JP2013072073A - Amine-based curing agent, epoxy resin composition containing amine-based curing agent, and cured product of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a curing agent used for an epoxy resin, which is excellent in water dispersibility, excellent in emulsion stability, storage stability, and drying properties after coating for the epoxy resin, and further capable of giving a cured product excellent in strength of a coating film and corrosion resistance; an epoxy resin composition containing the curing agent; and a cured product which has water resistance and alkali resistance and is excellent in strength of a coating film and corrosion resistance.SOLUTION: The amine-based curing agent comprises an aromatic diamine adduct of an epoxy resin having an alkyl (polyoxyalkylene) group in a side chain which is obtained by the reaction of: a modified epoxy resin obtained by the reaction of an epoxy resin having at least two epoxy groups in one molecule and an alkyl(polyoxyalkylene) amine compound; and an aromatic diamine.

Description

  The present invention relates to a curing agent used for an epoxy resin composition useful for paints, adhesives, fiber sizing agents, concrete primers, and the like, and an epoxy resin composition containing the curing agent. The present invention relates to a curing agent used for an epoxy resin composition capable of imparting corrosion resistance and adhesion of a processed product without impairing the storage stability of the varnish, and an epoxy resin composition containing the curing agent.

  An epoxy resin composition comprising an epoxy resin and a curing agent has many excellent properties such as adhesion to various substrates, heat resistance, chemical resistance, electrical properties, mechanical properties, Awarded in the field of paints and adhesives. When used in the above applications, conventional solvent types using various organic solvents have been common, but there are only fire hazards, harm to humans, and cost increases due to the use of solvents. However, the use of organic solvents has been restricted due to the problem of adverse effects on the global environment.

  For this reason, in recent years, aqueous epoxy resin compositions that do not use organic solvents have come to the spotlight. This aqueous epoxy resin composition is obtained by dispersing or dissolving an epoxy resin and a curing agent in water, and generally employs a method of emulsifying and dispersing using a surfactant.

  However, the aqueous epoxy resin composition emulsified using the surfactant as described above may not only be inferior in storage stability depending on the type and amount of the surfactant, but also from the aqueous epoxy resin composition. The obtained cured product tends to be inferior in physical properties of the cured product as compared to the case of using a solvent-based composition, and in particular, has poor defects in anticorrosion properties due to poor water resistance and adhesion. These disadvantages are thought to be due to the adverse effect of the surfactant remaining in the cured product. By using a self-emulsifying compound as the curing agent, an aqueous epoxy resin composition without using a surfactant. It has been proposed to produce things.

  For example, Patent Document 1 below proposes the use of a reaction product of an adduct of a polyalkylene polyol and an excess equivalent amount of polyepoxide and an organic polyamine as a curing agent, and Patent Document 2 listed below discloses a polyalkylene polyol and a lactone. It has also been proposed to use a reactant of an excess equivalent of a polyepoxide and an organic polyamine as a curing agent.

Japanese Patent Publication No. 61-40688 JP-A-4-351628

  However, since the curing agents described in these patent documents contain large hydrophobic groups in the molecule, the resulting aqueous epoxy resin composition tends to have poor storage stability and improves storage stability. Therefore, it is necessary to use a relatively high molecular weight polyether polyol. However, when a high molecular weight polyether polyol is used, the corrosion resistance of the cured product is inferior, which is not satisfactory in practice.

  It has also been proposed to use a polyamine compound having a polyether bond in the molecule or a modified product thereof as a curing agent, but these compounds have a polyoxypropylene group as a polyether chain or have a low degree of polymerization. It is a compound having a polyoxyethylene chain, and since these compounds themselves are insoluble in water, they do not become self-emulsifying type curing agents, or even if these compounds themselves are water soluble, When polyamine is used or modified, the solubility in water decreases, so there is a drawback that the storage stability of the aqueous epoxy resin composition and the drying property after coating are insufficient, and its curing There was a defect that the physical properties of the material were insufficient, and the anticorrosion property was particularly inferior.

  The problem to be solved by the present invention is to obtain a cured product having excellent water dispersibility, emulsion stability with respect to an epoxy resin, storage stability, excellent drying property after coating, and excellent coating strength and corrosion resistance. Another object of the present invention is to provide a curing agent used for an epoxy resin, an epoxy resin composition containing the curing agent, and a cured product having water resistance and alkali resistance and excellent in coating strength and corrosion resistance.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that this curing can be achieved by using an amine-based curing agent composed of an aromatic diamine adduct of a bifunctional epoxy resin having a polyethylene glycol chain introduced in the side chain. The epoxy resin composition containing an agent can be made water-based, and can increase the crosslinking density at the time of curing, and as a result, the corrosion resistance of the cured product is improved, thereby completing the present invention. It came.

  That is, in order to solve the above-mentioned problems, the present invention (1) reacts an epoxy resin (A) having two or more epoxy groups in one molecule with an alkyl (polyoxyalkylene) amine compound (B). It consists of an aromatic diamine adduct of an epoxy resin having an alkyl (polyoxyalkylene) group in the side chain obtained by reacting the resulting modified epoxy resin (I) with an aromatic diamine (II). An amine curing agent is provided.

In order to solve the above-mentioned problems, the present invention (2) reacts an epoxy resin (A) having two or more epoxy groups in one molecule with an alkyl (polyoxyalkylene) amine compound (B). , A first step of producing a modified epoxy resin (I) having an alkyl (polyoxyalkylene) group in the side chain;
It comprises an aromatic diamine adduct of an epoxy resin having an alkyl (polyoxyalkylene) group in the side chain, which has a second step of reacting the modified epoxy resin (I) with an aromatic diamine (II). A method for producing an amine curing agent is provided.

  Furthermore, in order to solve the above-mentioned problems, the present invention comprises (3) the epoxy resin (I) described in (1) above and the amine curing agent described in (1) above. I will provide a.

  Furthermore, in order to solve the above problems, the present invention includes (4) the epoxy resin (I) described in (1) above, the amine-based curing agent described in (1) above, and an aqueous solvent. An epoxy resin composition is provided.

  Furthermore, in order to solve the above-mentioned problems, the present invention provides (5) a cured product obtained by curing the epoxy resin composition described in (3).

  The amine-based curing agent of the present invention is excellent in water dispersibility by being used as a curing agent for an epoxy resin, excellent in emulsion stability, storage stability, and drying property after coating, and further obtained cured product Has water resistance and alkali resistance, and is excellent in coating film strength and corrosion resistance. In particular, the amine-based curing agent of the present invention is excellent in water solubility and emulsion stability as well as water resistance and alkali resistance by being used as a curing agent for an epoxy resin having a polyethylene glycol monoalkyl ether residue in the side chain. A cured product having excellent corrosion resistance and coating strength can be provided.

FIG. 1 is a GPC chart of the water-dispersible amine-based curing agent (1) obtained in Example 1. FIG. 2 is an IR spectrum of the water-dispersible amine curing agent (1) obtained in Example 1.

  The amine curing agent of the present invention is obtained by reacting an epoxy resin (A) having two or more epoxy groups in one molecule with an alkyl (polyoxyalkylene) amine compound (B) to form an alkyl (polyalkylene) on the side chain. It can be produced by a first step of producing a modified epoxy resin (I) having an oxyalkylene) group, a second step of reacting the modified epoxy resin (I) with an aromatic diamine (II).

  As the epoxy resin (A), a known epoxy resin can be used. Examples of such an epoxy resin (A) include an epoxy resin obtained from epichlorohydrin or β-methylepichlorohydrin and bisphenol A, bisphenol F or bisphenol sulfone; a polyglycidyl ether of a phenol novolac resin or a cresol novolac resin; Polyglycidyl ethers of alkylene oxide adducts; polyglycidyl ethers of polyhydric alcohols such as polypropylene glycol, 1,6-hexanediol, trimethylolpropane and glycerin; polyglycidyls of polycarboxylic acids such as adipic acid, phthalic acid and dimer acid Ester; Polyglycidylamine, these epoxy resins can be used as polyphenols such as bisphenol A and bisphenol F, or Epoxy resin be those modified with polycarboxylic acids, such as pins acid and sebacic acid, and the like. Among these, an epoxy resin obtained from epichlorohydrin and a phenol compound having two hydroxyl groups in the molecule, specifically, an epoxy resin obtained from bisphenol A or bisphenol F and epichlorohydrin is more preferable. Among these epoxy resins, those having an epoxy equivalent in the range of 150 to 200 are preferable.

  The alkyl (polyoxyalkylene) amine compound (B) used in the present invention is preferably an alkylene having 2 to 4 carbon atoms in the polyoxyalkylene chain, specifically 1,2-ethylene, 1,2 -Propylene, 1,2-butylene and the like. Further, the terminal alkyl group is preferably an alkyl group having 1 to 4 carbon atoms, and particularly preferably a methyl group.

  Specifically, the alkyl (polyoxyalkylene) amine compound (B) used in the present invention is represented by the general formula (B-1).

(In the formula, n is an integer of 2 to 100, a plurality of R's independently represent —CH ₂ —CHR ² — or —CHR ² —CH ₂ —, R ¹ represents an alkyl group, R ² Represents a hydrogen atom or an alkyl group, and R ³ represents a hydrogen atom or an alkyl group.)
Or a compound represented by the general formula (B-2)

(In the formula, p and q are each independently an integer of 2 to 90, and the upper limit of the sum of p and q is 100, and R ¹ represents an alkyl group.)
The compound represented by these is mentioned.

  The number average molecular weight of the polyoxyalkylene chain in the alkyl (polyoxyalkylene) amine compound (B) is preferably 400 to 3000, and particularly preferably 1000 to 2000. By using a material in such a range, both the water solubility and emulsion stability of the epoxy resin composition according to claim 10 and the water resistance, corrosion resistance, and coating strength of the cured product according to claim 16 are achieved. Since there exists a tendency which is excellent in the balance of performance, it is preferable.

The alkyl (polyoxyalkylene) amine compound (B) is commercially available. Specifically, “Jeffamine M-600” (manufactured by Texaco Chemical Co., Ltd., in the above general formula (B-2), R ¹ is a methyl group, p: q = 9: 1 (molar ratio), weight average molecular weight 600 ), “Jeffamine M-1000” (manufactured by Texaco Chemical Co., Ltd., in the above general formula (B-2), R ¹ is a methyl group, p: q = 3: 19 (molar ratio), weight average molecular weight 1000), “ “Jeffamine M-2005” (manufactured by Texaco Chemical Co., Ltd., in the above general formula (B-2), R ¹ is a methyl group, p: q = 29: 6 (molar ratio), weight average molecular weight 2,000), “Jeffer Min M-2070 ”(manufactured by Texaco Chemical Co., Ltd., in the general formula (B-2), R ¹ is a methyl group, p: q = 10: 31 (molar ratio), weight average molecular weight 2,000), and the like. . Among these, “Jeffamine M-600” and “Jeffamine M-2070” are particularly preferable.

  The modified epoxy resin (I) having an alkyl (polyoxyalkylene) group in the side chain used in the present invention includes an epoxy resin (A) having two or more epoxy groups in one molecule and an alkyl (polyoxyalkylene) amine. Obtained by reacting with compound (B).

  The ratio of these compounds in the reaction between the epoxy resin (A) and the compound (B) is such that the epoxy resin (A) is not less than 1.5 mol and not more than 2.5 mol per mol of the compound (B). The range is preferable, and the range of 1.8 mol to 2.2 mol is particularly preferable. When the proportion of the epoxy resin (A) is less than 1.5 mol, the molecular weight of the resulting modified epoxy resin (I) having an alkyl (polyoxyalkylene) group is increased, resulting in viscosity or poor solubility. This is not preferable. Moreover, when the ratio of the said epoxy resin (A) exceeds 2.5 mol, since there exists a tendency for unreacted epoxy resin (A) to increase and water solubility to fall, it is unpreferable.

  Moreover, a catalyst can be used for reaction of the said epoxy resin (A) and the said compound (B). Examples of such catalysts include tertiary amines such as triethylamine, tributylamine, benzyldimethylamine, 2,4,6-tris (dimethylaminomethyl) phenol, N-methylpiperazine, and salts thereof; 2-methyl Imidazole, 2-phenylimidazole, 2-undecylimidazole, 2-ethyl-4-methylimidazole, 1-cyanoethyl-2-methylimidazole, 2,4-dicyano-6- [2-methylimidazolyl-1] -ethyl- Imidazoles such as S-triazine, 2-ethyl-4-methylimidazole tetraphenylborate, and salts thereof; 1,5-diazabicyclo [5,4,0] -7-undecane, 1,5-diazabicyclo [4, 3,0] -5-nonene, 1,4-diabicyclo [2,2,2, Diazabicyclo compounds such as octane, 1,8-diazabicyclo [5.4.0] undecene-7-tetraphenylborate; tributylphosphine, triphenylphosphine, tris (dimethoxyphenyl) phosphine, tris (hydroxypropyl) phosphine, tris ( Phosphines such as cyanoethyl) phosphine; phosphonium salts such as tetraphenylphosphonium salt, methyltributylphosphonium salt, methyltricyanoethylphosphonium salt and tetrabutylphosphonium salt. Among these catalysts, phosphonium salts having no benzene ring in the molecule are most preferred because they are difficult to color. The use ratio when using the catalyst is preferably in the range of 0.01 to 5 parts by mass with respect to 100 parts by mass of the epoxy resin (B). The reaction temperature is preferably in the range of 70 to 170 ° C, particularly preferably in the range of 80 to 120 ° C. The reaction time is preferably in the range of 3 to 10 hours, particularly preferably in the range of 3 to 8 hours.

  The epoxy equivalent of the modified epoxy resin (I) having an alkyl (polyoxyalkylene) group in the side chain obtained by the reaction between the epoxy resin (A) and the compound (B) is 600 to 6000 [g / eq]. The range is preferable, and the range of 900 to 2500 [g / eq] is particularly preferable. If the epoxy equivalent is 600 [g / eq] or more, the water dispersibility tends to be improved, and if it is 6000 [g / eq] or less, the water resistance tends to be improved.

  In the aromatic diamine adduct of the epoxy resin (I) obtained by reacting the epoxy resin (I) with the aromatic diamine (II), the epoxy group in the epoxy resin (I) is converted to an aromatic diamine (II). It can be easily produced by reacting at a ratio such that all amino groups are consumed by the reaction with the amino group in () and the amino groups remain at both ends of the molecule. The ratio of the epoxy resin (I) and the aromatic diamine (II) is preferably such that the aromatic diamine (II) is 2 to 5 equivalents with respect to 1 equivalent of the epoxy resin (I). In addition, the reaction is carried out by adding the epoxy resin (I) to the aromatic diamine (II) while heating to 70 to 90 ° C., dropwise or in 3 to 5 portions, and then the same temperature or the same temperature. Can be produced by aging at a temperature of 20 to 40 ° C. for 2 to 4 hours.

  Examples of the aromatic diamine (II) include 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenyl ether, o-xylenediamine, m-xylenediamine, p-xylenediamine, toluylenediamine, 2,2- And bis [4- (4-aminophenoxy) phenyl] propane. These can be used alone or in combination of two or more. Among these aromatic diamines, aralkylenediamines such as o-xylenediamine, m-xylenediamine, and p-xylenediamine are preferable, and m-xylenediamine is particularly preferable.

  The amine-based curing agent of the present invention obtained as described above has, for example, a general formula

(Wherein, n is an integer of 2 to 100, -CH ₂ -CHR ² are each a plurality of R independently - or -CHR ² -CH ₂ - represents, ^{R 1} represents an alkyl group, preferably a carbon atom represents the number 1-3 alkyl group, R ² represents a hydrogen atom or an alkyl group, preferably an alkyl group having 1 to 3 carbon atoms, R ³ is a hydrogen atom or an alkyl group, preferably from 1 to 3 carbon atoms Represents an alkyl group of
A compound represented by the formula

Wherein p and q are each independently an integer of 2 to 90, and the upper limit of the sum of p and q is 100, and R ¹ represents an alkyl group, preferably an alkyl group having 1 to 3 carbon atoms. .)
A compound represented by the formula is particularly preferred.

  The epoxy resin composition of the present invention contains the epoxy resin (I), the amine-based curing agent, and, if necessary, an epoxy resin (I ′) other than the epoxy resin (I). Although this epoxy resin composition can be dissolved or dispersed in an aqueous solvent in advance, it is desirable to dissolve or disperse in an aqueous solvent immediately before use as a coating material. In particular, by mixing the epoxy resin (I) and an epoxy resin (I ′) other than the epoxy resin (I), a water-soluble epoxy resin composition exhibiting self-emulsifying properties in an aqueous solvent is obtained. it can.

  As the epoxy resin (I ′) other than the epoxy resin (I), the epoxy resin (A) can be used, and among these, an epoxy resin obtained from epichlorohydrin and bisphenol A and / or bisphenol F and Phenol novolak resins and polyglycidyl ethers of cresol novolak resins are particularly preferred.

  When the epoxy resin (I) and the epoxy resin (I ′) other than the epoxy resin (I) are used in combination, the former is 5 to 70 parts by mass and the latter is 95 to 30 parts by mass. The former is 10 to 50 parts by mass, and the latter is particularly preferably 90 to 50 parts by mass. By mixing at such a ratio, the epoxy resin composition of the present invention exhibits excellent dispersibility in an aqueous solvent. When the ratio of the epoxy resin (I) is 5 parts by mass or more, the emulsion stability is good, and when it is 70 parts by mass or less, the water resistance of the cured product becomes good.

  The aqueous solvent may be water itself or a mixture of a water-soluble solvent and water. The water-soluble solvent is not particularly limited as long as it is uniformly mixed with water and can dissolve or disperse the epoxy resin and the amine curing agent and is inert to these. For example, esters such as ethyl acetate, 3-methoxybutyl acetate, methoxypropyl acetate, cellosolve acetate; alcohols such as methanol, ethanol, isopropanol; methyl cellosolve, ethyl cellosolve, propyl cellosolve, butyl cellosolve, isobutyl cellosolve, tert- Cellosolves such as butyl cellosolve; glymes such as monoglyme, diglyme and triglyme; propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monobutyl ether, propylene Glycol monoisobutyl ether, such as propylene glycol monoalkyl ethers and propylene glycol monomethyl tert- butyl ether; acetone, include such ketones methyl ethyl ketone. Among these, cellosolves, propylene glycol monoalkyl ethers, and ketones are preferable, and ketones are particularly preferable.

  The mixing ratio of the epoxy resin and the aqueous solvent in the composition of the present invention is preferably in the range of epoxy resin / aqueous solvent = 10 to 99/90 to 1 (mass ratio), and 50 to 99/50 to 1 (mass ratio). ) Is particularly preferred.

  In the epoxy resin composition of the present invention, other conventionally known basic curing agents can be used in combination with the amine curing agent as long as the characteristics thereof are not deteriorated. Examples of other basic curing agents that can be used in combination include aliphatic polyamines, alicyclic polyamines, Mannich bases, amine-epoxy addition products, polyamide polyamines, and liquid aromatic polyamines.

  Examples of the aliphatic polyamine used as the basic curing agent include polyalkylene polyamines such as diethylenetriamine, triethylenetriamine, tetraethylenepentamine, 1,4-bis- (3-aminopropyl) piperazine, m-xylenediamine, Examples include p-xylenediamine.

  Examples of the alicyclic polyamine used as the basic curing agent include 1,2-diaminocyclohexane, 1,4-diamino-3,6-diethylcyclohexene, isophoronediamine and the like.

  Mannich bases used as basic curing agents include: (1) polyamines such as triethylenetriamine, isophoronediamine, m-xylenediamine, and p-xylenediamine; (2) aldehydes such as formaldehyde; Examples thereof include condensation reaction products with monovalent or polyvalent cresols and xylenols having at least one aldehyde reactive site in the nucleus, and phenols such as p-tert-butylphenol and resorcin.

  Examples of amine-epoxy addition products used as basic curing agents include (1) (a) polyamines such as triethylenetriamine, tetraethylenepentamine, isophoronediamine, m-xylenediamine, and p-xylenediamine. (B) reaction products with epoxy resins such as glycidyl ethers such as phenyl glycidyl ether, butyl glycidyl ether, diglycidyl ether of bisphenol A, diglycidyl ether of bisphenol F, or (2) the polyamines, A reaction product with glycidyl esters such as “Cardura E” (registered trademark: Yuka Shell Epoxy Co., Ltd.) can be mentioned.

  As the polyamide polyamine used as the basic curing agent, those obtained by the reaction of polyamines with polycarboxylic acids or dimerized fatty acids can be used, for example, reaction products of ethylenediamine and dimer acid, etc. Can be mentioned.

  Examples of the liquid aromatic polyamine used as the basic curing agent include a reaction product of an aromatic polyamine and glycidyl ethers or glycidyl esters. Examples of the aromatic polyamine include diaminodiphenylmethane and diaminodiphenylsulfone. Examples of the glycidyl ethers include phenyl glycidyl ether, butyl glycidyl ether, diglycidyl ether of bisphenol A, diglycidyl ether of bisphenol F, and the like. Examples of glycidyl esters include “Cardura E”.

  The proportion of the amine curing agent used in the composition of the present invention is such that the ratio of the epoxy equivalent in the epoxy resin to the amine equivalent in the curing agent (epoxy equivalent / amine equivalent) is in the range of 0.75 to 1.25. preferable.

  The epoxy resin composition of the present invention can be cured at room temperature or low temperature.

  Since the amine curing agent of the present invention and the epoxy resin (I) used in the present invention have a hydrophilic group in the side chain, they are excellent in water solubility. In addition, since the epoxy resin (I) used in the present invention has an epoxy group in the molecule, it exhibits affinity with other epoxy compounds and can be used as a dispersant, and is self-emulsified in an aqueous solvent. Excellent water dispersibility.

  The epoxy resin composition of the present invention and the emulsion composition obtained by emulsifying the same can be produced by any known method. Moreover, the obtained emulsion composition etc. can be used by a conventionally well-known suitable method.

  The epoxy resin composition of the present invention may be used in combination with other resin components such as other polyester-based water-based resins and acrylic water-based resins, as long as the characteristics are not impaired.

  In addition, the epoxy resin composition of the present invention may contain various additives such as anti-repellent agents, anti-sagging agents, spreading agents, antifoaming agents, curing accelerators, ultraviolet absorbers, and light stabilizers as necessary. It can also be blended.

  Although it does not restrict | limit especially as an application of the epoxy resin composition of this invention, For example, a coating material, an adhesive agent, a fiber sizing agent, a concrete primer etc. are mentioned.

  When the epoxy resin composition of the present invention is used for coating applications, it is preferable to blend various pigments such as rust preventive pigments, colored pigments, extender pigments, various additives, and the like as necessary. Examples of the antirust pigment include scaly pigments such as zinc powder, aluminum phosphomolybdate, zinc phosphate, aluminum phosphate, barium chromate, aluminum chromate, and graphite. Examples of the color pigment include Carbon black, titanium oxide, zinc sulfide, bengara, and extender pigments include, for example, barium sulfate, calcium carbonate, talc, kaolin, and the like. As these compounding quantities, it is 10-70 mass parts with respect to a total of 100 mass parts of an epoxy resin composition and the hardening | curing agent mix | blended as needed, points, such as coating-film performance and coating workability | operativity To preferred.

  The coating method when the epoxy resin composition of the present invention is used for coating is not particularly limited, and can be performed by roll coating, spraying, brush, spatula, bar coater, dip coating, or electrodeposition coating method. . As a post-treatment method after coating, room temperature drying to heat curing can be performed. The heating temperature for heat curing is preferably in the range of 50 to 250 ° C, particularly preferably in the range of 60 to 230 ° C. The heating time is preferably in the range of 2 to 30 minutes, particularly preferably in the range of 5 to 20 minutes.

  The epoxy resin composition of the present invention is used for general purposes such as water-based paints for building interiors, water-based paints for building exteriors and inorganic building materials, iron-based rust-preventing water-based paints, water-based paints for automobile repairs, and other industries such as automobile paints and beverage cans. Used for applications. Among these, since it is excellent in corrosion resistance and dryness to touch, it is suitably used as an iron part rust preventive water-based paint for heavy corrosion prevention of steel structures and bridges, particularly as an iron part rust preventive water-based paint for undercoating.

  In addition, when using the epoxy resin composition of the present invention as an adhesive, it is not particularly limited, and can be performed by matching the adhesive surface of the substrate after application to the substrate with a spray, brush, spatula, The bonding portion can form a strong adhesive layer by fixing the surrounding area or pressure bonding. Steel plates, concrete, mortar, wood, resin sheets, resin films are suitable as the base material, and various surface treatments such as physical treatment such as polishing, electrical treatment such as corona treatment, and chemical treatment such as chemical conversion treatment are performed as necessary. More preferably, it is applied after application.

  Further, when the epoxy resin composition of the present invention is used as a fiber sizing agent, it can be carried out without any particular limitation. For example, after applying to a fiber immediately after spinning using a roller coater and winding it as a fiber strand And a method of drying. The fiber to be used is not particularly limited. For example, inorganic fibers such as glass fiber, ceramic fiber, asbestos fiber, carbon fiber, and stainless steel fiber, natural fibers such as cotton and hemp, synthetic fibers such as polyester, polyamide, and urethane. Examples of the shape of the base material include short fibers, long fibers, yarns, mats, and sheets. The amount used as the fiber sizing agent is preferably 0.1 to 2% by mass as the resin solid content with respect to the fiber.

  Moreover, when using the epoxy resin composition of this invention as a concrete primer, it is not specifically limited, It can carry out with a roll, a spray, a brush, a spatula, or a scissors.

EXAMPLES Hereinafter, although this invention is demonstrated further in detail using an Example, this invention is not limited to the range of these Examples. In the examples, all parts, percentages, ratios and the like are based on mass unless otherwise specified. GPC measurement and IR spectrum were measured under the following conditions.
1) GPC:
-Equipment: HLC-8220 GPC manufactured by Tosoh Corporation
Column: Tosoh Corporation TSK-GEL G2000HXL + G2000HXL + G3000HXL + G4000HXL
・ Solvent: Tetrahydrofuran ・ Flow rate: 1 ml / min ・ Detector: RI
2) IR:
・ Apparatus: Fourier transform infrared spectrometer ("Nicolet 380" manufactured by Thermo Electron Co., Ltd.)

(Example 1) [Preparation of water-dispersible amine-based curing agent dispersion (1)]
<Step 1>
A glass four-necked flask equipped with a thermometer, a stirrer, a nitrogen introducing tube and a cooling tube was charged with 376 g of “Epiclon 850” (bisphenol A type epoxy resin manufactured by DIC Corporation) as an epoxy resin (A), 50 While maintaining the temperature at 0 ° C., as the alkyl (polyoxyalkylene) amine compound (B), “Jephamine M-1000” (manufactured by Texaco Chemical Co., in the general formula (B-2), R ¹ is a methyl group, p: q = 3: 19 (molar ratio), compound having a weight average molecular weight of 1000) 510 g was charged in two parts (epoxy group / amino group = 4/1 (equivalent ratio)), then heated to 100 ° C., 7 It was made to react for time and the water-dispersible epoxy resin (I-1) of epoxy equivalent 866 was obtained.

<Process 2>
A glass four-necked flask equipped with a thermometer, a stirrer, a nitrogen introducing tube and a cooling tube was charged with 136 g of metaxylenediamine (MXDA) and maintained at 80 ° C., while maintaining the water-dispersible epoxy resin (I -1) 866 g was charged in 3 parts (epoxy group / amino group = 1/2 (equivalent ratio)), then heated to 100 ° C. and reacted for 4 hours to give an amine value (mgKOH / g) of 135, The following general formula of active hydrogen equivalent (g / equivalent) 340

(In the formula, p and q represent the number of repetitions derived from the synthetic raw material.)
A water-dispersible amine-based curing agent (1) represented by FIG. 1 shows a GPC chart of a water-dispersible amine curing agent (1), and FIG. 2 shows an IR spectrum of the water-dispersible amine curing agent (1).

<Step 3>
The water-dispersible amine curing agent (1) thus obtained is dispersed in a mixed solvent of water / methoxypropanol = 1/1 (weight ratio) to obtain a curing agent dispersion (1) having a nonvolatile content of 40%. Got.

(Example 2) [Preparation of water-dispersible amine-based curing agent dispersion (2)]
<Step 1>
A glass four-necked flask equipped with a thermometer, a stirrer, a nitrogen introducing tube and a cooling tube was charged with 376 g of “Epiclon 850” (bisphenol A type epoxy resin manufactured by DIC Corporation) as an epoxy resin (A), 50 While maintaining the temperature at 0 ° C., as the alkyl (polyoxyalkylene) amine compound (B), “Jephamine M-2070” (manufactured by Texaco Chemical Co., in the general formula (B-2), R ¹ is a methyl group, p: 1041 g of a compound having q = 10: 31 (molar ratio) and a weight average molecular weight of 2,000) was charged in two parts (epoxy group / amino group = 4/1 (equivalent ratio)), and then heated to 100 ° C. For 7 hours to obtain a water-dispersible epoxy resin (I-2) having an epoxy equivalent of 1223.

<Process 2>
A glass four-necked flask equipped with a thermometer, a stirrer, a nitrogen introducing tube and a cooling tube was charged with 136 g of metaxylenediamine (MXDA) and maintained at 80 ° C., while maintaining the water-dispersible epoxy resin (I -2) 1223 g was charged in 3 parts (epoxy group / amino group = 1/2 (equivalent ratio)), then heated to 100 ° C. and reacted for 4 hours to give an amine value (mgKOH / g) of 95, A water-dispersible amine-based curing agent (2) having an active hydrogen equivalent (g / equivalent) of 517 was obtained.

<Step 3>
The water-dispersible amine curing agent (2) thus obtained is dispersed in a mixed solvent of water / methoxypropanol = 1/1 (weight ratio) to obtain a curing agent dispersion (2) having a nonvolatile content of 50%. Got.

(Reference Example 1) [Preparation of main agent-1]
<Step 1>
A glass four-necked flask equipped with a thermometer, a stirrer, a nitrogen introducing tube and a cooling tube was charged with 2000 g of methoxypolyethylene glycol having a number average molecular weight of 2000 (hydroxyl value of 28.0 mgKOH / g) and 192 g of trimellitic anhydride, and an acid. The reaction is carried out at 100 ° C. for 5 hours at an anhydride group / hydroxyl equivalent ratio of 1.0 to have two or more carboxy groups and a polyethylene glycol monoalkyl ether residue in one molecule of acid value 51 mgKOH / g. Compound (a-1) was obtained.

<Process 2>
In a glass four-necked flask equipped with a thermometer, a stirrer, a nitrogen introducing tube and a cooling tube, 1096 g of the compound (a-1) having an acid value of 51 mgKOH / g obtained in Step 1 and a bisphenol A type epoxy resin (b-1) ) (“Epiclon 850” manufactured by DIC Corporation) 376 g and 4.4 g of triphenylphosphine were charged, and the epoxy resin was added in an amount of 1.0 mol (epoxy group 2 equivalents) to 1 equivalent of carboxy group. The reaction is terminated at 0 ° C. for 8 hours, the reaction is terminated with an acid value of 0 mg KOH / g, and a water-dispersible epoxy resin (i-1) having a methoxypolyethylene glycol group in the side chain having an epoxy equivalent of 1474 [g / eq] is obtained. Obtained.

<Step 3>
148 g of the water-dispersible epoxy resin (i-1) obtained in step 2 and 1000 g of an epoxy resin (“Epiclon 1055” manufactured by DIC Corporation) are mixed, and water is added in 10 portions while stirring to obtain an epoxy resin emulsion ( Main agent-1) was obtained. The properties were a non-volatile content of 59.5% and a viscosity (B-type viscometer) of 2780 mPa · s.

(Comparative Example 1) [Preparation of water-dispersible amine-based curing agent dispersion (1 ′)]
In a glass four-necked flask equipped with a thermometer, a stirrer, a nitrogen inlet tube and a condenser tube, 109 g of metaxylenediamine (MXDA) and (polyoxyalkylene) diamine compound, “Jephamine ED-900” (Texaco Chemical Co., Ltd.) An epoxy resin (manufactured by DIC Corporation) was charged with 1080 g of a polyoxyethylene chain and a polyoxypropylene chain (both terminal diamines of a polyether consisting of 12.5: 6.0 in molar ratio) and kept at 80 ° C. "Epicron 850") 376g was charged in two parts (epoxy group / amino group = 1/2 equivalent ratio)), then heated to 100 ° C and reacted for 4 hours to give an amine value (mgKOH / g) of 133 A water-dispersible amine-based curing agent (1 ′) having an active hydrogen equivalent (g / equivalent) of 231 was obtained. This was dispersed in a mixed solvent of water / methoxypropanol = 1/1 (weight ratio) to obtain a curing agent dispersion (1 ′) having a nonvolatile content of 40%.

(Comparative Example 2) [Preparation of water-dispersible amine-based curing agent dispersion (2 ′)]
In a glass four-necked flask equipped with a thermometer, a stirrer, a nitrogen introducing tube and a cooling tube, "Jephamine ED-2003" (Texaco Chemical Co., Ltd.) was used as a metaxylenediamine (MXDA) 222g and a (polyoxyalkylene) diamine compound. 780 g of a polyoxyethylene chain and a polyoxypropylene chain (both terminal diamines of a polyether consisting of 39.0: 6.0 in molar ratio) made of epoxy resin (manufactured by DIC Corporation) "Epiclon 850") 376g was charged in two parts (epoxy group / amino group = 1/2 (equivalent ratio)), then heated to 100 ° C and reacted for 4 hours to give an amine value (mgKOH / g) 160, an active hydrogen equivalent (g / equivalent) 230 of a water-dispersible amine-based curing agent (2 ′) was obtained. This was dispersed in a mixed solvent of water / methoxypropanol = 1/1 (weight ratio) to obtain a curing agent dispersion (2 ′) having a nonvolatile content of 40%.

(Evaluation)
The epoxy resin emulsion (main agent-1) obtained in Reference Example 1 was mixed with the curing agent dispersion prepared in each Example and each Comparative Example in the proportions shown in the table below, and then mixed with a mixer ("Sinkey Corporation" ARE-310 "), each paint obtained by thoroughly mixing was degreased with a steel sheet (" SPCC-SB "compliant with JIS G3141 manufactured by Engineering Test Service Co., Ltd., xylene) and then watered with sandpaper # 240. It was applied using a bar coater so that the film thickness after drying was 50 μm.

  After application and curing at 25 ° C. for 1 week, various tests were conducted under the following conditions. The results are summarized in Table 1 below.

[Dispersion stability of water-dispersible amine curing agent]
90 g of each water-soluble amine-based curing agent dispersion was weighed into a 100 ml mayonnaise bottle, stored at room temperature (25 ° C.), and visually observed after 8 hours. For the evaluation, methoxypropanol was not used, and the dispersion was only an aqueous solvent (non-volatile content: 40%).
◯: No precipitation, no separation Δ: Separation is observed ×: Aggregates are generated.

[Surface drying]
The dryness to the touch after curing for 7 days at 23 ° C. and 50% humidity was evaluated.
○: No tack ×: With tack

〔Pencil hardness〕
According to JIS K-5600-5-4 (1999), the scratch hardness (pencil method) was used.

[Impact strength]
In accordance with JIS K-5600-5-3 (1999), a DuPont type was performed with a ½ inch striker and a load of 1000 g.
○: No crack or the like at 50 cm ×: Crack or the like is observed at 50 cm.

[Cross-cut test]
In accordance with JIS K-5600-5-6 (1999), cuts were made at intervals of 1 mm, and the state of the coating film was visually observed after peeling off after applying the tape.

0: The edge of the cut is completely smooth and there is no peeling to the eyes of any lattice.
1: Small peeling of the coating film at the intersection of cuts. The cross-cut portion is clearly not affected by more than 5%.
2: The coating film is peeled along the edge of the cut and / or at the intersection. The cross-cut part is clearly affected by more than 5% but not more than 15%.
3: The coating film is partially or completely peeled along the edge of the cut, and / or various parts of the eye are partially or completely peeled off. The cross-cut part is clearly affected by more than 15% but not more than 35%.
4: The coating film is partially or completely peeled along the edge of the cut, and / or various parts of the eye are partially or completely peeled off. The cross-cut part is clearly affected by more than 35% but not more than 65%.
5: When the degree of peeling exceeds 4 above.

[Flexibility]
In accordance with JIS K-5600-5-1 (1999), the presence or absence of cracking of the coating film and peeling from the substrate was observed when bent by a cylindrical mandrel (diameter 2 mm).
○: No cracking or peeling occurred.
X: Cracking or peeling occurred.

[Alkali resistance]
Each test plate was immersed in a 5% aqueous sodium hydroxide solution at 25 ° C. for 1 week, and the appearance was observed.
○: Good and no problem ×: Either glossy, blistering or cracking is observed in the coating film

〔water resistant〕
Each test plate was immersed in water at 25 ° C. for 1 week, and then the appearance was observed.
○: Good and no problem ×: Either glossy, blistering or cracking is observed in the coating film

[Corrosion resistance]
This was performed according to JIS K-5600-7-1 (1999). After putting the crosscut into the test piece with a cutter, placing it in the tester and conducting the test for 300 hours, the swell width of the coating film from the crosscut portion is noted. The unit is mm.

Claims (18)

Modified epoxy resin (I) obtained by reacting epoxy resin (A) having two or more epoxy groups in one molecule with alkyl (polyoxyalkylene) amine compound (B), and aromatic diamine (II) An amine-based curing agent comprising an aromatic diamine adduct of an epoxy resin having an alkyl (polyoxyalkylene) group in the side chain obtained by reacting The amine curing agent according to claim 1, wherein the aromatic diamine (II) is aralkylenediamine. The alkyl (polyoxyalkylene) amine compound (B) is represented by the general formula (B-1)

(In the formula, n is an integer of 2 to 100, a plurality of R's independently represent —CH ₂ —CHR ² — or —CHR ² —CH ₂ —, R ¹ represents an alkyl group, R ² Represents a hydrogen atom or an alkyl group, and R ³ represents a hydrogen atom or an alkyl group.)
The amine curing agent according to claim 1, which is a compound represented by the formula: The alkyl (polyoxyalkylene) amine compound (B) is represented by the general formula (B-2)

(In the formula, p and q are each independently an integer of 2 to 90, and the upper limit of the sum of p and q is 100, and R ¹ represents an alkyl group.)
The amine curing agent according to claim 3, which is a compound represented by the formula: General formula for amine curing agent

(In the formula, n is an integer of 2 to 100, a plurality of R's independently represent —CH ₂ —CHR ² — or —CHR ² —CH ₂ —, R ¹ represents an alkyl group, R ² Represents a hydrogen atom or an alkyl group, and R ³ represents a hydrogen atom or an alkyl group.)
The amine curing agent according to claim 2, which is a compound represented by the formula: General formula for amine curing agent

(In the formula, p and q are each independently an integer of 2 to 90, and the upper limit of the sum of p and q is 100, and R ¹ represents an alkyl group.)
The amine curing agent according to claim 5, which is a compound represented by the formula: Modified epoxy resin having an alkyl (polyoxyalkylene) group in the side chain by reacting an epoxy resin (A) having two or more epoxy groups in one molecule with an alkyl (polyoxyalkylene) amine compound (B) A first step of producing (I),
It comprises an aromatic diamine adduct of an epoxy resin having an alkyl (polyoxyalkylene) group in the side chain, which has a second step of reacting the modified epoxy resin (I) with an aromatic diamine (II). A method for producing an amine curing agent. The method for producing an amine curing agent according to claim 7, wherein the aromatic diamine (II) is aralkylenediamine. The alkyl (polyoxyalkylene) amine compound (B) is represented by the general formula (B-1)

(In the formula, n is an integer of 2 to 100, a plurality of R's independently represent —CH ₂ —CHR ² — or —CHR ² —CH ₂ —, R ¹ represents an alkyl group, R ² Represents a hydrogen atom or an alkyl group, and R ³ represents a hydrogen atom or an alkyl group.)
The method for producing an amine curing agent according to claim 7, wherein the compound is represented by the formula: The alkyl (polyoxyalkylene) amine compound (B) is represented by the general formula (B-2)

(In the formula, p and q are each independently an integer of 2 to 90, and the upper limit of the sum of p and q is 100, and R ¹ represents an alkyl group.)
The method for producing an amine curing agent according to claim 9, wherein the compound is represented by the formula: The method for producing an amine-based curing agent according to claim 7, wherein 2 to 5 equivalents of the aromatic diamine (II) are reacted with 1 equivalent of the modified epoxy resin (I). An epoxy resin composition comprising the epoxy resin (I) according to claim 1 and the amine curing agent according to claim 1. The epoxy resin composition according to claim 12, further comprising an epoxy resin (I ') other than the epoxy resin (I). An epoxy resin composition comprising the epoxy resin (I) according to claim 1, the amine curing agent according to claim 1, and an aqueous solvent. The epoxy resin composition according to claim 14, further comprising an epoxy resin (I ′) other than the epoxy resin (I). The epoxy resin composition according to claim 14 or 15, wherein the epoxy resin and the amine curing agent are dispersed in an aqueous solvent. The epoxy resin composition according to any one of claims 14 to 16, wherein the aqueous solvent is a mixture of water and water-soluble ketones. Hardened | cured material obtained by hardening | curing the epoxy resin composition of any one of Claims 14-17.

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