.

[Example 1]
As shown in Table 2 below, 26 parts by weight of an epoxy resin “E-028” (Note 1), 5 parts by weight of a reactive diluent “Epodil 759” (Note 3), xylene 8. 3 parts by weight, n-butanol 3 parts by weight, MIBK (methyl isobutyl ketone) 2 parts by weight, silane coupling agent "KBM403" (Note 5) 1 part by weight, talc 25 parts by weight, mica "Szolite Mica 200-HK" (Note 6) 5 parts by weight, 16 parts by weight of potassium feldspar, 5 parts by weight of titanium white, and 1.5 parts by weight of an anti-sagging agent were added, glass beads were added thereto, and these components were mixed with a paint shaker. Then, the glass beads were removed, 2 parts by weight of water and a wetting and dispersing agent “Plysurf A208B” (Note 7). Add 2 parts by weight, disperse using a high-speed disperser at room temperature (23 ° C.) until uniform, then warm to 56 to 60 ° C., then cool to 30 ° C. or less to constitute the anticorrosive coating composition. A main component was prepared.

Further, as shown in Table 2 below, 4 parts by weight of polyoxyalkylene polyamine “Jeffamine D-230” (Note 8), 9 parts by weight of phenalkamine “Cardolite NX-4918” (Note 9), and tertiary amine “Ancamine K- 54 "(Note 15) 0.2 parts by weight of 1-methoxy-2-propanol and 0.8 parts by weight of 1-methoxy-2-propanol were mixed (at normal temperature and normal pressure) using a high-speed disperser to obtain an anticorrosive coating composition. The constituent hardener components were prepared.
The obtained main component and curing agent component were mixed before painting to prepare an anticorrosion coating composition.

[Examples 2 to 13 and Comparative Examples 1 to 6]
Each anticorrosion coating composition was prepared in the same manner as in Example 1 except that the components and the amounts contained in the main component and the curing agent component of Example 1 were changed as shown in Table 2 below.

Preparation of test plate with deteriorated coating film Tar epoxy resin paint (Blending composition: "jER 834" 2.9 parts by weight, "jER 1001" 6 parts by weight, "PA-66" (Otake Akira Shin Chemical Co., Ltd., polyamide 3.5 parts by weight of amine, active hydrogen equivalent 226, nonvolatile content 60%), 31 parts by weight of "HYTALON TC-77" (manufactured by SGS Chemical Co., Ltd., coal tar pitch), 36 parts by weight of talc, anti-sagging agent 3 parts by weight, 0.6 part by weight of tertiary amine "Ancamine K-54" (Note 15), 10.9 parts by weight of xylene, 2.8 parts by weight of toluene, 2.7 parts by weight of MIBK (methyl isobutyl ketone), MEK (Methyl ethyl ketone) 0.9 parts by weight, IPA (isopropyl alcohol) 0.7 parts by weight, n-butanol 0.7 parts by weight) were measured to have a size of 150 mm × 70 mm × 1.6 mm (thickness). Airless spray (primary (air) pressure: 0.6 MPa, secondary (air) pressure: 18 MPa) on a blasted steel plate (hereinafter also referred to as a “test plate”) so as to have a dry film thickness of 150 μm. And then dried in a room at a temperature of 23 ° C. and a humidity of 50% RH for 7 days, and then exposed outdoors for 30 days to an outdoor exposure test plate (A-a) and immersed in sea water at 40 ° C. for one year A test plate (A-b) was prepared.

  Further, instead of the tar epoxy resin paint, modified epoxy resin paint (composition composition: “E-028-90X” 16.5 parts by weight, “MAD-204 (A)” (Note 10) 8.1 parts by weight, 4.1 parts by weight of “PA-290 (A)” (Note 12), 8.7 parts by weight of “Neopolymer E-100”, 3.5 parts by weight of “HILENOL PL-1000S”, 20 parts by weight of talc, mica 5.2 parts by weight of Szolite Mica 200-HK "(Note 6), 13 parts by weight of potassium feldspar, 5.2 parts by weight of titanium white, 1.3 parts by weight of yellow petal, silane coupling agent" KBM403 "(Note 5) ) 0.9 parts by weight, 1.3 parts by weight of anti-sagging agent, 0.1 part by weight of tertiary amine "Ancamine K-54" (Note 15), 8.8 parts by weight of xylene, 1.7 parts by weight of n-butanol , 1-methoxy-2-propanol Except painted .6 parts by weight) was prepared outdoor exposure test plate in the same manner as described above and (B-a), the sea immersion test plate (B-b).

  Using the test plates (A-a), (A-b), (Ba), and (B-b) with the deteriorated coating film, the samples were obtained in Examples 1 to 13 and Comparative Examples 1 to 6. The following tests (1) to (6) were performed on the anticorrosion coating film formed from each anticorrosion coating composition. The results are shown in Table 3 below.

(1) Anticorrosion test on the base steel plate surface Each of the anticorrosion paint compositions shown in Table 2 was airless sprayed (primary (air) pressure: 0.1 μm) to a dry film thickness of about 250 μm. 6MPa, secondary (air) pressure: 18MPa), and coated with each anticorrosion coating film by drying for 7 days in an atmosphere of 23 ° C and 50% RH according to JIS K-5600 1-6. Was prepared, and the corrosion resistance was evaluated by the following salt water resistance test, salt water spray test, and high temperature / high humidity resistance test.

Salt water resistance test The test plate with each anticorrosion coating film prepared in the above (1) was immersed in salt water (salt concentration: 3%) at 40 ° C. for 180 days in accordance with JIS K-5600 6-1. The appearance of the film was visually evaluated according to the following criteria.

Salt spray test Each test plate with an anticorrosion coating film prepared in the above (1) was placed in a spray cabinet at 35 ± 2 ° C according to JIS K-5600 7-1, and salt water (salt concentration 5%) was continuously applied. The appearance of the anticorrosion coating after spraying for 180 days was visually evaluated according to the following criteria.

High-temperature and high-humidity test Each test plate with an anticorrosion coating film prepared in the above (1) was placed in a high-temperature and high-humidity tester having a temperature of 50 ± 1 ° C and a humidity of 95% or more in accordance with JIS K-5600 7-2. The appearance of the anticorrosion coating film after being held for 180 days was visually evaluated according to the following criteria.
(Evaluation criteria)
：: No blister, crack, rust, peeling, hue change.
Δ: Some defects (changes) are observed in any of blisters, cracks, rust, peeling, and hue.
×: A clear defect (change) is recognized in any of blisters, cracks, rust, peeling, and hue.

(2) Corrosion resistance test on dried deteriorated coating film Before applying the anticorrosion coating composition on the surface of the test plate with deteriorated coating film (A-b), the test plate with deteriorated coating film (A-b) Foreign substances such as salt and dust were removed from the surface by washing with water, dried at a temperature of 23 ° C. and a humidity of 50% for 1 hour, and it was visually confirmed that free moisture did not adhere to the surface of the deteriorated coating film. . Then, each anticorrosion paint composition shown in Table 2 was applied and dried in the same manner as in the above (1) to prepare each anticorrosion test plate, and in the same manner as in the above (1), a salt water resistance test and a salt spray were performed. The corrosion resistance was evaluated by a test and a high-temperature and high-humidity resistance test.

(3) Corrosion protection test on deteriorated coating film having wet surface 0.2 g (19 g / m2) of the surface of the test plate (Ab) with the deteriorated coating film immediately before the anticorrosion coating composition was applied. Water was sprayed by spraying so as to obtain ² ) and uniformly adhered, and it was visually confirmed that free moisture had adhered to the surface of the deteriorated coating film. Then, each anticorrosion paint composition shown in Table 2 was applied and dried in the same manner as in the above (1) to prepare each anticorrosion test plate, and in the same manner as in the above (1), a salt water resistance test and a salt spray were performed. The corrosion resistance was evaluated by a test and a high-temperature and high-humidity resistance test.

(4) Adhesion test of top coat on the surface of the dried deteriorated coating film The test plate with each deteriorated coating film of (A-a), (A-b), (Ba) and (B-b) was overcoated. Before painting, foreign substances such as salt and dust were removed by washing with water, and dried at a temperature of 23 ° C. and a humidity of 50% for 1 hour, and it was visually confirmed that free moisture did not adhere to the surface of the deteriorated coating film. . Subsequently, each of the anticorrosion paint compositions shown in Table 2 was applied and dried in the same manner as in the above (1) to prepare each overcoat adhesion test plate.

  Thereafter, each of the obtained top coat adhesion test plates was immersed in salt water (salt concentration: 3%) at 40 ° C. for 30 days, and the top coat adhesion was evaluated by the following method.

  As shown in FIG. 1, the surface of each of the above-mentioned top coat adhesion test plates (three-layer configuration of test plate / degraded coating film / anticorrosion coating film) had a cut of 4 cm on the surface of the test plate (corrosion protection coating 1). An X-shaped cut 2 intersecting at a degree was made at least to a depth reaching the surface of the deteriorated coating film. Then, a cellophane adhesive tape was attached to the site 3 where the X-shaped cut was made on the test plate, and one end of the tape was peeled off at an angle close to 90 ° with respect to the anticorrosion coating surface, whereby the deteriorated coating film / The state of peeling (peeling rate) between the anticorrosion coating films was evaluated. Here, the peeling rate was evaluated by visually observing the ratio of the area of the anticorrosion coating film peeled from the deteriorated coating film to the cut portion 3 and visually evaluating the overcoat adhesion between the deteriorated coating film and the anticorrosion coating film.

The anticorrosion coating composition according to the present invention can be used without any practical problems as long as the peeling rate between the deteriorated coating film and the anticorrosion coating film in the result of the overcoat adhesion test is 20% or less of the whole.
(Evaluation criteria)
：: No peeling was observed at all.
△: Less than 5% of the whole is peeled.
Δ: 5 to 20% of the whole is peeled off.
X: Exceeding 20% of the whole.

(5) Adhesion of Topcoat to Degraded Coating Surface Having Wet Surface (I) Test with each of the degraded coatings of (A-a), (A-b), (Ba) and (B-b) Immediately before the anticorrosive coating composition is applied to the board surface, water is sprayed by spraying so as to be 0.1 g (9.5 g / m ² ) and uniformly adhered thereto, and water released on the surface of the deteriorated coating film is sprayed. Was visually observed. Here, the deteriorated coating film surface in this state is referred to as “deteriorated coating film surface having a wet surface (I)”. Then, immediately (within 3 minutes after confirming the water content), each anticorrosion coating composition shown in Table 2 was applied and dried in the same manner as in the above (1) to obtain each overcoat adhesion test plate.
Thereafter, each of the obtained overcoat adhesion test plates was immersed in salt water (salt concentration: 3%) at 40 ° C. for 30 days, and the overcoat adhesion was evaluated in the same manner as in (4) above.

(6) Adhesion of Topcoat to Degraded Coating Surface Having Wet Surface (II) Test with each of the above degraded coatings of (A-a), (A-b), (Ba) and (B-b) Immediately before the anticorrosive coating composition is applied to the board surface, water is sprayed by spraying so that the amount becomes 0.2 g (19 g / m ² ), and the water is uniformly attached to the deteriorated coating film surface. Was visually confirmed. Here, the deteriorated coating film surface in this state is referred to as “deteriorated coating film surface having wet surface (II)”.
Thereafter, the top coat adhesion was evaluated in the same manner as in the above (5).

  As is evident from the test results in Table 3, by using a coating composition that satisfies the conditions specified in the present invention, not only on the surface of a deteriorated coating having a wet surface but also on the surface of a deteriorated coating having a wet surface, A coating film having excellent anticorrosion properties and good adhesion can be formed.

1: Anticorrosion coating 2: X-shaped cut 3: Site with cut

Claims (7)

A coating composition that can be applied to a wet surface of a substrate coated with a deteriorated coating film,
Epoxy resin (A),
At least one amine curing agent (B) selected from polyoxyalkylene polyamines, Mannich-modified amines and ketimines;
1 to 15 parts by weight of water (C) with respect to 100 parts by weight of the coating composition (non-volatile content);
A flat pigment (D),
Only including,
The anticorrosive coating composition, wherein the amine curing agent (B) contains at least a polyoxyalkylene polyamine .   The deteriorated coating film is formed by one kind of paint selected from tar epoxy resin paint, tar urethane resin paint, modified epoxy resin paint, modified urethane resin paint, epoxy resin paint, urethane resin paint, organic zinc paint and inorganic zinc paint. The anticorrosion paint composition according to claim 1, which is a coated film. It is characterized by containing at least 0.01 to 20 parts by weight (non-volatile content) of polyoxyalkylene polyamines as the amine curing agent (B) with respect to 100 parts by weight (non-volatile content) of the anticorrosive coating composition. The anticorrosion coating composition according to any one of claims 1 to 2 . The anticorrosion paint according to any one of claims 1 to 3 , further comprising at least one selected from the group consisting of a reactive diluent (E1) having an epoxy group and a modified epoxy resin (E2). Composition. An anticorrosion coating formed from the anticorrosion coating composition according to any one of claims 1 to 4 . A substrate with an anticorrosion coating formed by coating the surface of a substrate with a degraded coating with an anticorrosion coating formed from the anticorrosion coating composition according to any one of claims 1 to 4 . A step of coating the anticorrosion coating composition according to any one of claims 1 to 4 on the surface of the substrate with the deteriorated coating, and curing the coated anticorrosion coating composition to form an anticorrosion coating. A method for producing a substrate with an anticorrosion coating film, comprising:

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