One-part epoxy resin composition and cured product thereof, adhesive, coating, primer for concrete, and sealant

Abstract

To provide a one-part epoxy resin composition that is superior in low viscosity, tack-free drying property, and smoothness of the resulting coating film, and a cured product thereof, an adhesive, a coating, a primer for concrete, and a sealant.SOLUTION: The present invention provides a one-part epoxy resin composition comprising: an epoxy resin (A); and a latent epoxy resin curing agent (B), which includes a ketimine (B1) produced by reacting a diamine represented by the general formula (1) and a ketone having 4 to 9 carbon atoms, and a cured product thereof, an adhesive, a coating, a primer for concrete, and a sealant. H2 N-CH2-X-CH2-NH2 (1) (In the formula (1), X represents a phenylene group or a cyclohexylene group).SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a one-component epoxy resin composition, a cured product thereof, an adhesive, a paint, a primer for concrete, and a sealing agent.

Background Art

[0002] A ketimine-modified product obtained by reacting a polyamine with a ketone is known as a curing agent for a one-component epoxy resin composition. More specifically, the ketimine-modified product is a latent curing agent that reacts with moisture in the air to dissociate, and the released polyamine acts as an epoxy resin curing agent.

[0003] For example, in Patent Document 1, a compound obtained by a dehydration reaction of norbornanediamine with carboxylic acids or ketones is proposed as a curing agent for resins capable of producing resins with little odor, excellent appearance, mechanical properties, water resistance, and chemical resistance.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, when the invention product described in Patent Document 1 is used as a latent curing agent for a one-component epoxy resin composition, further improvement is desired in the low viscosity, touch dryness of the resulting composition, and smoothness of the resulting coating film. An object of the present invention is to provide a one-component epoxy resin composition excellent in low viscosity, touch dryness, and smoothness of the resulting coating film, and a cured product, an adhesive, a paint, a primer for concrete, and a sealing agent thereof.

Means for Solving the Problems

[0006] The present inventors have found that a one-component epoxy resin composition containing an epoxy resin and a latent epoxy resin curing agent containing a ketimine obtained by reacting a specific diamine with a ketone can solve the above problems. That is, the present invention relates to the following. [1] An epoxy resin (A) and a latent epoxy resin curing agent (B) containing a ketimine (B1) obtained by reacting a diamine represented by the following general formula (1) with a ketone having 4 to 9 carbon atoms, and a one-component epoxy resin composition containing the same. H2N-CH2-X-CH2-NH2 (1) (In formula (1), X is a phenylene group or a cyclohexylene group.) [2] The one-component epoxy resin composition according to [1], wherein X in the general formula (1) contains a cyclohexylene group. [3] The one-component epoxy resin composition according to [2], wherein the ratio of the cis form / trans form of the cyclohexylene group is 95 / 5 to 30 / 70. [4] The one-component epoxy resin composition according to any one of [1] to [3], wherein the ketone contains methyl isopropyl ketone. [5] The one-component epoxy resin composition according to any one of [1] to [4], wherein the ketimine (B1) is obtained by reacting the ketone in the range of 2 to 12 moles with respect to 1 mole of the diamine. [6] The one-component epoxy resin composition according to any one of [1] to [5], wherein the epoxy resin (A) contains a polyfunctional epoxy resin having an aromatic ring or an alicyclic structure. [7] A cured product of the one-component epoxy resin composition according to any one of [1] to [6]. [8] An adhesive containing the one-component epoxy resin composition according to any one of [1] to [6]. [9] A paint containing the one-component epoxy resin composition according to any one of [1] to [6].

[10] A primer for concrete containing the one-component epoxy resin composition according to any one of [1] to [6]. A sealing agent containing the one-component epoxy resin composition according to any one of

[11] [1] to [6].

Advantages of the Invention

[0007] According to the present invention, it is possible to provide a one-component epoxy resin composition excellent in low viscosity, dry-to-touch property, and smoothness of the resulting coating film, and a cured product, an adhesive, a paint, a primer for concrete, and a sealing agent thereof.

Modes for Carrying Out the Invention

[0008] [Definition] In this specification, the "one-component epoxy resin composition" means a composition containing an epoxy resin and a latent epoxy resin curing agent. The "latent epoxy resin curing agent" means a component that can release an epoxy resin curing agent such as a polyamine by reacting with moisture in the air and dissociating, and typically includes ketimine.

[0009] [One-Component Epoxy Resin Composition] The one-component epoxy resin composition of the present invention (hereinafter also referred to as the "(epoxy resin) composition of the present invention") contains an epoxy resin (A), a diamine represented by the following general formula (1), and a ketimine (B1) obtained by reacting a ketone having 4 to 9 carbon atoms, and a latent epoxy resin curing agent (B). It is a one-component epoxy resin composition. H2N-CH2-X-CH2-NH2(1) (In formula (1), X is a phenylene group or a cyclohexylene group.) By configuring the epoxy resin composition of the present invention as described above, it is excellent in low viscosity, dry-to-touch property, and smoothness of the resulting coating film. These can be evaluated by the methods described in the examples.

[0010] Moreover, the coating film obtained from the epoxy resin composition of the present invention also has good salt water resistance. In this specification, "salt water resistance of the coating film" means that after the coating film formed on a substrate (zinc phosphate-treated iron plate) is cross-cut in accordance with JIS K5600-7-9:2006 and 5% salt water is sprayed onto the coating film, there is little peeling of the coating film and rust generation on the substrate. Specifically, the salt water resistance of the coating film can be evaluated by the method described in the examples.

[0011] Although the reason why the one-component epoxy resin composition of the present invention exhibits the above effects is not clear, it is presumed as follows. Since both the diamine and the ketone, which are the raw materials of the ketimine (B1), have low viscosities, it is considered that the resulting ketimine (B1) and the one-component epoxy resin composition containing the same also have low viscosities. The diamine, which is the raw material of the ketimine (B1), contains a ring structure but has a molecular structure that is not sterically bulky in three dimensions. Therefore, it is considered that the cured product (coating film) of the epoxy resin composition obtained using this has a relatively small free volume and it is difficult for moisture to penetrate. As a result, it is considered that the coating film made of the one-component epoxy resin composition of the present invention has good touch-dry properties, and surface unevenness due to moisture penetration into the coating film is suppressed, and the smoothness is also improved. In addition, since the diamine, which is the raw material of the ketimine (B1), is not sterically bulky in three dimensions, it is considered that it easily reacts with the epoxy resin (A) and can form a dense coating film structure. Due to this effect, it is considered that the coating film made of the one-component epoxy resin composition of the present invention is also excellent in salt water resistance.

[0012] <Epoxy resin (A)> The epoxy resin (A) (hereinafter also referred to as "component (A)") is not particularly limited as long as it is a resin having two or more epoxy groups capable of reacting with the active hydrogen in the diamine derived from the latent epoxy resin curing agent (B) (hereinafter also referred to as "component (B)"), and it may be any of saturated or unsaturated aliphatic compounds, alicyclic compounds, aromatic compounds, and heterocyclic compounds. From the viewpoints of touch-dry properties, smoothness of the coating film, and improvement of salt water resistance, the epoxy resin (A) preferably contains a polyfunctional epoxy resin having an aromatic ring or an alicyclic structure. From the viewpoints of touch dryness, smoothness of the coating film, and improvement in salt water resistance, the content of the polyfunctional epoxy resin having an aromatic ring or an alicyclic structure in the epoxy resin (A) is preferably 50% by mass or more, more preferably 60% by mass or more, still more preferably 70% by mass or more, even more preferably 80% by mass or more, even more preferably 85% by mass or more, even more preferably 90% by mass or more, even more preferably 95% by mass or more, and is 100% by mass or less.

[0013] The polyfunctional epoxy resin having an aromatic ring or an alicyclic structure includes, for example, at least one selected from the group consisting of a polyfunctional epoxy resin having a glycidylamino group derived from metaxylylenediamine, a polyfunctional epoxy resin having a glycidylamino group derived from paraxylylenediamine, a polyfunctional epoxy resin having a glycidylamino group derived from 1,3-bis(aminomethyl)cyclohexane, a polyfunctional epoxy resin having a glycidylamino group derived from 1,4-bis(aminomethyl)cyclohexane, a polyfunctional epoxy resin having a glycidylamino group derived from diaminodiphenylmethane, a polyfunctional epoxy resin having a glycidylamino group and / or a glycidyloxy group derived from para-aminophenol, a polyfunctional epoxy resin having a glycidyloxy group derived from resorcinol, a polyfunctional epoxy resin having a glycidyloxy group derived from bisphenol A or a hydrogenated product thereof, a polyfunctional epoxy resin having a glycidyloxy group derived from bisphenol F or a hydrogenated product thereof, and a polyfunctional epoxy resin having a glycidyloxy group derived from phenol novolak. These epoxy resins can also be used as a mixture of two or more.

[0014] Among them, from the viewpoints of finger-touch drying property, smoothness of the coating film, and improvement of salt water resistance, the epoxy resin (A) preferably contains a polyfunctional epoxy resin having an aromatic ring, more preferably a polyfunctional epoxy resin having a glycidylamino group derived from metaxylylenediamine, a polyfunctional epoxy resin having a glycidylamino group derived from paraxylylenediamine, a polyfunctional epoxy resin having a glycidyloxy group derived from bisphenol A, and a polyfunctional epoxy resin having a glycidyloxy group derived from bisphenol F, and further preferably contains at least one selected from the group consisting of a polyfunctional epoxy resin having a glycidyloxy group derived from bisphenol A and a polyfunctional epoxy resin having a glycidyloxy group derived from bisphenol F, and even more preferably contains a polyfunctional epoxy resin having a glycidyloxy group derived from bisphenol A.

[0015] From the viewpoint of obtaining a one-component epoxy resin composition with low viscosity, the epoxy resin (A) may contain a reactive diluent in addition to the polyfunctional epoxy resin having an aromatic ring or an alicyclic structure. Examples of the reactive diluent include low-molecular compounds having at least one epoxy group, specifically, aromatic monoglycidyl ethers such as phenyl glycidyl ether and cresyl glycidyl ether; alkyl monoglycidyl ethers such as butyl glycidyl ether, hexyl glycidyl ether, octyl glycidyl ether, decyl glycidyl ether, lauryl glycidyl ether, and tetradecyl glycidyl ether; and diglycidyl ethers of aliphatic diols such as 1,3-propanediol diglycidyl ether, 1,4-butanediol diglycidyl ether, neopentyl glycol diglycidyl ether, and 1,6-hexanediol diglycidyl ether. Among these, from the viewpoint of obtaining a low-viscosity one-component epoxy resin composition, the reactive diluent preferably contains at least one selected from the group consisting of alkyl monoglycidyl ethers and diglycidyl ethers of aliphatic diols, and more preferably contains an alkyl monoglycidyl ether. The number of carbon atoms of the alkyl in the alkyl monoglycidyl ether is preferably 3 to 18, more preferably 4 to 12, from the viewpoint of obtaining a low-viscosity one-component epoxy resin composition. The above reactive diluent can be used alone or in combination of two or more.

[0016] When the epoxy resin (A) contains a reactive diluent, the content of the reactive diluent in the epoxy resin (A) is preferably 1% by mass or more, more preferably 2% by mass or more, still more preferably 5% by mass or more, from the viewpoint of obtaining a low-viscosity one-component epoxy resin composition, and is preferably 40% by mass or less, more preferably 30% by mass or less, still more preferably 20% by mass or less, from the viewpoints of touch dryness, smoothness of the coating film, and improvement of salt water resistance.

[0017] The epoxy resin (A) may be either solid or liquid, but preferably contains a liquid epoxy resin from the viewpoint of obtaining a low-viscosity one-component epoxy resin composition. As used herein, the "solid epoxy resin" means an epoxy resin that is solid at room temperature (25°C), and the "liquid epoxy resin" means an epoxy resin that is liquid at room temperature (25°C).

[0018] The epoxy equivalent of the epoxy resin (A) is preferably 80 g / equivalent or more, more preferably 100 g / equivalent or more, still more preferably 120 g / equivalent or more, even more preferably 150 g / equivalent or more, from the viewpoints of touch dryness, smoothness of the coating film, and improvement of salt water resistance, and is preferably 1000 g / equivalent or less, more preferably 800 g / equivalent or less, still more preferably 500 g / equivalent or less, even more preferably 300 g / equivalent or less, even more preferably 250 g / equivalent or less, from the viewpoint of obtaining a low-viscosity one-component epoxy resin composition. The epoxy equivalent of the epoxy resin (A) means the epoxy equivalent of the mixture when the epoxy resin (A) is a mixture of two or more epoxy resins.

[0019] As the epoxy resin (A), commercially available products can also be used. Examples of commercially available epoxy resins include "jER825", "jER827", "jER828", "jER801N", "jER801PN", "jER802", "jER811", "jER813", "jER819", "jER806", "jER806H", "jER807", etc. manufactured by Mitsubishi Chemical Corporation.

[0020] <Latent epoxy resin curing agent (B)> The latent epoxy resin curing agent (B) contains a ketimine (B1) obtained by reacting a diamine represented by the following general formula (1) with a ketone having 4 to 9 carbon atoms. H2N-CH2-X-CH2-NH2(1) (In formula (1), X is a phenylene group or a cyclohexylene group.)

[0021] (Ketimine (B1)) The ketimine (B1) is a compound obtained by reacting the diamine represented by the general formula (1) with a ketone having 4 to 9 carbon atoms.

[0022] [Diamine represented by general formula (1)] The diamine represented by the general formula (1) is released by the dissociation of the ketimine (B1) and acts as an amine-based epoxy resin curing agent. X in the general formula (1) is a phenylene group or a cyclohexylene group, and preferably contains a cyclohexylene group from the viewpoint of a shorter time until it becomes a semi-dry (dust free) state. Specifically, X in the general formula (1) is at least one selected from the group consisting of a 1,2-phenylene group, a 1,3-phenylene group, a 1,4-phenylene group, a 1,2-cyclohexylene group, a 1,3-cyclohexylene group, and a 1,4-cyclohexylene group. Also, from the viewpoints of low viscosity, dry-to-touch property, smoothness of the coating film, and improvement in salt water resistance, X in the general formula (1) preferably contains at least one selected from the group consisting of a 1,3-phenylene group, a 1,4-phenylene group, a 1,3-cyclohexylene group, and a 1,4-cyclohexylene group, and more preferably contains at least one selected from the group consisting of a 1,3-phenylene group and a 1,3-cyclohexylene group.

[0023] The cyclohexylene group in this specification includes both cis and trans isomers. The ratio of the cis isomer to the trans isomer of the cyclohexylene group is preferably in the range of 95 / 5 to 30 / 70, more preferably in the range of 90 / 10 to 40 / 60, still more preferably in the range of 85 / 15 to 50 / 50, and even more preferably in the range of 80 / 20 to 60 / 40 from the viewpoints of improvement in low viscosity, dry-to-touch property, and smoothness of the coating film.

[0024] The diamine represented by the general formula (1) is at least one selected from the group consisting of xylylenediamine and bis(aminomethyl)cyclohexane, and preferably contains bis(aminomethyl)cyclohexane from the viewpoint of a shorter time until it becomes a semi-dry (dust free) state. The ratio of the cis isomer to the trans isomer of bis(aminomethyl)cyclohexane is preferably in the range of 95 / 5 to 30 / 70, more preferably in the range of 90 / 10 to 40 / 60, still more preferably in the range of 85 / 15 to 50 / 50, and even more preferably in the range of 80 / 20 to 60 / 40 from the viewpoints of improvement in low viscosity, dry-to-touch property, and smoothness of the coating film. Specifically, the diamine represented by the general formula (1) is at least one selected from the group consisting of o-xylylenediamine, meta-xylylenediamine (MXDA), para-xylylenediamine (PXDA), 1,2-bis(aminomethyl)cyclohexane, 1,3-bis(aminomethyl)cyclohexane, and 1,4-bis(aminomethyl)cyclohexane. Also, from the viewpoints of low viscosity, dry-to-touch property, smoothness of the coating film, and improvement in salt water resistance, the diamine represented by the general formula (1) preferably contains at least one selected from the group consisting of metaxylylenediamine, paraxylylenediamine, 1,3-bis(aminomethyl)cyclohexane, and 1,4-bis(aminomethyl)cyclohexane, and more preferably contains at least one selected from the group consisting of metaxylylenediamine and 1,3-bis(aminomethyl)cyclohexane.

[0025] (ketone having 4 to 9 carbon atoms) The ketone used for producing the ketimine (B1) has 4 to 9 carbon atoms from the viewpoints of low viscosity, dry-to-touch property, smoothness of the coating film, and improvement in salt water resistance, preferably a ketone having 4 to 8 carbon atoms, more preferably a ketone having 4 to 6 carbon atoms, and still more preferably a ketone having 4 to 5 carbon atoms. Specific examples of the ketone include methyl ethyl ketone, diethyl ketone, methyl isopropyl ketone, ethyl isopropyl ketone, diisopropyl ketone, methyl isobutyl ketone, methyl pentyl ketone, ethyl pentyl ketone, isopropyl pentyl ketone, dibutyl ketone, etc., and one or more of these can be used. Among the above, the ketone having 4 to 9 carbon atoms preferably contains at least one selected from the group consisting of methyl ethyl ketone, diethyl ketone, methyl isopropyl ketone, ethyl isopropyl ketone, and methyl isobutyl ketone from the viewpoints of low viscosity, dry-to-touch property, smoothness of the coating film, and improvement in salt water resistance, more preferably contains at least one selected from the group consisting of diethyl ketone and methyl isopropyl ketone, and still more preferably contains methyl isopropyl ketone.

[0026] Ketimine (B1) preferably contains at least one diamine selected from the group consisting of metaxylylenediamine, paraxylylenediamine, 1,3-bis(aminomethyl)cyclohexane, and 1,4-bis(aminomethyl)cyclohexane, and a ketone containing at least one selected from the group consisting of methyl ethyl ketone, diethyl ketone, methyl isopropyl ketone, ethyl isopropyl ketone, and methyl isobutyl ketone. More preferably, it contains at least one ketimine obtained by reacting metaxylylenediamine with diethyl ketone, at least one ketimine obtained by reacting metaxylylenediamine with methyl isopropyl ketone, at least one ketimine obtained by reacting 1,3-bis(aminomethyl)cyclohexane with diethyl ketone, and at least one ketimine obtained by reacting 1,3-bis(aminomethyl)cyclohexane with methyl isopropyl ketone. From the perspective of a shorter time to reach a semi-dry (dust free) state, it is even more preferably contains at least one selected from the group consisting of the ketimine obtained by reacting 1,3-bis(aminomethyl)cyclohexane with diethyl ketone and the ketimine obtained by reacting 1,3-bis(aminomethyl)cyclohexane with methyl isopropyl ketone.

[0027] From the perspective of improving the reaction efficiency, ketimine (B1) is obtained by reacting a ketone having 4 to 9 carbon atoms with 1 mol of the diamine obtained by the general formula (1), preferably in the range of 2 to 12 mol, more preferably 3 to 10 mol, still more preferably 3 to 8 mol, even more preferably 3 to 6 mol. The molar amount referred to here means the charged amount (mol) during the reaction. Although ketimine (B1) may contain a small amount of unreacted diamine, from the perspective of improving the storage stability of the one-component epoxy resin composition, it is preferable that the content of the unreacted diamine is small. The content of the unreacted diamine in ketimine (B1) is preferably 8% by mass or less, more preferably 5% by mass or less, still more preferably 2% by mass or less, even more preferably 1% by mass or less, even more preferably 0.5% by mass or less, even more preferably 0.1% by mass or less, and even more preferably 0% by mass. The content of unreacted diamine in ketimine (B1) can be determined by gas chromatography (GC) analysis.

[0028] (Viscosity) The viscosity of ketimine (B1) at 25°C is preferably 1 mPa·s or more, and from the viewpoint of the low viscosity of the resulting one-component epoxy resin composition, it is preferably 50 mPa·s or less, more preferably 30 mPa·s or less, still more preferably 20 mPa·s or less, and even more preferably 15 mPa·s or less. The viscosity of ketimine (B1) at 25°C can be measured using an E-type viscometer, specifically, by the method described in the examples.

[0029] (Method for producing ketimine (B1)) The method for producing ketimine (B1) is not particularly limited, and known methods can be used. For example, a method of heating the diamine represented by the general formula (1) and a ketone having 4 to 9 carbon atoms in a solvent and refluxing while removing the by-produced water using a Dean-stark apparatus can be mentioned. The reaction molar ratio of the diamine represented by the general formula (1) and the ketone having 4 to 9 carbon atoms is, from the viewpoint of improving the reaction efficiency, such that the number of moles of the ketone having 4 to 9 carbon atoms per 1 mole of the diamine obtained by the general formula (1) is preferably 2 to 12 moles, more preferably 3 to 10 moles, still more preferably 3 to 8 moles, and even more preferably 3 to 6 moles.

[0030] The solvent used for the production of ketimine (B1) is preferably a solvent capable of dissolving the diamine represented by the general formula (1) and the ketone having 4 to 9 carbon atoms and capable of azeotroping with water, and examples thereof include toluene, xylene, n-hexane, heptane, cyclohexane, etc. The amount of the solvent used for the production of ketimine (B1) is preferably 0.1 to 5 mass times, more preferably 0.2 to 3 mass times, still more preferably 0.3 to 2 mass times, based on the total amount of the diamine represented by the general formula (1) and the ketone having 4 to 9 carbon atoms, from the viewpoints of improving the reaction efficiency and the ease of azeotropic dehydration.

[0031] In the production of ketimine (B1), when reacting the diamine represented by the general formula (1) with a ketone having 4 to 9 carbon atoms, the reaction temperature is preferably in the range of 80 to 140 °C, more preferably 90 to 130 °C, from the viewpoint of performing the reaction under reflux and improving the reaction efficiency. When reacting the diamine represented by the general formula (1) with a ketone having 4 to 9 carbon atoms, the reaction time is preferably 0.5 to 24 hours, more preferably 1 to 18 hours, from the viewpoints of completing the reaction and improving the production efficiency. Further, when water of the theoretical amount distills out during the reaction, the reaction time is preferably 30 minutes or more, more preferably 1 hour or more, after the water of the theoretical amount has escaped. The reaction time referred to here means the reflux time. After the completion of the above reaction, distillation purification can be carried out as necessary to obtain ketimine (B1).

[0032] The latent epoxy resin curing agent (B) can also contain a latent epoxy resin curing agent other than ketimine (B1), for example, a ketimine other than ketimine (B1), as long as the effects of the present invention are not inhibited. However, from the viewpoints of low viscosity, dry-to-touch property, smoothness of the coating film, and improvement of salt water resistance, the content of ketimine (B1) in the latent epoxy resin curing agent (B) is preferably 50% by mass or more, more preferably 60% by mass or more, still more preferably 70% by mass or more, even more preferably 80% by mass or more, even more preferably 90% by mass or more, even more preferably 95% by mass or more, and 100% by mass or less.

[0033] <Other components> The epoxy resin composition of the present invention may further contain optional components such as a modifying component such as a plasticizer, a flow adjusting component such as a thixotropic agent, a filler, a pigment, a leveling agent, an adhesion promoter, an elastomer, a non-reactive diluent, an antioxidant, and a solvent, as long as the effects of the present invention are not inhibited.

[0034] <Content> The content of the epoxy resin (A) in the one-component epoxy resin composition is preferably 10 to 60% by mass, more preferably 15 to 50% by mass, still more preferably 20 to 40% by mass, from the viewpoints of low viscosity, dry-to-touch property, smoothness of the coating film, and improvement of salt water resistance.

[0035] The content of the latent epoxy resin curing agent (B) in the one-component epoxy resin composition is preferably 40 to 90% by mass, more preferably 50 to 85% by mass, still more preferably 60 to 80% by mass, from the viewpoints of low viscosity, dry-to-touch property, smoothness of the coating film, and improvement of salt water resistance.

[0036] Further, the content ratio of the epoxy resin (A) and the latent epoxy resin curing agent (B) in the one-component epoxy resin composition is such that the ratio of the number of active hydrogens in the diamine derived from the latent epoxy resin curing agent (B) to the number of epoxy groups in the epoxy resin (A) (number of active hydrogens in the diamine derived from the latent epoxy resin curing agent (B) / number of epoxy groups in the epoxy resin (A)) is preferably 1 / 0.5 to 1 / 2, more preferably 1 / 0.7 to 1 / 1.5, still more preferably 1 / 0.8 to 1 / 1.2. The "number of active hydrogens in the diamine derived from the latent epoxy resin curing agent (B)" means the number of active hydrogens in the theoretical amount of diamine released from the ketimine contained in the latent epoxy resin curing agent (B).

[0037] The total content of the epoxy resin (A) and the latent epoxy resin curing agent (B) in the one-component epoxy resin composition is preferably 50% by mass or more, more preferably 60% by mass or more, still more preferably 70% by mass or more, even more preferably 80% by mass or more, even more preferably 90% by mass or more, and 100% by mass or less, from the viewpoint of effectively obtaining the effects of the present invention.

[0038] In addition, from the viewpoint of improving storage stability, the one-component epoxy resin composition preferably has a lower water content. The water content in the one-component epoxy resin composition is preferably 1% by mass or less, more preferably 0.5% by mass or less, still more preferably 0.1% by mass or less, and even more preferably 0% by mass.

[0039] <Viscosity> The viscosity of the one-component epoxy resin composition at 25°C is preferably 50 to 2,000 mPa·s, more preferably 100 to 1,500 mPa·s, still more preferably 200 to 1,000 mPa·s, and even more preferably 300 to 900 mPa·s from the viewpoints of improving handleability and low viscosity. The viscosity of the one-component epoxy resin composition at 25°C can be specifically measured by the method described in the examples using an E-type viscometer.

[0040] <Manufacturing method of one-component epoxy resin composition> There are no particular restrictions on the manufacturing method of the one-component epoxy resin composition. For example, it can be manufactured by blending each component used in the one-component epoxy resin composition and mixing them using a known apparatus. There are no particular restrictions on the mixing temperature and mixing time of each component in the production of the one-component epoxy resin composition. Usually, the mixing temperature can be selected in the range of 0 to 60°C, and the mixing time can be selected in the range of 5 minutes to 6 hours.

[0041] [Cured product] The present invention further provides a cured product of the one-component epoxy resin composition of the present invention. The cured product is obtained by curing the one-component epoxy resin composition. The curing conditions of the one-component epoxy resin composition may be in the presence of moisture in the air or the like, and other conditions are appropriately selected according to the use and form. For example, the curing temperature of the one-component epoxy resin composition can be selected in the range of -10 to 150°C, and the curing time can be selected in the range of 0.5 minutes to 7 days. The form of the cured product of the present invention is not particularly limited either and can be selected according to the use.

[0042] [Applications] The present invention further provides an adhesive, a paint, a primer for concrete, or a sealing agent containing the one-component epoxy resin composition of the present invention. The one-component epoxy resin composition of the present invention may be used as an adhesive, a paint, a primer for concrete, or a sealing agent as it is. Further, in the one-component epoxy resin composition of the present invention, within a range that does not inhibit the effects of the present invention, a modifying component such as a plasticizer, a fluidity adjusting component such as a thixotropic agent, a filler, a pigment, a leveling agent, a tackifier, an elastomer, a non-reactive diluent, an antioxidant, a solvent, or other optional components may be added, and it can also be used as an adhesive, a paint, a primer for concrete, or a sealing agent.

[0043] From the viewpoint of effectively expressing the effects of the present invention, the content of the one-component epoxy resin composition in the adhesive, paint, primer for concrete, or sealing agent is preferably 50% by mass or more, more preferably 60% by mass or more, still more preferably 70% by mass or more, even more preferably 80% by mass or more, even more preferably 90% by mass or more, even more preferably 95% by mass or more, and is 100% by mass or less.

Examples

[0044] The present invention will be described in detail below with reference to examples and comparative examples, but the present invention is not limited to the following examples. The measurement and evaluation of the epoxy resin curing agent and the one-component epoxy resin composition were carried out by the following methods.

[0045] (1) Viscosity The viscosities of the ketimine and the one-component epoxy resin composition at 25°C were measured at a rotational speed of 20 rpm using an E-type viscometer "TVE-22H type viscometer, cone plate type" (manufactured by Toki Sangyo Co., Ltd.).

[0046] (2) Touch dry The one-component epoxy resin composition was applied onto a substrate (zinc phosphate-treated iron plate, "SPCC-SD PB-N144" manufactured by Partec Co., Ltd., 0.8×70×150 mm) using an applicator under the conditions of 23°C and 50% R.H. to form a coating film (coating film thickness immediately after coating: 200 μm). This coating film was allowed to stand under the conditions of 23°C and 50% R.H., and after 1, 2, and 7 days, touch dry evaluation was carried out by touch according to the following criteria. Ex: Even when pressing with a force of about 50 N, there is no stickiness of the coating film and no fingerprint residue G: When pressing with a force of about 50 N, there is no stickiness of the coating film, but there is fingerprint residue after finger contact F: When pressing with a force of about 50 N, there is stickiness of the coating film, but there is no stickiness of the coating film when pressing with a force of about 5 N P: When pressing with a force of about 5 N, there is stickiness of the coating film

[0047] (3) RCI drying time A one - component epoxy resin composition was applied onto a glass plate (manufactured by Taiyu Kikai Co., Ltd., 25×348×2.0 mm) using an applicator under the conditions of 23°C and 50% R.H. to form a coating film (coating film thickness immediately after coating: 200 μm). The glass plate with the formed coating film was set in a paint drying time measuring instrument (manufactured by Taiyu Kikai Co., Ltd.). When the needle of the measuring instrument scratched the surface of the coating film, the streaks were observed, and the arrival times at each drying stage (Set to Touch, Dust Free, Dry Through) were measured according to the following criteria. The shorter the time, the faster the curing speed is indicated Set to Touch: The time until a needle mark starts to remain on the coating film Dust Free: The time until the needle mark emerges from the coating film onto the coating film surface Dry Through: The time until the needle mark no longer remains on the coating film

[0048] (4) Smoothness of the coating film A one - component epoxy resin composition was applied onto a substrate (phosphate - treated iron plate) in the same manner as in (2) above to form a coating film (coating film thickness immediately after coating: 200 μm). The obtained coating film was stored under the conditions of 23°C and 50% R.H. After 1 day, the appearance of the coating film was visually observed, and the smoothness was evaluated according to the following criteria <Evaluation criteria> Ex: No unevenness G: Slightly uneven F: There are unevenness in some parts, but no problem in use P: There is peeling, or there are unevenness on the entire surface

[0049] (5) 5% Salt Spray Test A one-component epoxy resin composition was applied onto a base material (zinc phosphate-treated iron sheet) in the same manner as in (2) above to form a coating film (coating film thickness immediately after application: 200 μm). After storing this at 23°C and 50% R.H. for 7 days, the non-coated part was sealed with a rust preventive paint (Million Primer and Million Clear, manufactured by Kansai Paint Co., Ltd.) to prepare a test piece. On the surface of the coating film on the test piece, two cuts intersecting diagonally with a length of 50 mm were made using a cutter knife in accordance with JIS K5600-7-9:2006. The above test piece was placed in a salt spray tester (STP-90, manufactured by Suga Test Instruments Co., Ltd., tank temperature 35°C), and salt water (concentration 5 mass%) was continuously sprayed. After 1, 2, 3, and 4 weeks had passed, the appearance of the test piece was visually observed, and the overall appearance, cut part appearance, and rust width were evaluated according to the following criteria. The presence or absence of the occurrence of pitting rust was confirmed by visually observing the surface of the base material in contact with the coating film.

[0050] (Overall Appearance) The test piece after 1 week of salt spray was visually observed and evaluated according to the following criteria. Ex: No pitting rust occurs on the base material, and the appearance of the coating film shows no change. G: Two to three pitting rusts occur on the base material, but the appearance of the coating film shows no change. F: A small amount of pitting rust occurs on the base material, but the appearance of the coating film shows no change, and there are no problems in use. P: A large number of pitting rusts occur on the base material, or the coating film has peeled off.

[0051] (Cut Part Appearance) For the test piece after 1 week of salt spray, the surface of the base material at the part where the coating film was cut was visually observed and evaluated according to the following criteria. Ex: No pitting rust occurs on the base material (cut part), and the appearance of the coating film shows no change. G: Two to three pitting rusts occur on the base material (cut part). F: A small amount of pitting rust occurs on the base material, but there are no problems in use. P: A large number of pitting rusts occur on the base material (cut part).

[0052] (Rust width) For the test pieces after 1, 2, 3, and 4 weeks of salt water spray, the rust width (mm) on the base material generated at the cut part was visually confirmed. The smaller the rust width, the better the corrosion resistance is indicated.

[0053] (6) Content of unreacted diamine in ketimine 0.10 g of ketimine (B1) or (B1’) obtained in the production example and 0.03 g of diphenyl ether (manufactured by Kanto Chemical Co., Inc.) as an internal standard were weighed and diluted with 1.5 g of methanol to prepare a measurement sample. The sample was analyzed under the following conditions using a gas chromatography (GC) analyzer, and the content of unreacted diamine in ketimine (B1) or (B1’) was calculated from the GC area values of the unreacted diamine and the internal standard. <GC measurement conditions> Apparatus: "7890B GC" manufactured by Agilent Technologies, Inc. Column: "CP-Sil 8 CB for Amines" manufactured by Agilent Technologies, Inc. (length 30 m, film thickness 0.25 μm, inner diameter 0.25 mm) Column temperature: 40°C for 10 minutes → temperature increase at 20°C / min → 250°C for 10 minutes → temperature increase at 20°C / min → 300°C for 10 minutes Carrier gas: Helium Carrier gas flow rate: 2.2553 mL / min Injection port pressure: 22.474 psi (constant pressure mode) Detector: FID Injection port temperature: 250°C Detector temperature: 310°C

[0054] Production Example 1 (Production of meta-xylylenediamine (MXDA)-diethyl ketone (DEK) reactant) A separable flask with an internal volume of 1 liter equipped with a stirring blade, a thermometer, a cooling tube, and a Dean-stark apparatus was charged with 136 g (1 mol) of metaxylylenediamine (MXDA, manufactured by Mitsubishi Gas Chemical Company, Inc.), 345 g (4 mol, 4 molar equivalents relative to MXDA) of diethyl ketone (manufactured by Tokyo Chemical Industry Co., Ltd.), and 200 g of toluene as a solvent. The flask was heated until the internal temperature reached 110 to 120 °C, and reflux was carried out for a total of 8 hours while removing the by-produced water using the Dean-stark apparatus. The obtained reaction solution was transferred to an eggplant flask, and the residual diethyl ketone and toluene were distilled off using an evaporator to obtain an MXDA-diethyl ketone reactant which is a ketimine (B1). The viscosity of the obtained reactant at 25 °C and the content of unreacted diamine (MXDA) in the reactant were determined by GC measurement and are shown in Table 1.

[0055] Production Example 2 (Production of 1,3-bis(aminomethyl)cyclohexane (1,3-BAC)-diethyl ketone (DEK) reactant) In Production Example 1, the reaction was carried out in the same manner as in Production Example 1 except that 142 g (1 mol) of 1,3-bis(aminomethyl)cyclohexane (1,3-BAC, manufactured by Mitsubishi Gas Chemical Company, Inc., cis / trans ratio = 77 / 23) was used instead of MXDA to obtain a 1,3-BAC-diethyl ketone reactant which is a ketimine (B1).

[0056] Production Example 3 (Production of MXDA-methyl isopropyl ketone (MIPK) reactant) In Production Example 1, the reaction was carried out in the same manner as in Production Example 1 except that 345 g (4 mol) of methyl isopropyl ketone (MIPK, manufactured by Tokyo Chemical Industry Co., Ltd.) was used instead of diethyl ketone and the reaction (reflux) time was changed to 6 hours to obtain an MXDA-methyl isopropyl ketone reactant which is a ketimine (B1).

[0057] Production Example 4 (Production of 1,3-BAC-methyl isopropyl ketone (MIPK) reactant) In Production Example 2, the reaction was carried out in the same manner as in Production Example 1, except that 345 g (4 mol) of methyl isopropyl ketone (MIPK, manufactured by Tokyo Chemical Industry Co., Ltd.) was used instead of diethyl ketone, and the reaction (reflux) time was changed to 4 hours, to obtain a ketimine (B1), 1,3-BAC-methyl isopropyl ketone reactant.

[0058] Comparative Production Example 1 (Production of norbornanediamine (NBDA)-diethyl ketone (DEK) reactant) In Production Example 1, the reaction was carried out in the same manner as in Production Example 1, except that 154 g (1 mol) of norbornanediamine (NBDA, manufactured by Tokyo Chemical Industry Co., Ltd.) was used instead of MXDA, and the reaction (reflux) time was changed to 5 hours, to obtain a ketimine (B1') for comparative example (hereinafter, ketimines other than ketimine (B1) are referred to as "ketimine (B1')"), NBDA-diethyl ketone reactant.

[0059] Comparative Production Example 2 (Production of norbornanediamine (NBDA)-methyl isopropyl ketone (MIPK) reactant) In Production Example 3, the reaction was carried out in the same manner as in Production Example 3, except that 154 g (1 mol) of norbornanediamine (NBDA, manufactured by Tokyo Chemical Industry Co., Ltd.) was used instead of MXDA, and the reaction (reflux) time was changed to 4 hours, to obtain a ketimine (B1') for comparative example, NBDA-methyl isopropyl ketone reactant.

[0060] The ketimines of the production examples and comparative production examples are summarized in Table 1. According to the GC measurement results under the said measurement conditions, the ketimines obtained in the production examples and comparative production examples were compounds in which 2 moles of ketone were added to 1 mole of diamine.

Table 1

[0061] Examples 1 to 4, Comparative Examples 1 to 2 (Preparation and evaluation of one-component epoxy resin composition) The components described in Tables 2 to 3 were blended and mixed at room temperature (25°C) to prepare a one-component epoxy resin composition. The obtained one-component epoxy resin composition was evaluated by the method described above. The results are shown in Tables 2 and 3.

[0062]

Table 2

[0063]

Table 3

[0064] The components described in Tables 2 to 3 are as follows. The blending amounts (mass %) in the table are the amounts of active ingredients. <Epoxy resin (A)> A liquid epoxy resin having a glycidyloxy group derived from bisphenol A, "jER828" manufactured by Mitsubishi Chemical Corporation, epoxy equivalent: 186 g / equivalent

[0065] In addition, the "number of active hydrogens in the diamine derived from the curing agent (B)" described in Tables 2 to 3 means the number of active hydrogens in the diamine released from the ketimine contained in the curing agent (B) in the theoretical amount.

[0066] From Tables 2 to 3, it can be seen that the one-component epoxy resin composition of the present invention has a lower viscosity compared to the one-component epoxy resin composition of the comparative example, and is also excellent in the touch-dry property and smoothness of the formed coating film.

Industrial Applicability

[0067] According to the present invention, it is possible to provide a one-component epoxy resin composition excellent in low viscosity, touch-dry property, and smoothness of the obtained coating film, and a cured product, an adhesive, a paint, a primer for concrete, and a sealing agent thereof.

Claims

1. An epoxy resin (A), a latent epoxy resin curing agent (B) containing a ketimine (B1) obtained by reacting a diamine represented by the following general formula (1) with a ketone having 4 to 9 carbon atoms; A one-component epoxy resin composition comprising: H ２ P ２ -X-CH ２ -NH ２ (1) (In formula (1), X is a phenylene group or a cyclohexylene group.)

2. 2. The one-component epoxy resin composition according to claim 1, wherein X in the general formula (1) contains a cyclohexylene group.

3. 3. The one-component epoxy resin composition according to claim 2, wherein a ratio of cis / trans isomers of the cyclohexylene groups is from 95 / 5 to 30 / 70.

4. The one-component epoxy resin composition according to any one of claims 1 to 3, wherein the ketone comprises methyl isopropyl ketone.

5. The one-component epoxy resin composition according to any one of claims 1 to 4, wherein the ketimine (B1) is obtained by reacting 2 to 12 moles of the ketone with 1 mole of the diamine.

6. The one-component epoxy resin composition according to any one of claims 1 to 5, wherein the epoxy resin (A) comprises a polyfunctional epoxy resin having an aromatic ring or an alicyclic structure.

7. A cured product of the one-component epoxy resin composition according to any one of claims 1 to 6.

8. An adhesive comprising the one-component epoxy resin composition according to any one of claims 1 to 6.

9. A coating material comprising the one-component epoxy resin composition according to any one of claims 1 to 6.

10. A primer for concrete comprising the one-component epoxy resin composition according to any one of claims 1 to 6.

11. A sealant comprising the one-component epoxy resin composition according to any one of claims 1 to 6.

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