Epoxy resin curing agent, epoxy resin composition containing the same, cured product thereof, and lining agent

Abstract

To provide a curing agent for epoxy resins that exhibits good curing properties at low temperatures, has excellent surface gloss in the resulting cured product, and leaves minimal traces of water droplets. [Solution] An epoxy resin curing agent containing as essential components a condensate (A) of an amine compound (a) having at least two primary amino groups in one molecule, formaldehydes (b), and a phenol compound (c) which may have an alkyl group having 1 to 12 carbon atoms, a petroleum resin (B) which is a C5-9 aromatic hydrocarbon fraction polymer, a hydrocarbon solvent (C) with a boiling point of 150°C or higher, and a compound (D) having a tertiary amino group, wherein the mass ratio of each component is in the range of condensate (A) / petroleum resin (B) = 1 to 10, petroleum resin (B) / hydrocarbon solvent (C) = 0.5 to 2.0, and condensate (A) / compound (D) = 1.5 to 4.5.

Description

Technical Field

[0001] The present invention relates to an epoxy resin curing agent, a composition thereof, a cured product, and a lining agent that can provide a cured product with good low-temperature curability and good surface properties.

Background Art

[0002] Epoxy resin-based coating floor materials are often used in factories, warehouses, etc. A two-component type in which the main component, an epoxy resin, and an amine-based curing agent are mixed and applied is the mainstream. Coating floor material manufacturers fix the main agent and provide product numbers for the curing agent in three types for each season, for example, summer, spring / autumn, and winter. A curing agent with excellent curability, that is, a highly reactive amine-based curing agent, is widely used. For example, a mixture of xylylenediamine and an aliphatic polyamine, a mixture of at least one selected from bisphenol A, bisphenol F, and phenol and an alkylphenol having an alkyl group with 9 or more carbon atoms, and an amine-based curing agent obtained by reacting an epoxy resin containing two or more epoxy groups with a condensation reaction product of formaldehyde are disclosed (see, for example, Patent Document 1).

[0003] Furthermore, as a curing agent applicable to a wet surface, an epoxy resin curing agent containing an aromatic amine, an aliphatic amine having an aromatic ring or a cycloalkane ring, a curing accelerator, and a xylene resin (see, for example, Patent Document 2), an epoxy resin curing agent containing a C9-based petroleum resin and a polyamine compound (see, for example, Patent Document 3), etc., various curing agents according to the use and environment are provided.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Patent Document 3

[0005] The cured product obtained from the epoxy resin composition containing the amine-based curing agent provided in Patent Document 1 has the problem of insufficient resistance to moisture and a tendency for unevenness to occur on the surface of the cured product. Furthermore, when using the amine-based curing agent in Patent Document 2, the curing reaction with the epoxy resin tends to be insufficient, resulting in the problem of low gloss on the surface of the cured product. The amine-based curing agent provided in Patent Document 3 has a long pot life and excellent workability, but insufficient curing performance at low temperatures can occur.

[0006] In view of the above circumstances, the problem that the present invention aims to solve is to provide a curing agent for epoxy resins that has good curing properties at low temperatures, excellent surface gloss of the resulting cured product, and leaves few traces of water droplets. [Means for solving the problem]

[0007] The inventors of the present invention diligently studied to solve the above problems and found that the above problems can be solved by using an epoxy resin curing agent which is a specific curing agent, petroleum resin, high boiling point solvent, and curing accelerator blended in specific proportions, thus completing the present invention.

[0008] In other words, the present invention encompasses the following embodiments. [1] an amine compound (a) having at least two primary amino groups in one molecule, Formaldehyde (b) and A phenol compound (c) which may have an alkyl group having 1 to 12 carbon atoms, Condensate (A), Petroleum resin (B) which is a C5-9 aromatic hydrocarbon fraction polymer, Hydrocarbon solvents (C) with a boiling point of 150°C or higher, Compounds having a tertiary amino group (D) It contains as an essential ingredient, The mass ratio of each of the above components is, Condensate (A) / Petroleum resin (B) = 1 to 10 Petroleum resin (B) / Hydrocarbon solvent (C) = 0.5~2.0 Condensate (A) / Compound (D) = 1.5~4.5 Epoxy resin hardeners within this range. [2] The epoxy resin curing agent according to [1], wherein the viscosity at 25°C is in the range of 100 to 1,000 mPa·s. [3] The epoxy resin curing agent according to [1] or [2], wherein the amine compound (a) is an aliphatic polyamine containing an aromatic ring. [4] The epoxy resin curing agent according to any one of [1] to [3] above, wherein the hydrocarbon solvent (C) is benzyl alcohol or phenylxylethane. [5] The epoxy resin curing agent according to any one of [1] to [4], wherein the petroleum resin (B) is contained in an amount of 5 to 20 parts by mass in a total of 100 parts by mass of the condensate (A), the petroleum resin (B), the hydrocarbon solvent (C), and the compound (D). [6] An epoxy resin composition containing an epoxy resin curing agent according to any one of the above items [1] to [5] and an epoxy resin. [7] The epoxy resin composition according to [6], wherein the amount of active hydrogen in the curing agent is in the range of 0.5 to 1.5 equivalents per equivalent of epoxy groups in the epoxy resin. [8] A cured product of the epoxy resin composition described in [6] or [7] above. [9] A lining agent containing the epoxy resin composition described in any of [6] to [8] above. [Effects of the Invention]

[0009] According to the present invention, a curing agent for epoxy resins is provided that exhibits good curing properties at low temperatures, has excellent surface gloss of the resulting cured product, and leaves minimal traces of water droplets. When used in combination with epoxy resin, this curing agent can be suitably used as a lining agent and the like. [Modes for carrying out the invention]

[0010] Next, the embodiments for carrying out the present invention will be described in detail. It should be understood that the present invention is not limited to the following embodiments, and design changes, improvements, etc. can be appropriately made based on the ordinary knowledge of those skilled in the art without departing from the gist of the present invention.

[0011] The epoxy resin curing agent as one form of the present invention is obtained by blending the aforementioned specific components in a specific ratio. Hereinafter, each component will be described in detail.

[0012] The condensate (A) used in the present invention is a condensate of an amine compound (a) having at least two primary amino groups in one molecule, formaldehyde-based compounds (b), and a phenol compound (c) which may have an alkyl group having 1 to 12 carbon atoms.

[0013] The amine compound (a) is not particularly limited, and for example, any of aliphatic polyamines, alicyclic polyamines, aromatic polyamines, heterocyclic polyamines, etc. can be used. Examples of the aliphatic polyamine include aliphatic diamines such as methylenediamine, ethylenediamine, 1,2-diaminopropane, 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 1,7-diaminoheptane, 1,8-diaminooctane, 1,9-diaminononane, 1,10-diaminodecane, o-xylylenediamine, m-xylylenediamine, p-xylylenediamine, etc.;

[0014] aliphatic triamines such as diethylenetriamine, dipropylenetriamine, triethylenetetramine, tripropylenetetramine, tetraethylenepentamine, tetrapropylenetetramine, pentaethylenehexamine, nonaethylenedecamine, trimethylhexamethylenediamine, etc., tetrakis(aminomethyl)methane, bis(3-aminoethyl)amine, bishexamethylenetriamine, etc.;

[0015] alicyclic diamines such as 1,3-bis(aminomethyl)cyclohexane, 1,4-cyclohexanediamine, 4,4'-methylenebiscyclohexylamine, 4,4'-isopropylidenebiscyclohexylamine, norbornad diamine, bis(aminomethyl)cyclohexane, diaminodicyclohexylmethane, isophoronediamine, and menthenediamine;

[0016] aromatic diamines such as bis(cyanoethyl)diethylenetriamine, phenylenediamine, naphthylenediamine, diaminodiphenylmethane, diaminodiethylphenylmethane, 2,2-bis(4-aminophenyl)propane, 4,4'-diaminodiphenyl ether, 4,4'-diaminobenzophenone, 4,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl sulfone, 2,2'-dimethyl-4,4'-diaminodiphenylmethane, 2,4'-diaminobiphenyl, 2,3'-dimethyl-4,4'-diaminobiphenyl, and 3,3'-dimethoxy-4,4'-diaminobiphenyl

[0017] heterocyclic diamines such as 1,4-bis-(8-aminopropyl)-piperazine, etc. are included.

[0018] These may be used alone or in combination of two or more. Among these, aliphatic polyamines containing an aromatic ring are preferable because an epoxy resin composition excellent in low-temperature curability can be obtained, and among them, m-xylylenediamine is more preferable.

[0019] The formaldehydes (b) used in the present invention are not particularly limited, and aldehydes having 1 to 10 carbon atoms are included. For example, formaldehyde, acetaldehyde, paraformaldehyde, crotonaldehyde, furfuraldehyde, succinaldehyde, acetone, propionaldehyde, etc. are included. From the viewpoint of obtaining a curing agent having more excellent low-temperature curability, it is preferable to use formaldehyde and acetaldehyde, and from the viewpoint that Mannich modification proceeds rapidly, it is preferable to use formaldehyde.

[0020] The phenol compound (c) which may have an alkyl group having 1 to 12 carbon atoms is not particularly limited. For example, any compound in which a hydrogen atom bonded to a benzene ring, naphthalene ring, or other aromatic ring is substituted with a hydroxyl group can be used. Examples include phenol represented by C6H5OH, cresol, butylphenol, para-t-butylphenol, para-s-butylphenol, ortho-t-butylphenol, ortho-s-butylphenol, octylphenol, nonylphenol, dodecylphenol, cardanol, etc., which may be used alone or in combination of two or more.

[0021] Among these, phenol and para-t-butylphenol are more preferred because they provide a curing agent with superior low-temperature curing properties.

[0022] The condensate (A) used in the present invention is a condensate of an amine compound (a) having at least two primary amino groups in one molecule, a formaldehyde (b), and a phenol compound (c) which may have an alkyl group having 1 to 12 carbon atoms, and also contains an amino group. The condensate (A) can be produced, for example, by mixing (a) and (c), adding (b) dropwise, and then heating and dehydrating at 50 to 180°C to allow the Mannich reaction to proceed.

[0023] When condensing an amine compound (a), formaldehydes (b), and a phenol compound (c), the reaction molar ratio is usually in the range of 0.5 to 2 (b) and 0.5 to 2 (c) per 1 mole of (a) for reasons of increasing molecular weight and optimizing the actual reaction, and more preferably in the range of 0.7 to 1.5 (b) and 0.7 to 1.5 (c) per 1 mole of (a).

[0024] The petroleum resin (B), which is a C5-9 aromatic hydrocarbon fraction polymer used in the present invention, is not particularly limited, and commercially available resins can be used as appropriate. Examples include C5-based petroleum resins (aliphatic petroleum resins polymerized from fractions such as isoprene, 1,3-pentadiene, cyclopentadiene, methylbutene, and pentene), C9-based petroleum resins (aromatic petroleum resins polymerized from fractions such as α-methylstyrene, o-vinyltoluene, m-vinyltoluene, and p-vinyltoluene), C5 / C9 resins, C9 / dicyclopentadiene resins (C9 / DCPD resins), C5 / dicyclopentadiene resins (C5 / DCPD resins), and hydrogenated C5-based petroleum resins, hydrogenated C9-based petroleum resins, hydrogenated C5 / C9-based petroleum resins, hydrogenated C5 / dicyclopentadiene resins (C5 / hydrogenated DCPD resins), and hydrogenated C9 / dicyclopentadiene resins (C9 / hydrogenated DCPD resins).

[0025] When using amine-based compounds as curing agents for epoxy resins, especially when using amine-based compounds with small molecular weights, these compounds tend to migrate to the surface of the cured coating during curing. As a result, they may react with carbon dioxide in the air, causing whitening, wrinkles, or shrinkage on the surface, and the surface gloss tends to be low. In the present invention, it is believed that using mainly the petroleum resin (B) protects the amine-based compounds that have migrated to the surface and suppresses the reaction with carbon dioxide.

[0026] Examples of C9-based petroleum resins include resins obtained by cationic polymerization of monomers such as vinyltoluene, alkylstyrene, and indene, which are petroleum fractions (C9 fractions) with 8 to 10 carbon atoms. A specific example of a C9-based petroleum resin is styrene-based resin. While there are no particular limitations on styrene-based resins, α-methylstyrene-based resin (AMS) is preferably used. Examples of α-methylstyrene-based resins include homopolymers of α-methylstyrene (poly-α-methylstyrene) and copolymers of α-methylstyrene with other compounds including aromatic compounds and phenolic compounds. Other compounds that can constitute this copolymer include styrene, methylstyrene, methoxystyrene, and divinylbenzene. As for α-methylstyrene-based resins, those manufactured by Arizona Chemical Corporation are preferably used.

[0027] Industrially available C9-based petroleum resins include: Maruzen Petrochemical's C9-based petroleum resin; JXTG Energy's T-REZ RD-104, T-REZ PR802, Neopolymer L-90, Neopolymer 120, Neopolymer 130, Neopolymer 140, Neopolymer 150, Neopolymer 160, Neopolymer 170S, Neopolymer M-1, Neopolymer S, Neopolymer S100, Neopolymer 120S, Neopolymer 130S, Neopolymer 120P, Neopolymer E-100, Neopolymer E-130, Neoresin EP-140, Tousoshasei Petrotac 60, Petrotac 70, Petrotac 90, Petrotac 90V, Petrotac 90HS, Petrotac 100V, Petocol LX, Petocol 120, Petocol 130, Petocol 140, and NEVILLE. Examples include CHEMICAL's NP-10, NP-25, NEVPENE9545, NEVEX045, NEVCHEM100, NEVCHEM110, NEVCHEM120, NEVCHEM130, NEVCHEM140, NEVCHEM150, NEVCHEM200, NEVCHEM220, NEVCHEM240, NEVCHEM250, NEVCHEM300, NEVCHEM320, NEVCHEM340, NEVPENE9500, NEVPENE9510, NEVPENE9510-N, NEVPENE9511, etc.

[0028] C5C9 petroleum resins are resins obtained by copolymerizing C5 and C9 fractions, and are also called aliphatic / aromatic copolymer petroleum resins. More specifically, examples include copolymers mainly composed of styrene, vinyltoluene, α-methylstyrene, and indene. Hydrogenated versions of the above petroleum resins may also be used. C5C9 petroleum resins are manufactured and sold by companies such as LUHUA, Qilong, and Tosoh Corporation. Specifically, examples include the following products manufactured by Zeon Corporation: Quinton N180 (softening point: 80°C), Quinton U185 (softening point: 86°C), Quinton U190 (softening point: 90°C), Quinton S195 (softening point: 94°C), Quinton DX395 (softening point: 94°C), Quinton DX390N (softening point: 93°C), Quinton D100 (softening point: 99°C), and Quinton E200S. Examples include N (softening point: 102°C), Quinton D200 (softening point: 102°C), Quinton D295 (softening point: 94°C), Quinton G100B (softening point: 100°C), Quinton G115 (softening point: 115°C), and Tosoh Corporation's product names Petrotac 60 (softening point: 72°C), Petrotac 70 (softening point: 70°C), Petrotac 90 (softening point: 95°C), Petrotac 90V (softening point: 87°C), Petrotac 90HS (softening point: 87°C), Petrotac 100V (softening point: 96°C), etc.

[0029] As a C5-based petroleum resin, for example, polymers of aliphatic hydrocarbons obtained by polymerizing pentene, pentadiene, and isoprene, which are C5 fractions obtained by the thermal decomposition of naphtha in the petrochemical industry, using a Friedel-Crafts type catalyst can be used. Commercially available C5-based petroleum resins include the trade name "Quinton® R100" (manufactured by Nippon Zeon Co., Ltd.).

[0030] These petroleum resins (B) may be used individually or in combination of two or more. Furthermore, from the viewpoint of the water resistance of the cured product when using the resulting curing agent, it is preferable to use one with a softening point in the range of 100 to 150°C.

[0031] The hydrocarbon solvent (C) used in the present invention, which has a boiling point of 150°C or higher, is not particularly limited. However, from the viewpoint of being used to dissolve the petroleum resin (B) and adjust its viscosity, it is preferable that the solvent has a melting point of room temperature or lower, preferably 5°C or lower. Examples include benzyl alcohol, benzyl benzoate, diethylene glycol, diethylene glycol monobutyl ether, butyl carbitol acetate, diethylene glycol monoethyl ether, diethylene glycol monoethyl ether acetate, ethyl benzoate, and ethylene glycol. Examples of industrially available hydrocarbon solvents (C) include ethylene glycol monobutyl ether, acetate acetate, 1-octanol, 2-octanol, propylene glycol, phenylethanol, phenethyl alcohol, phenylethylphenylethane, and PXE (phenylxylethane) from Asahi Chemical Co., Ltd., Swazole 1000, Swazole 1500, Swazole 1800, Swaclean 150 from Maruzen Petrochemical Co., Ltd., Petrozole MC and Petrozole P-1S from Cosmo Trade and Service Co., Ltd., and T-SOL™ 3040FLUID, T-SOL™ AN45FLUID, Naphthezol Grade 160, Naphthezol Grade 200, Naphthezol Grade 220 from ENEOS Corporation, which may be used alone or in combination of two or more. Among these, it is preferable that there is little or no odor problem, and from the viewpoint of industrial availability, it is preferable to use benzyl alcohol and PXE.

[0032] The compound (D) having a tertiary amino group used in the present invention is not particularly limited, but it is preferably one that exhibits a curing-accelerating effect. Examples include amine compounds such as dimethylaminopropylamine, diethylaminopropylamine, di-n-propylaminopropylamine, dibutylaminopropylamine, dimethylaminoethylamine, diethylaminoethylamine, and N-methylpiperazine, as well as 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, and 2-phenylimidazole. Primary or secondary amines having a tertiary amino group in the molecule, such as imidazole compounds like 2-dimethylaminoethanol, 1-methyl-2-dimethylaminoethanol, 1-phenoxymethyl-2-dimethylaminoethanol, 2-diethylaminoethanol, 1-butoxymethyl-2-dimethylaminoethanol, 1-(2-hydroxy-3-phenoxypropyl)-2-methylimidazole, 1-(2-hydroxy-3-phenoxypropyl)-2-ethyl-4-methylimidazole, 1-(2-hydroxy-3 -Butoxypropyl)-2-methylimidazole, 1-(2-hydroxy-3-butoxypropyl)-2-ethyl-4-methylimidazole, 1-(2-hydroxy-3-phenoxypropyl)-2-phenylimidazoline, 1-(2-hydroxy-3-butoxypropyl)-2-methylimidazole, 2-(dimethylaminomethyl)phenol, 2,4,6-tris(dimethylaminomethyl)phenol, N-β-hydroxyethylmorpholine, 2-dimethylaminoethanethiol, 2-mercaptopyridine, 2-benzoimi Examples include alcohols, phenols, thiols, carboxylic acids, and hydrazides having a tertiary amino group in their molecule, such as dazole, 2-mercaptobenzimidazole, 2-mercaptobenzothiazole, 4-mercaptopyridine, N,N-dimethylaminobenzoic acid, N,N-dimethylglycine, nicotinic acid, isonicotinic acid, picolinic acid, N,N-dimethylglycine hydrazide, N,N-dimethylpropionic acid hydrazide, nicotinic acid hydrazide, and isonicotinic acid hydrazide, which may be used alone or in combination of two or more.

[0033] Among these, 2,4,6-tris(dimethylaminomethyl)phenol and 2-(dimethylaminomethyl)phenol are more preferable from the viewpoint of promoting curing at low temperatures.

[0034] In one embodiment of the present invention, the blending ratio of the aforementioned components is such that the mass ratio of the condensate (A) / petroleum resin (B) is in the range of 1 to 10, the petroleum resin (B) / hydrocarbon solvent (C) is in the range of 0.5 to 2.0, and the mass ratio of the condensate (A) / compound (D) is in the range of 1.5 to 4.5. By satisfying these conditions, the epoxy resin composition has good curability, surface whitening is prevented, and a glossy cured product can be obtained.

[0035] A more preferred blending ratio is one in which the condensate (A) / petroleum resin (B) is in the range of 2 to 6, the petroleum resin (B) / hydrocarbon solvent (C) is in the range of 0.8 to 1.5, and the condensate (A) / compound (D) is in the range of 2.0 to 4.0.

[0036] Furthermore, when the epoxy resin curing agent obtained with such a blending ratio is used as a lining agent, it is preferable that the viscosity at 25°C be in the range of 100 to 1,000 mPa·s, and particularly preferably in the range of 300 to 700 mPa·s, from the viewpoint of improving workability when mixed with the epoxy resin described later.

[0037] Furthermore, from the viewpoint of achieving a superior balance of surface gloss and water resistance of the resulting cured product, it is preferable that the content of the petroleum resin (B) is 5 to 20 parts by mass in a total of 100 parts by mass of the condensate (A), the petroleum resin (B), the hydrocarbon solvent (C), and the compound (D).

[0038] The aforementioned epoxy resin curing agent can be used in combination with various epoxy resins to form a two-component epoxy resin composition.

[0039] The epoxy resins mentioned above are not particularly limited, and examples include bisphenol-type epoxy resins, phenylene ether-type epoxy resins, naphthylene ether-type epoxy resins, biphenyl-type epoxy resins, triphenylmethane-type epoxy resins, phenol novolac-type epoxy resins, cresol novolac-type epoxy resins, bisphenol novolac-type epoxy resins, naphthol novolac-type epoxy resins, naphthol-phenol copolymer novolac-type epoxy resins, naphthol-cresol copolymer novolac-type epoxy resins, phenol aralkyl-type epoxy resins, naphthol aralkyl-type epoxy resins, dicyclopentadiene-phenol addition reaction-type epoxy resins, biphenyl aralkyl-type epoxy resins, fluorene-type epoxy resins, xanthene-type epoxy resins, dihydroxybenzene-type epoxy resins, trihydroxybenzene-type epoxy resins, oxazolidone-type epoxy resins, and the like. These epoxy resins can be used individually or in combination of two or more types. Among these, bisphenol-type epoxy resins, hydrogenated bisphenol-type epoxy resins, and biphenol-type epoxy resins are preferred, and bisphenol-type epoxy resins are more preferred, as they offer superior workability and yield cured products with excellent hardness and strength.

[0040] Examples of the bisphenol-type epoxy resins include bisphenol A type epoxy resin, bisphenol AP type epoxy resin, bisphenol B type epoxy resin, bisphenol BP type epoxy resin, bisphenol E type epoxy resin, bisphenol F type epoxy resin, and bisphenol S type epoxy resin.

[0041] Examples of the hydrogenated bisphenol type epoxy resins include hydrogenated bisphenol A type epoxy resin, hydrogenated bisphenol B type epoxy resin, hydrogenated bisphenol E type epoxy resin, hydrogenated bisphenol F type epoxy resin, and hydrogenated bisphenol S type epoxy resin.

[0042] Examples of the biphenol-type epoxy resins include 4,4'-biphenol-type epoxy resin, 2,2'-biphenol-type epoxy resin, tetramethyl-4,4'-biphenol-type epoxy resin, and tetramethyl-2,2'-biphenol-type epoxy resin.

[0043] Furthermore, when preparing using solid epoxy resin, although not particularly limited, it is preferable to use a method that involves using it in combination with liquid epoxy resin, or to liquefy it using a reactive or non-reactive diluent. When using a diluent, it is preferable to use a mixture of bisphenol-type epoxy resin and a reactive diluent.

[0044] The reactive diluent also contributes to improving the curing acceleration effect at low temperatures. Examples include alkyl glycidyl ethers such as phenyl glycidyl ether and butyl glycidyl ether, glycidyl esters of versatic acid, α-olefin epoxy, 1,6-hexanediol diglycidyl ether, neopentyl glycol diglycidyl ether, trimethylolpropane triglycidyl ether, methylphenol glycidyl ether, ethylphenol glycidyl ether, propylphenol glycidyl ether, and other alkylphenol glycidyl ethers. These may be used alone or in combination of two or more.

[0045] Among these reactive diluents, those containing epoxy groups are preferred, and furthermore, the alkylphenol glycidyl ether is preferred because it has low viscosity, can exert a diluting effect, and can increase the solid content of the composition (i.e., the solid content concentration in the composition is high, the solvent content is low, and the coating film can be made thicker with fewer coats).

[0046] The mixing ratio of the epoxy resin and the epoxy resin curing agent is such that a two-component curing type epoxy resin composition with excellent workability and excellent hardness and strength in the cured product is obtained. Therefore, it is preferable that the amount of active hydrogen in the curing agent is in the range of 0.5 to 1.5 equivalents, and more preferably in the range of 0.7 to 1.2 equivalents, per equivalent of epoxy groups in the epoxy resin.

[0047] The method for producing the epoxy resin composition is not particularly limited and can be any method. For example, the epoxy resin and the curing agent can be placed in a plastic container at room temperature (25°C) and stirred manually with a metal spatula or the like, or with an electric stirring device, until homogeneous.

[0048] Furthermore, the epoxy resin composition may contain other components as needed. Examples of these other components include inorganic fine particles, silane coupling agents, phosphate ester compounds, solvents, ultraviolet absorbers, antioxidants, silicone-based additives, fluorine-based additives, antistatic agents, organic beads, quantum dots (QDs), plasticizers, defoaming agents, anti-fogging agents, and colorants such as dyes and pigments.

[0049] Examples of the inorganic nanoparticles include silica, alumina, zirconia, titania, barium titanate, and antimony trioxide. These inorganic nanoparticles can be used individually or in combination of two or more types. Among these, silica particles are particularly versatile and come in various types, such as fumed silica, precipitated silica, gel silica, and sol-gel silica, but any of these can be used. Furthermore, the surface of the inorganic nanoparticles may be modified with a silane coupling agent or the like.

[0050] Examples of the silane coupling agents include (meth)acryloyloxy silane coupling agents such as [(meth)acryloyloxyalkyl]trialkylsilane, [(meth)acryloyloxyalkyl]dialkylalkoxysilane, [(meth)acryloyloxyalkyl]alkyldialkoxysilane, and [(meth)acryloyloxyalkyl]trialkoxysilane; vinyl silane coupling agents such as trialkylvinylsilane, dialkylalkoxyvinylsilane, alkyldialkoxyvinylsilane, trialkoxyvinylsilane, trialkylallylsilane, dialkylalkoxyallylsilane, alkyldialkoxyallylsilane, and trialkoxyallylsilane; styrene silane coupling agents such as styryltrialkyl, styryldialkylalkoxysilane, styrylalkyldialkoxysilane, and styryltrialkoxysilane; and (glycidyloxyalkyl)trial Examples of epoxy silane coupling agents include sylsilane, (glycidyloxyalkyl)dialkylalkoxysilane, (glycidyloxyalkyl)alkyldialkoxysilane, (glycidyloxyalkyl)trialkoxysilane, [(3,4-epoxycyclohexyl)alkyl]trimethoxysilane, [(3,4-epoxycyclohexyl)alkyl]trialkylsilane, [(3,4-epoxycyclohexyl)alkyl]dialkylalkoxysilane, [(3,4-epoxycyclohexyl)alkyl]alkyldialkoxysilane, and [(3,4-epoxycyclohexyl)alkyl]trialkoxysilane; and isocyanate silane coupling agents include (isocyanate alkyl)trialkylsilane, (isocyanate alkyl)dialkylalkoxysilane, (isocyanate alkyl)alkyldialkoxysilane, and (isocyanate alkyl)trialkoxysilane. These silane coupling agents can be used alone or in combination of two or more.

[0051] Examples of the aforementioned phosphate ester compounds include commercially available products such as "Kayama PM-2" and "Kayama PM-21" from Nippon Kayaku Co., Ltd., which are phosphate ester compounds having a (meth)acryloyl group in their molecular structure; "Light Ester P-1M," "Light Ester P-2M," and "Light Acrylate P-1A(N)" from Kyoeisha Chemical Co., Ltd.; "Sipomer PAM 100," "Sipomer PAM 200," "Sipomer PAM 300," and "Sipomer PAM 4000" from SOLVAY, Inc.; "Viscote #3PA" and "Viscote #3PMA" from Osaka Organic Chemical Industry Co., Ltd.; and "New Frontier S-23A" from Daiichi Kogyo Seiyaku Co., Ltd.; as well as "Sipomer PAM 5000" from SOLVAY, Inc., which is a phosphate ester compound having an allyl ether group in its molecular structure.

[0052] The aforementioned solvent is added for purposes such as adjusting the coating viscosity of the epoxy resin composition, and its type and amount are appropriately adjusted according to the desired performance. Examples of the aforementioned solvent include ketone solvents such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; cyclic ether solvents such as tetrahydrofuran and dioxolane; esters such as methyl acetate, ethyl acetate, and butyl acetate; aromatic solvents such as toluene and xylene; and alicyclic solvents such as cyclohexane and methylcyclohexane. These solvents can be used individually or in combination of two or more.

[0053] Examples of the aforementioned UV absorbers include triazine derivatives such as 2-[4-{(2-hydroxy-3-dodecyloxypropyl)oxy}-2-hydroxyphenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine and 2-[4-{(2-hydroxy-3-tridecyloxypropyl)oxy}-2-hydroxyphenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, 2-(2'-xanthenecarboxy-5'-methylphenyl)benzotriazole, 2-(2'-o-nitrobenzyloxy-5'-methylphenyl)benzotriazole, 2-xanthenecarboxy-4-dodecyloxybenzophenone, and 2-o-nitrobenzyloxy-4-dodecyloxybenzophenone. These UV absorbers can be used alone or in combination of two or more.

[0054] Examples of the aforementioned antioxidants include hindered phenol antioxidants, hindered amine antioxidants, organosulfur antioxidants, and phosphate ester antioxidants. These antioxidants can be used individually or in combination of two or more.

[0055] Examples of the aforementioned silicon-based additives include polyorganosiloxanes having alkyl or phenyl groups, such as dimethylpolysiloxane, methylphenylpolysiloxane, cyclic dimethylpolysiloxane, methylhydrogenpolysiloxane, polyether-modified dimethylpolysiloxane copolymer, polyester-modified dimethylpolysiloxane copolymer, fluorine-modified dimethylpolysiloxane copolymer, and amino-modified dimethylpolysiloxane copolymer; polydimethylsiloxane having polyether-modified acrylic groups; and polydimethylsiloxane having polyester-modified acrylic groups. These silicon additives can be used individually or in combination of two or more types.

[0056] Examples of the aforementioned fluorine-based and silicon-based additives include the "Megaface" series manufactured by DIC Corporation.

[0057] Examples of the antistatic agents include pyridinium, imidazolium, phosphonium, ammonium, or lithium salts of bis(trifluoromethanesulfonyl)imide or bis(fluorosulfonyl)imide. These antistatic agents can be used individually or in combination of two or more.

[0058] Examples of the organic beads include polymethyl methacrylate beads, polycarbonate beads, polystyrene beads, polyacrylic styrene beads, silicone beads, glass beads, acrylic beads, benzoguanamine resin beads, melamine resin beads, polyolefin resin beads, polyester resin beads, polyamide resin beads, polyimide resin beads, polyfluoroethylene resin beads, polyethylene resin beads, and the like. These organic beads can be used individually or in combination of two or more types. The average particle size of these organic beads is preferably in the range of 1 to 10 μm.

[0059] Examples of the aforementioned plasticizers include polybasic acid esters such as dioctyl phthalate, dibutyl phthalate, and dioctyl adipicate; polyhydric alcohol esters such as diethylene glycol dibenzoate, diethylene glycol dioctoate, and glycerol triptylate; epoxidized esters such as octyl 9,10-epoxystearate, epoxidized vegetable oil, and dioctyl 4,5-epoxyhexahydrophthalate; and phosphate esters such as triphenyl phosphate, trioctyl phosphate, and diphenyl monoisopropyl phosphate.

[0060] Examples of the aforementioned dyes and pigments include titanium dioxide, carbon black, iron oxide, lead yellow, disazo yellow, quinophthalone yellow, monoazo red, benzoimidazoline red, and phthalocyanine blue.

[0061] These various additives can be added in any amount depending on the desired performance, but it is generally preferable to use them in the range of 0.01 to 40 parts by mass per 100 parts by mass of nonvolatile content of the epoxy resin composition.

[0062] The epoxy resin composition of the present invention can be used in a variety of fields, including adhesives, paints, and linings / flooring materials. It is particularly suitable as a lining agent due to its excellent curing properties and workability at low temperatures. It can also be used as a molded product (casting resin) in the manufacture of tools. In addition, it can be used for coating various types of substrates, such as wood, wood fiber materials (wood sealing), natural or synthetic fabrics, plastics, glass, ceramics, concrete, fiberboard, and artificial stone, as well as metals. These coatings can be applied by brush, spray, dipping, or other methods. Furthermore, it can be used as an adhesive, putty, or laminating resin. When the epoxy resin composition of the present invention is solvent-free, curing occurs at temperatures between -10°C and +50°C, preferably between 0°C and 40°C. For example, a cured product with excellent strength can be obtained at a low temperature of around 5°C, after 8 to 24 hours at 50% relative humidity in the atmosphere, or after 1 to 4 hours at room temperature. [Examples]

[0063] The present invention will be specifically described below with reference to examples and comparative examples. However, the present invention is not limited to the examples listed below.

[0064] Synthesis Example 1 [Synthesis of Condensate (A1)] In a 1L container equipped with a thermometer, a stirrer, and a condenser for dehydration condensation, 136g (1 mol) of metaxylenediamine and 94g (1 mol) of phenol were charged and thoroughly stirred. Then, 72g of 41.5% formalin was added dropwise over 0.5 hours. The temperature was further raised to 100°C and the reaction was allowed to proceed for 2 hours, after which dehydration was performed to obtain the condensate (A1). The condensate (A1) was non-fluid and in a solid state at room temperature. The active hydrogen equivalent of the solid content of the condensate (A1) was 99g / equivalent. When the condensate (A1) was adjusted to an 80% solid solution with benzyl alcohol, the viscosity was 3500 mPa·s (BM type rotational viscometer, 25°C).

[0065] Synthesis Example 2 [Synthesis of Condensate (A2)] 136 g (1 mole) of metaxylenediamine and 150 g (1 mole) of para-t-butylphenol were charged into a 1 L container equipped with a thermometer, a stirrer, and a condenser for dehydration condensation. The mixture was heated to 40°C and stirred thoroughly until the liquid dissolved clearly. Then, 72 g of 41.5% formalin was added dropwise over 0.5 hours. The temperature was further increased to 140°C and the reaction was allowed to proceed for 2 hours. After dehydration, the condensate (A2) was obtained. The condensate (A2) was solid and non-fluid at room temperature. The active hydrogen equivalent of the solid content of the condensate (A2) was 118 g / equivalent. When the condensate (A2) was adjusted to an 80% solid solution with benzyl alcohol, the viscosity was 6000 mPa·s (BM type rotational viscometer, 25°C).

[0066] The preparation of the epoxy resin curing agent and the raw materials used in the composition are as follows. Epoxy resin 1: Bisphenol A type liquid epoxy resin (DIC Corporation's "EPICLON 850", epoxy equivalent weight 188g / equivalent) Petroleum resin (B): Nippon Oil Neopolymer 120 (manufactured by ENEOS Material Co., Ltd.) Hydrocarbon solvent (C): Benzyl alcohol (manufactured by Hubei Greenhome Fine Chemical Co., LTD.) Compound (D): 2,4,6-Tris(dimethylaminomethyl)phenol (ANCAMINER K54, manufactured by Evonik Japan Co., Ltd.) Amine component A3: 1,3-bisaminomethylcyclohexane ("1,3BAC" manufactured by Mitsubishi Gas Chemical Company, Inc., active hydrogen equivalent 35.5 g / equivalent) Amine component A4: Benzylamine (Benzylamine manufactured by Koei Chemical Industry Co., Ltd., active hydrogen equivalent 53.5g / equivalent) Amine component A5: Hardener OH-802 (aliphatic polyamine, manufactured by Chori Greggs Co., Ltd., active hydrogen equivalent 50g / equivalent) Xylene resin: Manufactured by Fudo Co., Ltd., "Nikanol G" PTBP: Para-t-butylphenol (manufactured by Rachem (China) Co., Ltd.)

[0067] Examples 80g of benzyl alcohol was placed in a 1L container equipped with a thermometer, stirrer, and condenser, and the temperature was raised to 80°C while stirring. 80g of Nisseki Neopolymer 120 was prepared, and 16g (one-fifth of the total) was placed in the container. The container was held until dissolution was visually confirmed. This procedure was repeated for the remaining four divisions, until a total of 80g was completely dissolved. 296g of the condensate (A1), preheated to 80°C, was added and held until dissolution was confirmed. While continuing to stir, 80g of PTBP was added. The temperature setting was released and the mixture was held until dissolution was visually confirmed. 16g of 1,3-bisaminomethylcyclohexane, 120g of hardener OH-802, 48g of benzylamine, and 80g of 2,4,6-Tris(dimethylaminomethyl)phenol were added in that order and held until the solution was completely dissolved. Stirring was stopped and the mixture was transferred to a container. Similarly, epoxy resin curing agents were prepared using each component in the proportions (by mass) shown in Tables 1 and 2. The viscosity and number of colors of the obtained curing agents were measured using the methods described below, and the results are shown in the table.

[0068] [Method for measuring viscosity] A 100g sample was placed in a 100cc glass bottle and immersed in a 25°C constant temperature water bath for 3 hours. A BM-type rotational viscometer, fitted with a predetermined rotor, was attached to the constant temperature water bath and rotated at a predetermined speed for 3 minutes. The displayed value was read and defined as viscosity.

[0069] [Method for measuring the number of colors] The sample was placed in a glass screw tube for Gardner viscosity measurement, and the Gardner color number of the test specimen was measured using a color analyzer.

[0070] [Table 1]

[0071] [Table 2]

[0072] The epoxy resin curing agent and epoxy resin obtained above were cured for at least one day under constant temperature and humidity conditions of 5°C and 50% humidity in a controlled room. In the same room, the epoxy resin curing agent and epoxy resin were weighed into plastic containers to the specified proportions. The mixture was manually stirred for one minute using a metal spatula or the like, and the degree of homogenization in the container was visually observed and evaluated according to the following evaluation criteria.

[0073] [Method for measuring Shore D hardness] Samples prepared under the above environmental conditions were poured into aluminum petri dishes with a diameter of 30 mm and a height of 10 mm to prepare test specimens. Curing periods were set to 16 hours and 24 hours. Test specimens were measured using a durometer hardness tester type D, and the maximum value was read.

[0074] [Evaluation method after water droplets are dropped] 22.5g of the sample, prepared under the above environmental conditions, was uniformly applied to a slate board (size 150mm x 150mm) using a metal spatula to prepare a test specimen (application amount 1kg / m²). 2 The samples were cured in the same room, and 1.5g of pure water was spotted onto the test plate after 1 and 2 days. After 7 days of curing, the test specimens were visually observed and evaluated according to the following criteria. ○: No water droplet marks, △: Slight water droplet marks, ×: Large water droplet marks

[0075] [Method for measuring gloss] After curing the test specimens prepared according to the above [Evaluation Method after Water Droplet] for 7 days, the specimens were removed and the gloss (measurement angles: 20°, 60°, 85°) of areas without water droplet marks was measured using a gloss meter (manufactured by Nippon Denshoku Industries Co., Ltd., gloss meter VG-7000).

[0076] [Table 3]

[0077] [Table 4]

Claims

1. An amine compound (a) having at least two primary amino groups in one molecule, Formaldehyde (b) and A phenol compound (c) which may have an alkyl group having 1 to 12 carbon atoms, Condensate (A), Petroleum resin (B), which is a C5-9 aromatic hydrocarbon fraction polymer. Hydrocarbon solvents (C) with a boiling point of 150°C or higher, Compounds having a tertiary amino group (D) It contains as an essential ingredient, The mass ratio of each of the above components is, Condensate (A) / Petroleum resin (B) = 1 to 10, Petroleum resin (B) / Hydrocarbon solvent (C) = 0.5 to 2.0 Condensate (A) / Compound (D) = 1.5 to 4.5 Epoxy resin hardeners within this range.

2. The epoxy resin curing agent according to claim 1, wherein the viscosity at 25°C is in the range of 100 to 1,000 mPa·s.

3. The epoxy resin curing agent according to claim 1, wherein the amine compound (a) is an aliphatic polyamine containing an aromatic ring.

4. The epoxy resin curing agent according to claim 1, wherein the hydrocarbon solvent (C) is benzyl alcohol or phenylxylethane.

5. The epoxy resin curing agent according to claim 1, wherein the content of the petroleum resin (B) is 5 to 20 parts by mass in a total of 100 parts by mass of the condensate (A), the petroleum resin (B), the hydrocarbon solvent (C), and the compound (D).

6. An epoxy resin composition comprising an epoxy resin curing agent according to any one of claims 1 to 5 and an epoxy resin.

7. The epoxy resin composition according to claim 6, wherein the amount of active hydrogen in the curing agent is in the range of 0.5 to 1.5 equivalents per equivalent of epoxy groups in the epoxy resin.

8. A cured product of the epoxy resin composition according to claim 6.

9. A lining agent containing the epoxy resin composition described in claim 6.

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