JP2022145117A - Coating material and method for forming coated film - Google Patents

Abstract

To provide a coating material which enables formation of a coated film having thick dry film by single coating, and can satisfy usable life and curable time in a balanced manner, and a method for forming a coated film.SOLUTION: A coating material has a curing agent (A) and a main agent (B), wherein the curing agent (A) contains difunctional or trifunctional-or higher polyether amine (A1-1), alicyclic polyamine (A1-2) and (poly)amidoamine (A1-3), wherein the main agent (B) contains a bisphenol A type epoxy resin (B1) having a molecular weight of more than 400 and 4,000 or less, a low molecular weight epoxy compound (B2) having a molecular weight of 400 or less, and a reinforcement material (B3), and wherein the curing agent (A) and the main agent (B) are mixed so that the curing agent (A) falls within the range between 22 pts.mass or more and 35 pts.mass or less with respect to 100 pts.mass of the main agent (B).SELECTED DRAWING: None

Description

TECHNICAL FIELD The present invention relates to a paint used for anticorrosion of structures such as bridge piers, and a method for forming a coating film using this paint.

Road bridges and elevated roads need to be repainted periodically to prevent corrosion of bridge piers and other structures over time. Further, when the coating film formed by coating is locally peeled off, it is preferable to carry out repair coating without waiting for periodical recoating.

Here, when using a general epoxy resin-based paint, the repainting is performed several times (for example, about 6 times) in order to secure a coating film having the required film thickness after performing surface preparation. Needs to be overcoated. On the other hand, paints used for refinishing can only be recoated two or three times, but because of their short pot life, they are limited to repairing small areas of 10 m ² or less.

As a paint used in such repainting and repair painting, a paint that can be applied in a thick film that can reduce the number of times of recoating is desired. For example, in Patent Document 1, a coating composition that can be used for repainting and has a dry film thickness of 240 μm of a coating film obtained by one coating has a softening point of 50 ° C. to 50 ° C. by the ring and ball method. A main component comprising an epoxy resin at 170° C. and a coating film modifier, the content of the epoxy resin in the main component is 12 to 60% by mass, and the content of the coating film modifier is 2. A coating composition containing at least a main agent component and a curing agent component in a mass ratio of 70:30 to 92:8 is described. .

JP 2015-67762 A

In this regard, Patent Document 1 describes that a coating film having a dry film thickness of 240 μm can be formed by one coating.

However, although the coating composition described in Patent Document 1 is capable of forming a coating film with a thick dry film thickness by one coating, it is difficult to form a large-area coating film because of its short pot life. was unsuitable. Moreover, there is a problem that a paint with an excessively long pot life requires a considerable amount of time to harden. For this reason, there has been a demand for a paint that can satisfactorily satisfy both the usable time and the curing time in a well-balanced manner so as to shorten the curing time as much as possible while ensuring a certain usable time.

In addition, there has been a demand for a paint and a method for forming a coating film that can form a coating film having a dry film thickness as thick as possible with one coating and that can reduce the number of recoating as much as possible.

The object of the present invention is to form a paint and a paint film that can form a paint film with a large dry film thickness by one coating and that can satisfy the pot life and curing time in a well-balanced manner. to provide a method.

The present inventors have found that a curing agent (A) containing a difunctional or trifunctional or higher polyetheramine (A1-1), an alicyclic polyamine (A1-2) and a (poly)amidoamine (A1-3) , bisphenol A type epoxy resin (B1) and a low-molecular-weight epoxy compound (B2) is used in combination with the main agent (B), while facilitating curing, the pot life of the paint is extended, and workability is high. The present inventors have found that it is possible to form a coating film having a large film thickness with the above method, and have completed the present invention. More specifically, the present invention provides the following.

(1) The present invention provides a coating material having a curing agent (A) and a main agent (B), wherein the curing agent (A) is a polyetheramine (A1-1) having a functionality of 2, 3 or more, A bisphenol A type epoxy resin (B1 ), a low molecular weight epoxy compound (B2) having a molecular weight of 400 or less, and a reinforcing material (B3), and the curing agent (A) is 22 parts by mass with respect to 100 parts by mass of the main agent (B) 1 part or more and 35 parts by mass or less.

(2) The present invention also provides the paint according to (1) above, wherein the polyetheramine (A1-1) includes tri- or higher functional ones.

(3) The present invention also provides the paint according to (1) or (2) above, wherein the curing agent (A) further contains a non-reactive diluent (A2).

(4) The present invention also provides the paint according to (3) above, wherein the non-reactive diluent (A2) comprises a phenol-modified hydrocarbon resin.

(5) Further, in the present invention, the content of the polyetheramine (A1-1) in the curing agent (A) is in the range of 10% by mass or more and 40% by mass or less, and the modified polyamine (A1- The content of 2) is in the range of 10% by mass or more and 40% by mass or less, the content of the (poly)amidoamine (A1-3) is in the range of 10% by mass or more and 65% by mass or less, and the non- The paint according to (3) or (4) above, wherein the content of the reactive diluent (A2) is 40% by mass or less.

(6) Further, the present invention is the paint according to any one of (1) to (5) above, wherein the reinforcing material (B3) contains silica and alumina.

(7) Further, in the present invention, the content of the bisphenol A type epoxy resin (B1) in the main agent (B) is in the range of 15% by mass or more and 35% by mass or less, and the low molecular weight epoxy compound (B2 ) is in the range of 35% by mass to 55% by mass, and the content of the reinforcing material (B3) is in the range of 20% by mass to 50% by mass. ) is the paint according to any one of the above.

(8) In addition, the present invention provides a polyetheramine (A1-1) having a functionality of 2 or 3 or more, a modified polyamine (A1-2) containing a modified alicyclic polyamine, and a (poly)amidoamine (A1- 3) a curing agent (A) containing , a bisphenol A type epoxy resin (B1) having a molecular weight in the range of more than 400 to 4000 or less, a low molecular weight epoxy compound (B2) having a molecular weight of 400 or less, and a reinforcing material The main agent (B) containing (B3) is mixed so that the curing agent (A) is in the range of 22 parts by mass or more and 35 parts by mass or less with respect to 100 parts by mass of the main agent (B). 1. A method of forming a coating film, comprising a mixing step of preparing a coating material, and a coating and curing step of applying the coating material to the surface of a substrate and then drying the coating material to form a cured coating film.

(9) Further, the present invention is the method of forming a coating film according to (8) above, wherein in the coating/curing step, the coating material is applied to the surface of the base material using a roller.

According to the present invention, it is possible to form a coating film with a large dry film thickness by one coating, and to form a coating and a coating film that can satisfy the pot life and curing time in a well-balanced manner. can provide a method.

Specific embodiments of the present invention will be described in detail below. In addition, the present invention is not limited to the following embodiments, and various modifications are possible without changing the gist of the present invention.

The paint according to this embodiment contains a curing agent (A) and a main agent (B). Here, the curing agent (A) includes a polyetheramine (A1-1) having a functionality of two or more, a modified polyamine (A1-2) containing a modified alicyclic polyamine, and a (poly)amidoamine (A1 -3). Further, the main agent (B) comprises a bisphenol A type epoxy resin (B1) having a molecular weight in the range of more than 400 to 4000 or less, a low molecular weight epoxy compound (B2) having a molecular weight of 400 or less, and a reinforcing material (B3). and In addition, the paint according to the present embodiment is obtained by mixing the curing agent (A) with 100 parts by mass of the main agent (B) so as to be in the range of 22 parts by mass or more and 35 parts by mass or less.

By using the coating material according to the present embodiment, it is possible to extend the pot life while facilitating curing, and to form a coating film having a large thickness with high workability. Therefore, the present invention provides a paint that can form a paint film having a large dry film thickness in one application and that satisfies both the pot life and the curing time in a well-balanced manner, and a method for forming the paint film. be able to.

<Curing agent>
The curing agent (A) contained in the paint according to the present embodiment includes a polyetheramine (A1-1) that is bifunctional or trifunctional or more, a modified polyamine (A1-2) containing a modified alicyclic polyamine, (Poly) amidoamine (A1-3).

The coating material according to the present embodiment uses polyetheramine (A1-1), modified polyamine (A1-2) and (poly)amidoamine (A1-3) as the curing agent (A) in combination, so that it can be cured at low temperatures such as in winter. Curing can be facilitated by the reaction with the main agent (B) even under environmental conditions, and the progress of curing due to the reaction with the main agent (B) can be moderately slowed to extend the pot life of the paint. In addition, the toughness of the coating film obtained by the reaction with the main agent (B) can be enhanced.

[Polyetheramine (A1-1)]
Polyetheramine (A1-1) is a polyoxyalkyleneamine and is a compound containing a primary amino group at the end of a polyether skeleton. The present invention contains a polyetheramine (A1-1) having a functionality of two or more than three. As a result, the amino group at the end of the polyether skeleton reacts with the epoxy group contained in the bisphenol A type epoxy resin (B1) or the low-molecular-weight epoxy compound (B2), thereby forming a chain molecule. Therefore, flexibility can be imparted to the resulting coating film. In addition, since the curing agent (A) contains the polyetheramine (A1-1), the reaction between the amino group and the epoxy group is moderately inhibited by the polyether chain of the polyetheramine (A1-1). The progress of curing due to the reaction with the main agent (B) can be moderated, and as a result, the usable life of the paint can be extended.

The polyetheramine (A1-1) contains bifunctional or trifunctional or more, and may contain tri or more functional. That is, the number of terminal amino groups of the polyether skeleton is 2 or more per molecule, but may be 3 or more.

The polyether skeleton of polyetheramine (A1-1) may be any alkylene oxide, but is preferably propylene oxide (PO), ethylene oxide (EO) or mixed EO/PO.

Examples of polyetheramine (A1-1) include poly(oxypropylene)triamine, poly(oxypropylene)diamine, poly(oxyethylene)triamine, and poly(oxyethylene)diamine. Among them, polyetheramine (A1- 1) is preferably poly(oxypropylene)triamine or poly(oxyethylene)triamine, more preferably poly(oxypropylene)triamine.

The amine value of the polyetheramine (A1-1) is preferably in the range of 100 mgKOH/g to 700 mgKOH/g, more preferably in the range of 200 mgKOH/g to 500 mgKOH/g.

The molecular weight of the polyetheramine (A1-1) is preferably in the range of 100-2000, more preferably in the range of 200-1000. Here, the polyetheramine (A1-1) may be one or a mixture of two or more of these compounds, in which case the compounds constituting the mixture polyetheramine (A1-1) is preferably within the above range.

The mixing ratio of the polyetheramine (A1-1) is preferably 10% by mass, more preferably 15% by mass, based on the total mass of the curing agent (A). The (poly)amidoamine (A1-3) content is preferably 40% by mass or less, more preferably 30% by mass or less, relative to the total mass of the curing agent (A).

[Alicyclic polyamine (A1-2)]
The alicyclic polyamine (A1-2) is composed of a modified or unmodified alicyclic polyamine. The alicyclic polyamine is a polyamine having a cyclic aliphatic hydrocarbon in its molecule, and preferably has a 4- to 8-membered cyclic aliphatic hydrocarbon in its molecule. In the alicyclic polyamine, some of the carbon atoms constituting the cyclic aliphatic hydrocarbon in the molecule may be heteroatoms such as nitrogen atoms. have. By including the alicyclic polyamine (A1-2), the reactivity with the epoxy groups contained in the bisphenol A type epoxy resin (B1) and the low molecular weight epoxy compound (B2) can be increased to shorten the curing time. . At the same time, the steric hindrance of the cycloaliphatic hydrocarbon can moderate the curing reaction, so that the pot life of the paint can be extended.

Alicyclic polyamines include, by way of example, alicyclic diamines and alicyclic triamines. More specifically, 1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane, 4,4′-(4-amino-1,3-phenylenebismethylene)bis(cyclohexylamine ), 1,3-cyclopentanediamine, 1,4-cyclohexanediamine, 1,3-cyclohexanediamine, 1-amino-3-aminomethyl-3,5,5-trimethylcyclohexane, 1-amino-1-methyl- 4-aminomethylcyclohexane, 1-amino-1-methyl-3-aminomethylcyclohexane, 4,4′-methylenebis(cyclohexylamine), 4,4′-methylenebis(3-methyl-cyclohexylamine), methyl-2, 3-cyclohexanediamine, methyl-2,4-cyclohexanediamine, methyl-2,6-cyclohexanediamine, isophoronediamine, norbornanediamine {for example, 2,5-bis(aminomethyl)bicyclo[2.2.1]heptane, 2,6-bis(aminomethyl)bicyclo[2.2.1]heptane, etc.} and the like.

Here, the alicyclic polyamine (A1-2) may contain a modified alicyclic polyamine. Since the alicyclic polyamine is modified, it contributes to the reaction between the amino group and the epoxy group, and in a low temperature environment such as winter, more specifically in an environment of 5 ° C. to 10 ° C., the amino group can facilitate curing due to the reaction between and the epoxy group.

Modified alicyclic polyamines include Mannich compounds, amine adducts with epoxy compounds (epoxy adducts of polyamines), ketimine compounds, polyamidoamines, Michael addition compounds, aldimine compounds, urea adducts with isocyanate compounds, and the like. can be done. Among them, an example of the Mannich compound is a reaction product of a primary or secondary amine and formaldehyde. Among them, a reaction product of aniline and formaldehyde capable of forming a heterocyclic ring is preferable. . Mannich compounds also include products of further reactions on Mannich compounds, such as products of hydrogenation reactions.

As the alicyclic polyamine (A1-2), one or a combination of two or more of these compounds can be used.

The mixing ratio of the alicyclic polyamine (A1-2) is preferably 10% by mass, more preferably 15% by mass, relative to the total mass of the curing agent (A). Also, the mixing ratio of the alicyclic polyamine (A1-2) is preferably 40% by mass or less, more preferably 30% by mass or less, relative to the total mass of the curing agent (A).

The curing agent (A) may contain polyamines other than alicyclic polyamines. For example, chain aliphatic polyamines such as diethylenetriamine and triethylenetetramine and modified products thereof, aromatic ring-containing aliphatic polyamines such as metaxylenediamine and modified products thereof, and metaphenylenediamine, diaminodiphenylmethane, diaminodiphenylsulfone, etc. Examples include, but are not limited to, aromatic polyamines and modified products thereof.

[(Poly) amidoamine (A1-3)]
The (poly)amidoamine (A1-3) is a compound having single or multiple amide bonds and amino groups in the molecule, and has reactive primary and secondary amines in the molecule. By using such a (poly)amidoamine (A1-3), the toughness of the coating film is increased, and the progress of curing due to the reaction with the main agent (B) is slowed down, so the pot life of the coating is extended. be able to. In addition, "(poly)amidoamine" in this specification includes one or both of amidoamine and polyamidoamine.

The amine value of the (poly)amidoamine (A1-3) is preferably in the range of 200 mgKOH/g or more and 800 mgKOH/g or less, more preferably in the range of 350 mgKOH/g or more and 500 mgKOH/g or less. As a result, the (poly)amidoamine (A1-3) contains an appropriate amount of carbon atoms in its molecule, so that the toughness of the coating film obtained by curing with the main agent (B) can be further enhanced.

The mixing ratio of (poly)amidoamine (A1-3) is preferably 10% by mass, more preferably 20% by mass, based on the total mass of curing agent (A). The (poly)amidoamine (A1-3) content is preferably 65% by mass or less, more preferably 55% by mass or less, relative to the total mass of the curing agent (A).

The curing agent (A) may contain amines not included in the polyetheramine (A1-1), modified polyamine (A1-2) and (poly)amidoamine (A1-3). However, the mixing ratio of amines not contained in polyetheramine (A1-1), modified polyamine (A1-2) and (poly)amidoamine (A1-3) is , is preferably 10% by mass or less, more preferably 5% by mass or less.

[Non-reactive diluent (A2)]
The non-reactive diluent (A2) adjusts physical properties such as viscosity in the mixture of the curing agent (A) and the main agent (B), thereby mixing the curing agent (A) and the main agent (B) and painting operations. It can be arbitrarily contained in the curing agent (A) for the purpose of improving the properties and increasing the flexibility of the coating film. As specific examples of the non-reactive diluent (A2), it is preferable to use those that are liquid at room temperature, and hydrocarbon resins such as xylene resins and coumarone-indene resins, modified products thereof, benzyl alcohol, phenol, and phenethyl alcohol. , nonylphenol, dinonylphenol, isoparaffin mixtures, high-boiling aromatic hydrocarbon compounds, white tar, etc., but are not limited thereto.

Among these, as the non-reactive diluent (A2), a liquid phenol-modified hydrocarbon resin is preferably used from the viewpoint of enhancing the water resistance of the coating film. Examples of phenol-modified hydrocarbon resins include those obtained by copolymerizing diolefins and monoolefins contained in cracked oil fractions of petroleum with phenols such as phenol, cresol and xylenol.

Commercially available hydrocarbon resins and modified products thereof contained in the non-reactive diluent (A2) include "EPX-L, EPX-L2" (manufactured by NEVCIN / phenol-modified hydrocarbon resin ), “Nikanol (R) Y-51” (manufactured by Mitsubishi Gas Chemical Co., Ltd./xylene resin), and the like.

When the non-reactive diluent (A2) is blended, the blending ratio of the non-reactive diluent (A2) is preferably 5% by mass, more preferably 10% by mass, relative to the total mass of the curing agent (A). . In addition, the blending ratio of the non-reactive diluent (A2) is relative to the total mass of the curing agent (A), from the viewpoint of relatively increasing the content of components that contribute to the reaction and thereby enhancing the coating curability. 40% by mass or less is preferable, 30% by mass or less is more preferable, and 25% by mass or less is even more preferable.

[Other ingredients]
The curing agent (A) according to the present embodiment includes, if necessary, a plasticizer, a moisture absorbent, a physical property modifier, a coloring agent, an anti-sagging agent, an antioxidant, an anti-aging agent, a solvent, a pigment, a dye, Various additives such as phosphors may be added.

<Main agent>
The main agent (B) contained in the paint according to this embodiment contains a bisphenol A type epoxy resin (B1), a low molecular weight epoxy compound (B2), and a reinforcing material (B3).

In the paint according to the present embodiment, by adding a low-molecular-weight epoxy compound (B2) to the bisphenol A type epoxy resin (B1) as the main agent (B), the viscosity of the paint is moderately lowered, thereby improving the coating workability. The pot life of the paint can be extended by increasing the molecular weight and slowing down the increase in molecular weight due to the reaction with the curing agent (A). In addition, by adding the reinforcing material (B3) to the base material (B), even if a coating film having a large film thickness is formed in a single application of the coating material to the base material, the coating material can be prevented from dripping from the coating film. can be done. Therefore, by using the main agent (B) of the present embodiment, it is possible to obtain a coating material that is suitable for forming a coating film having a large thickness, has high coating workability, and has a long usable life.

[Bisphenol A type epoxy resin (B1)]
Bisphenol A type epoxy resin (B1) is an epoxy resin obtained by a condensation reaction of bisphenol A and epichlorohydrin, has two or more epoxy groups in one molecule, and reacts with an amine-based curing agent to crosslink. is a polymer or oligomer capable of By using the bisphenol A type epoxy resin (B1), it is possible to accelerate the curing of the paint and to obtain a coating film with high toughness by curing.

The weight average molecular weight of the bisphenol A type epoxy resin (B1) is preferably in the range of more than 400 to 4000 or less, more preferably in the range of more than 400 to 1000 or less. Also, the viscosity (25° C.) of the bisphenol A type epoxy resin (B1) is preferably 20 Pa·s or less, more preferably 15 Pa·s or less. The epoxy equivalent of the bisphenol A type epoxy resin (B1) (according to JIS K7236) is preferably 150 g/eq to 1000 g/eq, more preferably 150 g/eq to 700 g/eq.

The mixing ratio of the bisphenol A type epoxy resin (B1) is preferably 15% by mass or more, more preferably 20% by mass or more, relative to the total mass of the main agent (B). The proportion of the bisphenol A epoxy resin (B1) to be mixed may be preferably 35% by mass or less, more preferably 30% by mass or less, relative to the total mass of the main agent (B).

[Low molecular weight epoxy compound (B2)]
The low-molecular-weight epoxy compound (B2) is a compound having an epoxy group and having a molecular weight in the range of 400 or less. More preferably, it is a compound that has two or more epoxy groups in one molecule and can be crosslinked by reacting with an amine-based curing agent. By combining such a low-molecular-weight epoxy compound (B2) with the bisphenol A epoxy resin (B1), the viscosity of the paint is moderately reduced compared to the case where only the bisphenol A epoxy resin (B1) is used. Therefore, the coating workability can be improved. In addition, by reducing the average molecular weight of the epoxy compound, it is possible to moderate the increase in molecular weight due to the reaction with the curing agent (A) without losing reactivity, so the pot life of the paint is extended. be able to.

The low-molecular-weight epoxy compound (B2) is not particularly limited as long as it is a commercially available mono-, di-, or tri-epoxide. For example, neopentyl glycol diglycidyl ether, o-cresyl glycidyl ether, trimethylolpropane triglycidyl ether, phenyl glycidyl ether, alkyl glycidyl ether, glycidyl ester, α-olefin epoxide, 1,6-hexanediol diglycidyl ether, cyclohexane At least one selected from dimethanol glycidyl ether, cyclohexanedimethanol diglycidyl ether, alkylphenyl glycidyl ether, and alkylphenol glycidyl ether can be used as the low molecular weight epoxy compound (B2).

The blending ratio of the low-molecular-weight epoxy compound (B2) is preferably 35% by mass or more, more preferably 40% by mass or more, relative to the total mass of the main agent (B). In addition, the blending ratio of the low-molecular-weight epoxy compound (B2) is preferably 55% by mass or less, more preferably 50% by mass or less, relative to the total mass of the main agent (B), from the viewpoint of facilitating the formation of a thick coating film. may be

[Reinforcing material (B3)]
The paint of the present invention contains a reinforcing material (B3). As a result, even if a coating film having a large film thickness is formed in one application of the coating material to the base material, the coating material can be prevented from dripping from the coating film.

The reinforcing material (B3) may contain inorganic oxides such as silica, alumina, zirconia and yttria, as well as fine ceramics such as silicon nitride and silicon carbide. Among these, it is particularly preferable to contain an inorganic oxide, and it is more preferable to contain at least one of silica and alumina, from the viewpoint of availability of the material.

The content of the reinforcing material (B3) is preferably 20% by mass or more, more preferably 25% by mass or more, relative to the total mass of the main agent (B), from the viewpoint of preventing the paint from dripping from the coating film. On the other hand, the blending ratio of the reinforcing material (B3) is preferably 50% by mass or less, more preferably 45% by mass or less, relative to the total mass of the main agent (B), from the viewpoint of facilitating application to the substrate. may be

Among the reinforcing materials (B3), it is preferable to contain silica (B3-1) and alumina (B3-2).

(Silica (B3-1))
Among these, the silica (B3-1) has a specific surface area by the BET method of preferably 25 m ² /g or more and 330 m ² /g or less, more preferably 50 m ² /g or more and 150 m ² /g or less. one can be used. In addition, the particle size of silica (B3-1) is set within a range not exceeding the required thickness of the coating film. Furthermore, the surface of silica (B3-1) may be subjected to hydrophobic treatment or hydrophilic treatment as necessary.

The content of silica (B3-1) in the paint of the present invention may be 1% by mass or more with respect to the total mass of the main component (B). On the other hand, the content of silica (B3-1) in the paint of the present invention may be preferably 15% by mass or less, more preferably 10% by mass or less, relative to the total mass of the main ingredient (B).

(Alumina (B3-2))
On the other hand, the alumina (B3-2) preferably has a peak in the range of more than 63 μm to 1700 μm or less, more preferably more than 75 μm to 1000 μm or less in the mass-based particle size distribution. By using alumina (B3-2) having such a particle size distribution, when a coating is applied to a base material to form a coating film, it is possible to prevent the coating from dripping from the coating film.

The content of alumina (B3-2) in the paint of the present invention is preferably 20% by mass or more, more preferably 25% by mass or more, relative to the total mass of the main agent (B). On the other hand, the content of alumina (B3-2) in the paint of the present invention may be preferably 40% by mass or less, more preferably 35% by mass or less, relative to the total mass of the main component (B).

[Other components (B4)]
The main agent (B) used in the present embodiment contains a non-reactive diluent, a silane coupling agent, an organic solvent, a plasticizer, etc. as other components (B4) for the purpose of improving workability. may

In addition, the main agent (B) used in the present embodiment may contain a colorant such as a pigment, a dye, or a phosphor as another component (B4) for the purpose of enhancing the decorativeness of the coating film. . Colorants include carbon black, titanium dioxide, ferric oxide, active zinc white, black iron oxide, yellow iron oxide, zinc ferrite and cobalt aluminum oxide.

The content of the other component (B4) in the paint of the present invention may be preferably 15% by mass or less, more preferably 10% by mass or less, relative to the total mass of the main component (B).

<Method for Forming Coating Film>
The method of forming a coating film according to the present embodiment includes a mixing step of mixing the curing agent (A) and the main agent (B) described above to prepare a coating, and drying the coating after applying the coating to the surface of the base material. and a coating and curing step of forming a coating cured by.

[Mixing process]
In the mixing step, the curing agent (A) and the main agent (B) are mixed to produce a paint. That is, curing containing a polyetheramine (A1-1) having a functionality of 2 or 3 or more, a modified polyamine (A1-2) containing a modified alicyclic polyamine, and a (poly)amidoamine (A1-3) agent (A), a bisphenol A type epoxy resin (B1) having a molecular weight in the range of more than 400 to 4000 or less, a low molecular weight epoxy compound (B2) having a molecular weight of 400 or less, and a reinforcing material (B3) Mix with the main agent (B). The curing agent (A) described above is often liquid, and the main agent (B) is paste. Therefore, as a mixing means, it is preferable to use a means capable of mixing the liquid curing agent (A) with the paste-like main agent (B).

The mixing ratio of the curing agent (A) and the main agent (B) is such that the curing agent (A) is 22 parts by mass or more and 35 parts by mass or less, more preferably 25 parts by mass or more and 30 parts by mass, per 100 parts by mass of the main agent (B). Mix so that it becomes a part or less. By setting the mixing ratio of the curing agent (A) and the main agent (B) within this range, the workability when applying the coating material to the substrate to form a coating film is improved, and in the coating and curing process described later. Curing of the coating film can be accelerated. In particular, the curing agent (A) and the main agent (B) are obtained by mixing 22 parts by mass or more, more preferably 25 parts by mass or more, of the curing agent (A) with respect to 100 parts by mass of the main agent (B). It is also possible to increase the toughness of the coating film.

The mixing time of the curing agent (A) and the main agent (B) in the mixing step is preferably 1 minute or longer, more preferably 2 minutes or longer, in order to obtain a homogeneous paint. On the other hand, although the upper limit of the mixing time can be determined according to the pot life, it is preferably less than 10 minutes, more preferably 5 minutes or less. The term "pot life" as used herein refers to the time when the paint can no longer be spread with a brush when the paint is stored in a container with a volume of 300 cm ³ based on the method of determining by hand application in JISK6870:2008.

The pot life of the paint varies depending on environmental conditions such as the temperature of use, but it is preferably longer than 70 minutes, more preferably 75 minutes or longer. As a result, even when the area of the portion to be coated with the paint is large, the coating can be applied without being cured in the coating/curing step described later.

[Coating/curing process]
In the coating and curing step, a coating comprising a mixture of a curing agent (A) and a main agent (B) is applied to a substrate to form a coating film, and then the coating film is dried to form a cured coating film. .

The base material to which the paint is applied is not particularly limited, and it is also preferable to apply the paint to a material at least part of the surface of which is made of steel. The paint of the present invention can be strongly bonded to the base material and can form a thick coating film. can be given.

The substrate may be subjected to surface conditioning as necessary. Even when the paint of the present invention is applied to a substrate that has undergone only a relatively light surface preparation (surface preparation to the extent of removing rusted parts) such as tertiary keren, the coating with the desired characteristics can be obtained. It is possible to obtain membranes.

Conventionally known means such as a brush or a roller can be used as means for applying the coating material to the base material. The paint of the present invention has a viscosity that can withstand application to the substrate surface using a roller in the coating and curing process, and has a long pot life, so it can be applied to a wide range of substrates. can be formed at once.

The thickness of the coating applied to the substrate can be, for example, 200 μm to 1000 μm, more preferably 250 μm to 500 μm. In the paint of the present invention, the coating film is formed by curing the epoxy resin (B1) and the low-molecular-weight epoxy compound (B2), and the coating film is reinforced by including the reinforcing material (B3). Even if a coating film having a dry film thickness of 200 μm to 1000 μm is formed by coating, dripping of the coating material is less likely to occur. Therefore, by using the coating material of the present embodiment, a coating film having a large thickness can be efficiently formed.

The time required for drying and curing the coating film varies depending on environmental conditions such as the temperature of use, but is preferably 24 hours or less under normal temperature conditions (10° C. or higher and 25° C. or lower). As a result, the work of repeatedly coating the base material with the coating material can be performed every day, so that a coating film having a desired thickness can be efficiently formed by multiple coatings.

As described above, the paint of the present invention has a long pot life and can be applied to a wide range of substrates, and can form a large dry film with a single coating. It can be suitably used for painted surfaces of outdoor structures having an area in the range of 10 m ² to 500 m ² , especially painted surfaces that require recoating. In addition, the paint of the present invention can also be suitably used for repair coating of larger painted surfaces of structures such as road bridges and bridge piers of elevated roads.

Next, examples of the present invention will be described in order to further clarify the effects of the present invention, but the present invention is not limited to these.

<Preparation of paint>
After preparing the curing agent (A) and the main agent (B) at the mixing ratios shown in Table 1, the curing agent (A) and the main agent (B) were mixed to obtain a paint.

The details of each component used in the preparation of the curing agent (A) and main agent (B) shown in Table 1 are as follows.

[Curing agent (A)]
(Polyetheramine (A1-1))
- Poly(oxypropylene) diamine (manufactured by Huntsman Corporation, model number: Jeffamine D-400, molecular weight: 430, amine value: 230 mgKOH/g to 263 mgKOH/g)
・Trimethylolpropane poly(oxypropylene) triamine (manufactured by Huntsman Corporation, model number: Jeffamine T-403, molecular weight: 440, amine value: 342 mgKOH/g to 370 mgKOH/g)
(Alicyclic polyamine (A1-2))
・Hydrogenation reaction product of aniline and formaldehyde (4,4′-(4-amino-1,3-phenylenebismethylene)bis(cyclohexylamine)) (manufactured by Chori GLEX Co., Ltd., model number: Ancamine 2280, content of the hydrogenation reaction product: 40% by mass to 50% by mass, amine value: 250 mgKOH/g)
Epoxy adduct of 1,3-bis(aminomethyl)cyclohexane (manufactured by Chori GLEX Co., Ltd., model number: hardener PH834, content of the epoxy adduct: 15% by mass, amine value: 300 mgKOH/g to 380 mgKOH/g)
A mixture of 1,3-bis(aminomethyl)cyclohexane, meta-xylenediamine, and 4-tert-butylphenol (manufactured by Yun Teh Industries, model number: JOINTMINE989, 1,3-bis(aminomethyl)cyclohexane content: 40 % to 50% by mass, meta-xylenediamine content: 7% by mass, amine value: 380 mgKOH/g)
・Modified aliphatic polyamine (manufactured by Chori GLEX Co., Ltd., model number: hardener PH785, containing polyoxypropylene diamine, amine value: 320 mgKOH/g)
((poly)amidoamine (A1-3))
Polyamidoamine (manufactured by Tsuno Foods Industry Co., Ltd., model number: Vegichem Green V140, amine value: 370 mgKOH / g to 400 mgKOH / g, polyamidoamine content: 95% by mass)
Polyamidoamine (manufactured by Yun Teh Industries, model number: JOINTMINE320, amine value: 370 mgKOH/g to 430 mgKOH/g, polyamidoamine content: 90% by mass)
Amidoamine (manufactured by Yun Teh Industries, model number: JOINTMINE3599, amine value: 440 mgKOH/g, amidoamine content: 95% by mass)
[Non-reactive diluent (A2)]
・ NEVOXY (registered trademark) EPX-L2 (manufactured by Neville Chemical)

[Main agent (B)]
[Bisphenol A type epoxy resin (B1)]
- Bisphenol A type epoxy resin (molecular weight: more than 400 to 1000 or less, epoxy equivalent: 150 g/eq to 700 g/eq, viscosity: 15 Pa s or less/25°C)
[Low molecular weight epoxy compound (B2)]
- Trimethylolpropane triglycidyl ether (manufactured by Huntsman Advanced Materials, model number: ERISYS (registered trademark) GE-30, molecular weight: 302, epoxy equivalent: 135 g/eq to 150 g/eq, viscosity: 100 cps to 200 cps/25°C)
[Reinforcing material (B3)]
(Silica (B3-1))
・Hydrophobic fumed silica (manufactured by Nippon Aerosil Co., Ltd., model number: RY-200S, specific surface area by BET method: 65 m ² /g to 95 m ² /g)
(Alumina (B3-2))
・Alumina (with a mass-based particle size distribution peak in the range of more than 75 μm and 1000 μm or less)

The obtained coating material is applied to a base material made of a plate material with a flat surface using a roller to form a coating film with a uniform thickness of 300 μm, and then left to stand to obtain a coating film. rice field.

At this time, regarding the workability of the paint and whether or not it is possible to obtain a thick coating film with a single coating, the presence or absence of stickiness when applying the paint to the substrate, and the dripping of the paint from the coating film. The presence or absence was evaluated visually. A paint that can maintain its shape when applied to a substrate with a thickness of 300 μm (no sagging) and that is easy to spread when applied, has good workability, and dries in one coat. It was evaluated as "○" because it is possible to obtain a coating film having a large film thickness. In addition, if the paint is difficult to maintain its shape when applied to the substrate (sagging) or difficult to spread when applied, workability is poor or the dry film thickness is thick in one coat. It was set as "x" because it was difficult to obtain a film (impossible). Table 1 shows the results.

In addition, regarding the usable life of the paint, based on the method of determining by hand painting in JISK6870: 2008, when the paint was stored in a container with a volume of 300 cm ³ , the usable time was defined as the time when the paint could not be spread using a brush. . Table 1 shows the measurement results of the pot life. At this time, those with a pot life of more than 70 minutes were regarded as having a long pot life, and the pot life was evaluated as “◯”. In addition, those with a pot life of 70 minutes or less were regarded as having a short pot life (impossible), and the pot life was evaluated as “x”. Table 1 shows the results.

In addition, the curing of the coating film during drying and curing was evaluated based on JIS K 5600-1-1:1999. Here, when the paint is applied to the base material (test plate) in one coat and dried at room temperature (dried at 23°C ± 2°C), the state of curing and drying within 24 hours (the center of the coated surface and the index finger, the paint surface will not be dented due to fingerprints, and the movement of the paint film will not be felt. state), the coating film curing was evaluated as "good". On the other hand, when the paint is applied to the substrate in one coat and dried at room temperature, if it does not reach a state of curing and drying within 24 hours, the curing of the coating film is considered to be unsatisfactory (improper). The evaluation of coating film curing was set to "x". In addition, after applying the paint to the base material in one coat, dry to the touch (lightly touch the center of the coated surface with your fingertips so that your fingertips do not get dirty), semi-hard dry (gently touch the center of the coated surface with your fingertips, etc.). The surface was lightly rubbed to remove any traces) and the time required for curing and drying was measured. Table 1 shows the results.

In addition, regarding the toughness of the coating film, a coating film having a dry thickness of 500 μm was formed on a base material made of polypropylene, and after sufficient curing, the coating film was peeled off, and the obtained coating film was bent 180° with a finger. The state of the coating film when folded (folded in two) was evaluated. At this time, if the coating film did not crack and was deformed in the direction of returning to the original shape when the bending force was released, it was evaluated as having high toughness and was given "◯". In addition, when the coating film was broken at 180 ° with a finger, or when the bending force was released, the one that did not deform in the direction of returning to the original state was evaluated as having low toughness (impossible). " Table 1 shows the results.

Of the three evaluation results related to the workability of the paint, whether it is possible to obtain a thick dry film with a single coating, the usable life of the paint, and the curing of the paint film, all three were evaluated as "○". In the case where it was applied, it was possible to obtain a thick coating film by one coating, and it was evaluated as "Good" because the pot life and the curing time were well balanced. In addition, if any one of these three evaluation results is "x", it means that it is difficult to obtain a thick coating film with a single coating, or that the pot life and curing time are insufficient. The balance was evaluated as "x" as unsatisfactory. Table 1 shows the results.

From the evaluation results in Table 1, the paints of Examples 1 to 7 of the present invention have the composition of the curing agent (A) and the main agent (B) within the appropriate range of the present invention, and the workability of the paint and the The evaluation results regarding whether or not it is possible to obtain a coating film with a thick dry film thickness, the evaluation results regarding the usable life of the paint, and the evaluation results regarding the coating film curing were all evaluated as "○", and in the overall evaluation as well. It was evaluated as "0".

From the above results, the paints of Examples 1 to 7 of the present invention can obtain a coating film with a large dry film thickness by one coating, and the pot life (over 70 minutes) and curing time (24 minutes after coating) time) and satisfaction in a well-balanced manner.

Furthermore, the paints of Examples 1 to 7 of the present invention were evaluated as "good" in terms of the toughness of the coating film, and it was found that a coating film having excellent toughness was obtained.

On the other hand, the paint film formed using the paint of Comparative Example 1 was coated with a paint that did not contain polyetheramine (A1-1). It was inferior in that the evaluation result regarding time was evaluated as "x".

In addition, since the coating films formed using the coating materials of Comparative Examples 2 and 3 were coated with a coating material that did not contain the alicyclic polyamine (A1-2), the film remained intact even after 24 hours from the application. was not in a state of curing and drying, and was inferior in that the evaluation result regarding coating film curing was evaluated as "x".

In addition, since the coating film formed using the coating material of Comparative Example 4 was coated with a coating material that did not contain (poly)amidoamine (A1-3), the pot life of the coating material was short, thereby It was inferior in that the evaluation result regarding usage time was evaluated as "x".

In addition, the coating film formed using the coating material of Comparative Example 5 was coated with a coating material containing a small amount of the curing agent (A) mixed with 100 parts by mass of the main component (B). However, the film was not in a cured and dried state, and therefore the evaluation result regarding the coating film curing was evaluated as "x", which was inferior.

In addition, the coating film formed using the coating material of Comparative Example 6 was coated with a coating material containing a large amount of the curing agent (A) mixed with 100 parts by mass of the main agent (B). It was difficult to obtain a thick coating film. In addition, even if a thick coating film could be formed with one coating, the film was not in a state of curing and drying even after 24 hours had passed since the coating, and as a result, the evaluation result regarding the coating film curing was " It was also inferior in that it was evaluated as ×.

Although the embodiments and examples of the present invention have been described above, the embodiments and examples described above do not limit the scope of the invention according to the claims. Also, it should be noted that not all combinations of features described in the embodiments and examples are essential to the means for solving the problems of the invention.

Claims (9)

A paint containing a curing agent (A) and a main agent (B),
The curing agent (A) is
a polyetheramine (A1-1) having a functionality of two or more, and
an alicyclic polyamine (A1-2);
(Poly) amidoamine (A1-3) and
The main agent (B) is
A bisphenol A type epoxy resin (B1) having a molecular weight in the range of more than 400 to 4000 or less;
a low molecular weight epoxy compound (B2) having a molecular weight of 400 or less;
containing a reinforcing material (B3),
A paint in which the curing agent (A) is mixed with 100 parts by mass of the main agent (B) in an amount of 22 parts by mass or more and 35 parts by mass or less. The paint according to claim 1, wherein the polyetheramine (A1-1) contains tri- or higher functionality. 3. A paint according to claim 1 or 2, wherein the curing agent (A) further contains a non-reactive diluent (A2). 4. The paint according to claim 3, wherein said non-reactive diluent (A2) consists of a phenol-modified hydrocarbon resin. In the curing agent (A),
The content of the polyetheramine (A1-1) is in the range of 10% by mass or more and 40% by mass or less,
The content of the alicyclic polyamine (A1-2) is in the range of 10% by mass or more and 40% by mass or less,
The content of the (poly)amidoamine (A1-3) is in the range of 10% by mass or more and 65% by mass or less,
The paint according to claim 3 or 4, wherein the content of said non-reactive diluent (A2) is 40% by mass or less. 6. The paint according to any one of claims 1 to 5, wherein the reinforcing material (B3) contains silica and alumina. In the main agent (B),
The content of the bisphenol A type epoxy resin (B1) is in the range of 15% by mass or more and 35% by mass or less,
The content of the low molecular weight epoxy compound (B2) is in the range of 35% by mass or more and 55% by mass or less,
The paint according to any one of claims 1 to 6, wherein the content of the reinforcing material (B3) is in the range of 20% by mass or more and 50% by mass or less. A curing agent (A) containing a polyetheramine (A1-1) that is difunctional or trifunctional or more, an alicyclic polyamine (A1-2), and a (poly)amidoamine (A1-3), and
A main agent (B) containing a bisphenol A type epoxy resin (B1) having a molecular weight in the range of more than 400 to 4000 or less, a low molecular weight epoxy compound (B2) having a molecular weight of 400 or less, and a reinforcing material (B3),
A mixing step of mixing the curing agent (A) with 100 parts by mass of the main agent (B) so as to be in the range of 22 parts by mass or more and 35 parts by mass or less to prepare a paint;
A coating and curing step of forming a cured coating film by drying after coating the coating material on the surface of the base material;
A method for forming a coating film. 9. The method of forming a coating film according to claim 8, wherein in the coating and curing step, the coating material is applied to the surface of the substrate using a roller.