JP2012236975A - Curable epoxy resin composition for blade of wind power generator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a curable epoxy resin composition for the blade of a wind power generator having a prolonged pot life, by which a high-strength cured material is obtained.SOLUTION: The curable epoxy resin composition for the blade of the wind power generator includes (D1) an epoxy compound having in a molecule, two or more alicyclic epoxy groups which is formed by including the adjacent two carbon atoms of alicycles composed by the epoxy group, and (B) an amine curing agent, or further (C) a curing accelerator. The composition may further include an epoxy compound (D2) including an aromatic glycidyl ether type epoxy compound. Besides, the amine curing agent (B) is preferably a cycloaliphatic polyamine.

Description

  The present invention relates to a curable epoxy resin composition for wind power generator blades.

  From the viewpoint of protecting the global environment, wind power generators are attracting attention. A wind power generator generally includes a support column and a blade (blade) that is rotatably supported by the support column. The blade is rotated by wind force, and electric power is generated by the rotational force. In such a wind power generator, the blades are required to have a large size in order to efficiently convert wind power into electric power as well as strength enough to withstand wind power.

  Japanese Patent Application Laid-Open No. 2009-275536 discloses a blade of a wind turbine for wind power generators that is formed of a foamed resin molded body and whose surface is covered with a thermoplastic resin coating material. However, such blades are not strong enough and are easily damaged by strong winds.

JP 2009-275536 A

  The present inventors have studied a curable resin composition containing a bisphenol A type epoxy resin in order to obtain a high-strength wind power generator blade, but the resin composition is excellent in terms of the strength of the cured product. Since the pot life of the product was short and the molding workability was inferior, it was found that the product was not suitable as a resin composition for producing a large wind power generator blade.

Accordingly, an object of the present invention is to provide a curable epoxy resin composition for wind power generator blades, which has a long pot life and can provide a cured product having high strength.
Another object of the present invention is to provide a curable epoxy resin composition for wind power generator blades that is low in viscosity and excellent in handleability and workability, in addition to the above properties, and in addition to the above properties, a cured product with high toughness. It is providing the curable epoxy resin composition for wind power generator blades obtained.

  As a result of intensive studies to achieve the above object, the inventors of the present invention have a long pot life (high stability at room temperature) according to an epoxy resin composition containing an epoxy compound having a specific structure and an amine curing agent. In addition, the present inventors have found that a cured product having a high strength can be obtained by curing, and that it is possible to cope with an increase in the size of a wind power generator blade.

  That is, the present invention relates to (D1) an epoxy compound having two or more alicyclic epoxy groups formed in the molecule containing two adjacent carbon atoms constituting the alicyclic ring, and (B) an amine. A curable epoxy resin composition for wind power generator blades (hereinafter, referred to as “first curable epoxy resin composition for wind power generator blades”) further comprising (C) a curing accelerator. Provide).

  The first curable epoxy resin composition for wind power generator blades may further contain an epoxy compound (D2) containing an aromatic glycidyl ether type epoxy compound.

  The present invention also includes (A) an epoxy compound (A1) having two or more alicyclic rings in the molecule in which an epoxy group is bonded to a carbon atom constituting the ring by a single bond, and two or more dienes in the molecule. It contains at least one epoxy compound selected from the group consisting of a skeleton and an epoxidized polybutadiene resin (A2) having two or more epoxy groups, and (B) an amine curing agent, or (C) curing acceleration A curable epoxy resin composition for wind power generator blades containing an agent (hereinafter sometimes referred to as “second curable epoxy resin composition for wind power generator blades”) is provided.

  The second curable epoxy resin composition for wind power generator blades further comprises an epoxy compound having two or more epoxy groups in the molecule [provided that (A1) and (A2) are excluded] (D) May be included.

  The epoxy compound (D) includes an epoxy compound (D1) and an aromatic glycidyl having two or more alicyclic epoxy groups formed in the molecule, the epoxy group including two adjacent carbon atoms constituting the alicyclic ring. It may be at least one epoxy compound selected from the group consisting of ether type epoxy compounds (D2).

  In the first or second curable epoxy resin composition for wind power generator blades, the amine curing agent (B) is preferably a cyclic aliphatic polyamine such as isophoronediamine.

  According to the curable epoxy resin composition for wind power generator blades of the present invention, a cured product having a long pot life and excellent stability at room temperature and having high strength and elastic modulus can be obtained. Therefore, it can cope with a large wind power generator blade. Moreover, according to the curable epoxy resin composition for wind power generator blades of the present invention, in addition to the above properties, the viscosity is low and the handling property is excellent. Moreover, the hardened | cured material which has high toughness can be obtained. Furthermore, according to the present invention, a cured product having practically sufficient heat resistance can be obtained.

  In the curable epoxy resin composition for a first wind power generator blade of the present invention, (D1) an alicyclic epoxy group in which an epoxy group is formed containing two adjacent carbon atoms constituting an alicyclic ring Or (B) an amine curing agent, or (C) a curing accelerator. In the second curable epoxy resin composition for wind power generator blades of the present invention, (A) two or more alicyclic rings in which an epoxy group is bonded to a carbon atom constituting the ring by a single bond in the molecule. An epoxy compound (A1) having at least one epoxy compound selected from the group consisting of an epoxidized polybutadiene resin (A2) having two or more diene skeletons and two or more epoxy groups in the molecule, and (B) an amine A curing agent, or (C) a curing accelerator.

[Epoxy compound (A)]
In the second curable epoxy resin composition for wind power generator blades of the present invention, as an epoxy compound (A), an alicyclic ring in which an epoxy group is bonded to a carbon atom constituting the ring by a single bond is contained in the molecule. At least one epoxy compound selected from the group consisting of two or more epoxy compounds (A1) and an epoxidized polybutadiene resin (A2) having two or more diene skeletons and two or more epoxy groups in the molecule is used.

[Epoxy compound (A1)]
The epoxy compound (A1) has two alicyclic rings (aliphatic cyclic skeleton in which the epoxy group is directly bonded by a single bond) in which the carbon atoms of the epoxy group are bonded to the carbon atoms constituting the ring by a single bond in the molecule. An epoxy compound having the above. An epoxy compound (A1) can be used individually by 1 type or in combination of 2 or more types.

（式中、Ｒはｑ価のアルコール［Ｒ−（ＯＨ）_q］からｑ個のＯＨを除した基、ｐは１〜５０の整数、ｑは１〜１０の整数を示す。ｑ個の括弧内の基において、ｐはそれぞれ同一であっても異なっていてもよい）
で表される化合物が挙げられる。 As such a compound, for example, the following formula (1)

(In the formula, R represents a group obtained by dividing q OH from q-valent alcohol [R- (OH) _q ], p represents an integer of 1 to 50, and q represents an integer of 1 to 10. q parentheses. In the groups within the above, p may be the same or different)
The compound represented by these is mentioned.

The p is preferably 1-30. Q is preferably 2-6. As the q-valent alcohol [R- (OH) _q ], monovalent alcohols such as methanol, ethanol, 1-propanol, isopropyl alcohol, 1-butanol; ethylene glycol, 1,2-propanediol, 1,3- Propanediol, 1,4-butanediol, neopentyl glycol, 1,6-hexanediol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, dipropylene glycol, polypropylene glycol, cyclohexanedimethanol, hydrogenated bisphenol A, Divalent alcohols such as hydrogenated bisphenol F and hydrogenated bisphenol S; glycerin, diglycerin, polyglycerin, erythritol, trimethylolethane, trimethylolpropane, pentaerythritol Lithol, dipentaerythritol, and a trihydric or higher alcohols such as sorbitol. The alcohol may be polyether polyol, polyester polyol, polycarbonate polyol, polyolefin polyol, or the like. The alcohol is preferably an aliphatic alcohol having 1 to 10 carbon atoms, particularly an aliphatic polyvalent having 2 to 10 carbon atoms such as trimethylolpropane [= 2,2-bis (hydroxymethyl) -1-butanol]. Alcohol is preferred.

The compound represented by the formula (1) is obtained, for example, by polycyclic ring-opening polymerization of 4-vinylcyclohexene-1-oxide using the q-valent alcohol [R— (OH) _q ] as an initiator. It can be produced by epoxidizing an ether resin, that is, a vinyl group side chain of polycyclohexene oxide having a vinyl group side chain with an oxidizing agent such as peracid (peracetic acid or the like). In addition, the compound represented by Formula (1) may contain in the molecule | numerator the group derived from the unreacted vinyl group or the raw material used for reaction.

  A commercial item can be used as a compound represented by Formula (1). As a commercial item, there exists a brand name "EHPE3150" (made by Daicel Chemical Industries Ltd.) etc., for example.

[Epoxidized polybutadiene resin (A2)]
The epoxidized polybutadiene resin (A2) is an epoxidized polybutadiene resin having two or more diene skeletons and two or more epoxy groups in the molecule. The epoxidized polybutadiene resin (A2) can be used alone or in combination of two or more.

  The terminal group of the epoxidized polybutadiene resin may be a hydrogen atom, a hydroxyl group, a cyano group, or the like. As the terminal group, a hydrogen atom and a hydroxyl group are particularly preferable.

  The epoxidized polybutadiene resin can be obtained by reacting an epoxidizing agent with the polybutadiene resin. In the polybutadiene resin as a raw material, the steric structure of the double bond site may be any of cis-1,4, trans-1,4, trans-1,2, and cis-1,2. Moreover, those ratios may be arbitrary. Examples of the epoxidizing agent include organic peracids such as peracetic acid, performic acid, perbenzoic acid, trifluoroperacetic acid and perpropionic acid, and organic hydroperoxides such as hydrogen peroxide, t-butyl hydroperoxide and cumene hydroperoxide. Oxides can be used. As the organic peracid, one that does not substantially contain water (for example, 0.8% by weight or less in terms of water content) is preferable in order to increase the oxirane oxygen concentration of the target product. Among the epoxidizing agents, peracetic acid is particularly preferable because it can be obtained industrially at low cost and has high stability.

  The number average molecular weight of the epoxidized polydiene resin is, for example, 500 to 50000, preferably 2500 to 30000, and more preferably 3500 to 20000. The oxirane oxygen concentration of the epoxidized polydiene resin is, for example, 3 to 15%, preferably 5 to 12%. The number of epoxy groups in one molecule is preferably 5 or more (for example, 5 to 200), more preferably 10 or more, and still more preferably 20 or more.

  A commercially available product can be used as the epoxidized polydiene resin. As a commercial item, there exists a brand name "EPL PB3600" (made by Daicel Chemical Industries Ltd.) etc., for example.

[Epoxy compound (D)]
In addition to the epoxy compound (A), the second curable epoxy resin composition for wind power generator blades of the present invention further includes an epoxy compound having two or more epoxy groups in the molecule, if necessary. However, (except for (A1) and (A2)) (D) may be included. An epoxy compound (D) can be used individually by 1 type or in combination of 2 or more types.

  The epoxy compound (D) is not particularly limited. For example, (D1) an alicyclic epoxy group formed by including two adjacent carbon atoms that constitute an alicyclic ring (cycloaliphatic skeleton). Two or more epoxy compounds, (D2) aromatic glycidyl ether type epoxy compounds, (D3) aliphatic polyhydric alcohol polyglycidyl ethers, (D4) other epoxy compounds, and the like can be used.

  Examples of the epoxy compound (D1) having two or more alicyclic epoxy groups formed by including two adjacent carbon atoms constituting the alicyclic epoxy group include compounds represented by the following formula (2).

  The alicyclic epoxy compound represented by the above formula (2) is produced by oxidizing a corresponding alicyclic olefin compound with an aliphatic percarboxylic acid or the like, and uses a substantially anhydrous aliphatic percarboxylic acid. It is preferable in that it has a high epoxidation rate.

  In the above formula (2), Y represents a single bond or a linking group. Examples of the linking group include a divalent hydrocarbon group, a carbonyl group (—CO—), an ether bond (—O—), an ester bond (—COO—), an amide bond (—CONH—), and a carbonate bond (— OCOO-) and a group in which a plurality of these are linked. Examples of the divalent hydrocarbon group include a linear or branched alkylene group having 1 to 18 carbon atoms (particularly 1 to 6) and a divalent alicyclic hydrocarbon group (particularly a divalent cycloalkylene group). And the like are preferably exemplified. Examples of the linear or branched alkylene group include methylene, methylmethylene, dimethylmethylene, ethylene, propylene, and trimethylene groups. Examples of the divalent alicyclic hydrocarbon group include 1,2-cyclopentylene, 1,3-cyclopentylene, cyclopentylidene, 1,2-cyclohexylene, 1,3-cyclohexylene, Examples include 1,4-cyclohexylene and cyclohexylidene groups. As Y, a linking group containing an ester bond and a divalent hydrocarbon group, and a single bond are particularly preferable.

  Specific examples of the alicyclic epoxy compound represented by the formula (2) include the following compounds.

  In said formula, n is an integer of 1-30.

  As the aromatic glycidyl ether type epoxy compound (D2), for example, bisphenol A type epoxy resin (bisphenol A diglycidyl ether; condensation product of bisphenol A and epichlorohydrin having glycidyl ether groups at both ends) Bisphenol F type epoxy resin (bisphenol F diglycidyl ether; condensation product of bisphenol F and epichlorohydrin having glycidyl ether groups at both ends), bisphenol S type epoxy resin (bisphenol S diglycidyl ether; both In addition to bisphenol diepoxy resins such as condensation products of bisphenol S and epichlorohydrin having a glycidyl ether group at the terminal, etc., 4,4'-dihydroxybiphenyl diglycidyl ether, 4,4'-di Droxy-3,3 ′, 5,5′-tetramethylbiphenyldiglycidyl ether, 1,6-dihydroxynaphthalenediglycidyl ether, glycidyl ether of dicyclopentadiene and phenol adduct, 9,9′-bis (4- Hydroxyphenyl) fluorene diglycidyl ether and the like.

  The aliphatic polyhydric alcohol polyglycidyl ether (D3) is not particularly limited, and a wide range of aliphatic glycidyl ether type epoxy compounds can be used. Examples of the “aliphatic polyhydric alcohol” in the aliphatic polyhydric alcohol polyglycidyl ether include, for example, ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,4- Divalent alcohols such as butanediol, 1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, dipropylene glycol, polypropylene glycol; glycerin, di Examples include trivalent or higher alcohols such as glycerin, polyglycerin, erythritol, trimethylolethane, trimethylolpropane, pentaerythritol, and dipentaerythritol.

  Representative examples of the aliphatic polyhydric alcohol polyglycidyl ether include 1,6-hexanediol diglycidyl ether, 1,4-butanediol diglycidyl ether, trimethylolpropane polyglycidyl ether, diethylene glycol diglycidyl ether, neopentyl glycol Examples include diglycidyl ether, propylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, and polyethylene glycol diglycidyl ether.

  Other epoxy compounds (D4) include, for example, compounds represented by the following formula, and polyglycidylamine type such as N, N, N ′, N′-tetraglycidyl-4,4′-methylene-bisbenzamine. An epoxy resin etc. are mentioned. In the following formulae, a, b, c, d, e, and f are each an integer of 0 to 30.

  As the epoxy compound (D), among the above, (D1) an epoxy compound having two or more alicyclic epoxy groups formed by including two adjacent carbon atoms that constitute the alicyclic ring, (D2) Aromatic glycidyl ether type epoxy compounds are particularly preferred.

  In addition, the curable epoxy resin composition for wind power generator blades of the present invention may contain an epoxy compound other than the above.

  In the second curable epoxy resin composition for wind power generator blades of the present invention, the total amount of the epoxy compound (A) is usually 3 wt% with respect to the total amount of the epoxy compound in the curable epoxy resin composition. % Or more, more preferably 5% by weight or more, and may be 7% by weight or more. Further, in the second curable epoxy resin composition for wind power generator blades of the present invention, the total amount of the epoxy compound (A) and the epoxy compound (D) is the amount of the total epoxy compound in the curable epoxy resin composition. Is preferably 70% by weight or more, more preferably 85% by weight or more, and particularly preferably 95% by weight or more.

  When the epoxy compound (A1) is used as the epoxy compound (A) in the second curable epoxy resin composition for wind power generator blades of the present invention, an epoxy resin composition using a conventional aromatic glycidyl ether type epoxy resin Compared with the product, the pot life of the resin composition is remarkably increased, and the handleability and molding workability are greatly improved. Moreover, the strength and elastic modulus of the cured product are also excellent. When using the said epoxy compound (A1) as an epoxy compound (A), the total amount of an epoxy compound (A1) is 5 weight% or more with respect to the total amount of the epoxy compound in this thermosetting epoxy resin composition ( 5 to 100% by weight), more preferably 10% by weight or more (10 to 100% by weight), and further preferably 30% by weight or more (30 to 100% by weight). In addition, when using the said epoxy compound (A1) as an epoxy compound (A), you may use the said epoxy compound (D1) and / or aromatic glycidyl ether type epoxy compound (D2) with an epoxy compound (A1). In this case, the ratio (weight ratio) between the epoxy compound (A1) and the epoxy compound (D1) is the former / the latter = 1/99 to 99/1, preferably 10/90 to 90/10, more preferably 30/70. ~ 70/30. In this case, the total amount of (A1), (D1), and (D2) is, for example, 70% by weight or more (70 to 100% by weight) with respect to the total amount of the epoxy compound in the curable epoxy resin composition. More preferably, it is 85% by weight or more (85-100% by weight), and more preferably 95% by weight or more (95-100% by weight).

  When the epoxidized polybutadiene resin (A2) is used as the epoxy compound (A) in the second curable epoxy resin composition for wind power generator blades of the present invention, an epoxy using a conventional aromatic glycidyl ether type epoxy resin Compared with the resin composition, the pot life of the resin composition becomes longer, handling properties and molding workability are improved, and in particular, the toughness of the cured product is greatly improved. Moreover, the strength and elastic modulus of the cured product are also excellent. When using the said epoxidized polybutadiene resin (A2) as an epoxy compound (A), the total amount of an epoxy compound (A2) is 3 weight% with respect to the quantity of all the epoxy compounds in this curable epoxy resin composition, for example. Above (3 to 80% by weight), more preferably 5% by weight or more (5 to 50% by weight), still more preferably 7% by weight or more (7 to 30% by weight). In addition, when using the said epoxidized polybutadiene resin (A2) as an epoxy compound (A), the said epoxy compound (D1) and / or aromatic glycidyl ether type epoxy compound (D2) are used with an epoxidized polybutadiene resin (A2). May be. In this case, the ratio (weight ratio) between the epoxy compound (A1) and the aromatic glycidyl ether type epoxy compound (D2) is the former / the latter = 1/99 to 99/1, preferably 3/97 to 70/30, Preferably it is 5/95-50/50. In this case, the total amount of (A2), (D1), and (D2) is, for example, 70% by weight or more (70 to 100% by weight) with respect to the total amount of the epoxy compound in the curable epoxy resin composition. More preferably, it is 85% by weight or more (85-100% by weight), and more preferably 95% by weight or more (95-100% by weight).

  As described above, the first curable epoxy resin composition for wind power generator blades of the present invention is formed by including, as an epoxy compound, the two adjacent carbon atoms in which the (D1) epoxy group constitutes an alicyclic ring. An epoxy compound having two or more alicyclic epoxy groups in the molecule is included. Such a curable epoxy resin composition significantly increases the pot life of the resin composition and greatly reduces the viscosity as compared with an epoxy resin composition using a conventional aromatic glycidyl ether type epoxy resin. As a result, the handleability and molding workability are remarkably improved, and the elastic modulus of the cured product is greatly improved.

  The curable epoxy resin composition for a first wind power generator blade of the present invention may further contain the aromatic glycidyl ether type epoxy compound (D2). In the curable epoxy resin composition containing the epoxy compounds (D1) and (D2) as the epoxy compound, in addition to the above properties, the bending strength and toughness of the cured product are further improved.

  In the curable epoxy resin composition for a first wind power generator blade of the present invention, the total amount of the epoxy compounds (D1) and (D2) is based on the total amount of the epoxy compounds in the curable epoxy resin composition. Usually, it is 50% by weight or more, more preferably 70% by weight or more, and may be 90% by weight or more.

  In the first curable epoxy resin composition for wind power generator blades of the present invention, the ratio (weight ratio) of the epoxy compound (D2) to the epoxy compound (D1) is usually the former / the latter = 0/100 to 99 /. 1 (for example, 1/99 to 99/1), preferably the former / the latter = 0/100 to 95/5 (for example, 30/70 to 95/5), more preferably the former / the latter = 0/100 to 90 / 10 (for example, 50/50 to 90/10). In particular, when it is desired to increase the pot life of the resin composition, the ratio (weight ratio) of the epoxy compound (D2) to the epoxy compound (D1) is preferably the former / the latter = 0/100 to 10/90, more preferably. The former / the latter = 0/100 to 50/50, more preferably the former / the latter = 0/100 to 70/30.

  The epoxy compound used in the curable epoxy resin composition for wind power generator blades of the present invention (the first curable epoxy resin composition for wind power generator blades and the second curable epoxy resin composition for wind power generator blades) is: From the viewpoint of improving workability at the time of blending and manufacturing a fiber-reinforced composite material, it is preferably liquid at any temperature of 0 to 50 ° C. [for example, room temperature (25 ° C.)]. However, even if it is a solid epoxy compound as a simple substance, it can be used as long as the viscosity (25 ° C.) of the curable epoxy resin composition after blending each component is, for example, 150,000 mPa · s or less. . The viscosity (25 ° C.) of the epoxy compound (a mixture of all the epoxy compounds to be used) is, for example, 150,000 mPa · s or less, preferably 100,000 mPa · s or less, more preferably 50000 mPa · s or less, further preferably 10,000 Pa · s or less, Particularly preferably, it is 6000 mPa · s or less. If this viscosity is too large, the molding workability and the like tend to decrease. In particular, when an epoxy compound (D1) is used, the viscosity of the mixture of all epoxy compounds can be reduced.

[Amine curing agent (B)]
The amine curing agent (B) can be arbitrarily selected from those generally known as epoxy resin curing agents. A polyamine can be suitably used as the amine curing agent (B). The polyamine is preferably liquid at room temperature. When a polyamine that is solid at room temperature is used, it is preferably dissolved in a liquid polyamine at room temperature and used as a liquid mixture at room temperature. An amine hardening | curing agent (B) can be used individually by 1 type or in combination of 2 or more types.

  Specific examples of polyamines include, for example, chain aliphatics such as diethylenetriamine, triethylenetetramine, tetraethylenepentamine, hexamethylenediamine, 1,3-pentanediamine, 2-methylpentamethylenediamine, dipropylenediamine, and diethylaminopropylamine. Polyamine: N-aminoethylpiperazine, mensendiamine, isophoronediamine, 4,4'-methylenebiscyclohexyl, 4,4'-methylenebis (2-methylcyclohexylamine), bis (aminomethyl) norbornane, 1,2-cyclohexane Cyclic aliphatic polyamines (alicyclic polyamines) such as diamine and 1,3-bisaminomethylcyclohexane; polyether polyamines; m-xylylenediamine, 4,4′-methylenedianiline, 4,4 -Methylenebis (2-methylaniline), 4,4'-methylenebis (2-ethylaniline), 4,4'-methylenebis (2-isopropylaniline), 4,4'-methylenebis (2-chloroaniline), 4, 4'-methylenebis (2,6-dimethylaniline), 4,4'-methylenebis (2,6-diethylaniline), 4,4'-methylenebis (2-isopropyl-6-methylaniline), 4,4'- Methylenebis (2-ethyl-6-methylaniline), 4,4'-methylenebis (2-bromo6-ethylaniline), 4,4'-methylenebis (N-methylaniline), 4,4'-methylenebis (N- Ethylaniline), 4,4'-methylenebis (N-sec-butylaniline), 4,4'-diaminodiphenylsulfone, 3,3'-diamy Diphenylsulfone, 4,4'-cyclohexylidenedianiline, 4,4 '-(9-fluorenylidene) dianiline, 4,4'-(9-fluorenylidene) bis (N-methylaniline), 4,4'-diaminobenz Anilide, 4,4'-oxydianiline, 2,4-bis (4-aminophenylmethyl) aniline, 4-methyl-m-phenylenediamine, 2-methyl-m-phenylenediamine, N, N'-di- sec-butyl-p-phenylenediamine, 2-chloro-p-phenylenediamine, 2,4,6-trimethyl-m-phenylenediamine, diethyltoluenediamine (2,4-diethyl-6-methyl-m-phenylenediamine and 4,6-diethyl-2-methyl-m-phenylenediamine, etc.), bis (methylthio) toluene di Amines [mixtures of 6-methyl-2,4-bis (methylthio) -m-phenylenediamine and 2-methyl-4,6-bis (methylthio) -m-phenylenediamine, etc.], 4,6-dimethyl-m- Phenylenediamine, trimethylenebis (4-aminobenzoate), 1,3-bis (4-aminophenoxy) benzene, 1,3-bis (3-aminophenoxy) benzene, α, α-bis (4-aminofailure) And aromatic polyamines such as -p-diisopropylbenzene and 1,3-bis (m-aminophenyl) benzene.

  Among these, it is preferable to use an aromatic polyamine as the polyamine from the viewpoint of obtaining a cured product having excellent heat resistance and high elastic modulus. From the viewpoint of obtaining a cured product having a low viscosity, excellent handleability and molding workability, and having a high toughness and a high elastic modulus, it is preferable to use a cyclic aliphatic polyamine as the polyamine. Particularly preferred polyamines are cycloaliphatic polyamines such as, for example, isophorone diamine.

  Although the compounding quantity of an amine hardening | curing agent (B) changes also with the kind, generally epoxy compound (A) [when using an epoxy compound (D) with an epoxy compound (A), those total amounts] 100 weight part (or 1 to 100 parts by weight, preferably 5 to 80 parts by weight, and more preferably 10 to 70 parts by weight with respect to 100 parts by weight of the total amount of epoxy compounds in the composition. In particular, the amine curing agent (B) should be used in such a ratio that the amine equivalent is 0.5 to 1.5 per equivalent of epoxy group in the epoxy compound in the thermosetting epoxy resin composition of the present invention. Is preferred.

[Curing accelerator (C)]
The curing accelerator (C) is not particularly limited as long as it is a curing accelerator generally used for accelerating the curing rate when an epoxy compound is cured using an amine curing agent. For example, a tertiary amine , Tertiary amine salts, imidazoles, organophosphorus compounds, quaternary ammonium salts, quaternary phosphonium salts, quaternary arsonium salts, tertiary sulfonium salts, tertiary selenonium salts, secondary iodonium salts Further, onium salts such as diazonium salts, strong acid esters, Lewis acid and base complexes, organometallic salts, and the like can be used. A hardening accelerator (C) can be used individually by 1 type or in combination of 2 or more types. Note that strong acid onium salts, strong acid esters, Lewis acid-base complexes, and the like are also referred to as latent acid catalysts.

  Examples of the tertiary amine include lauryl dimethylamine, N, N-dimethylcyclohexylamine, N, N-dimethylbenzylamine, N, N-dimethylaniline, (N, N-dimethylaminomethyl) phenol, 2,4. , 6-Tris (N, N-dimethylaminomethyl) phenol, 1,8-diazabicyclo [5.4.0] undecene-7 (DBU), 1,5-diazabicyclo [4.3.0] nonene-5 ( DBN).

  Examples of the tertiary amine salt include carboxylates, sulfonates, and inorganic acid salts of the tertiary amine. Examples of the carboxylate include salts of carboxylic acids having 1 to 30 carbon atoms (particularly 1 to 10 carbon atoms) such as octylates (particularly salts of fatty acids). Examples of the sulfonate include p-toluenesulfonate, benzenesulfonate, methanesulfonate, and ethanesulfonate. Typical examples of the tertiary amine salt include salts of 1,8-diazabicyclo [5.4.0] undecene-7 (DBU) (for example, p-toluenesulfonate, octylate). .

  Examples of imidazoles include 2-methylimidazole, 2-ethylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, and 1-benzyl. -2-methylimidazole and the like.

  Examples of the organic phosphorus compound include triphenylphosphine and triphenyl phosphite.

  Examples of the quaternary ammonium salt include tetraethylammonium bromide and tetrabutylammonium bromide. Moreover, as a quaternary ammonium salt, perchlorate ion, tetrafluoroborate ion, sulfonate ion (p-toluenesulfonate ion, benzenesulfonate ion, 4-chlorobenzenesulfonate ion, dodecylbenzenesulfonate ion, methanesulfonate as counter ions. Quaternary ammonium salts having ions, trifluoromethanesulfonate ions, etc.), hexafluorophosphate ions, hexafluoroantimonate ions, tetrakis (pentafluorophenyl) borate ions, and the like can also be used.

  Examples of the quaternary phosphonium salt include tetrabutyl phosphonium decanoate, tetrabutyl phosphonium laurate, tetrabutyl phosphonium myristate, tetrabutyl phosphonium palmitate, tetrabutyl phosphonium cation and bicyclo [2.2.1. ] Salts of heptane-2,3-dicarboxylic acid and / or methylbicyclo [2.2.1] heptane-2,3-dicarboxylic acid anion, tetrabutylphosphonium cation and 1,2,4,5-cyclohexanetetra Examples thereof include salts with anions of carboxylic acids. Moreover, as a quaternary phosphonium salt, perchlorate ion, tetrafluoroborate ion, sulfonate ion (p-toluenesulfonate ion, benzenesulfonate ion, 4-chlorobenzenesulfonate ion, dodecylbenzenesulfonate ion, methanesulfonate as counter ions. Quaternary phosphonium salts having ions, trifluoromethanesulfonate ions, etc.), hexafluorophosphate ions, hexafluoroantimonate ions, tetrakis (pentafluorophenyl) borate ions, and the like.

  As quaternary arsonium salt, tertiary sulfonium salt, tertiary selenonium salt, secondary iodonium salt, diazonium salt, perchlorate ion, tetrafluoroborate ion, sulfonate ion (p- Toluenesulfonate ion, benzenesulfonate ion, 4-chlorobenzenesulfonate ion, dodecylbenzenesulfonate ion, methanesulfonate ion, trifluoromethanesulfonate ion, etc.), hexafluorophosphate ion, hexafluoroantimonate ion, tetrakis (pentafluorophenyl) borate ion, etc. A quaternary arsonium salt, tertiary sulfonium salt, tertiary selenonium salt, secondary iodonium salt or diazonium salt having

  Examples of strong acid esters include sulfuric acid esters, sulfonic acid esters, phosphoric acid esters, phosphinic acid esters, and phosphonic acid esters.

  Examples of the Lewis acid and base complex include those that dissociate at a high temperature to produce a Lewis acid. As the Lewis acid, boron halides such as boron trifluoride and boron trichloride, phosphorus pentafluoride, antimony pentafluoride and the like are preferable. As the base, an organic amine is preferable. Representative examples of Lewis acid and base complexes include boron trifluoride / aniline complex, boron trifluoride / p-chloroaniline complex, boron trifluoride / ethylamine complex, boron trifluoride / isopropylamine complex, three Boron fluoride / benzylamine complex, boron trifluoride / dimethylamine complex, boron trifluoride / diethylamine complex, boron trifluoride / dibutylamine complex, boron trifluoride / piperidine complex, boron trifluoride / dibenzylamine Complex, boron trichloride / dimethyloctylamine complex, and the like.

  Examples of the organic metal salt include tin octylate, zinc octylate, dibutyltin dilaurate, and aluminum acetylacetone complex.

  Among these curing accelerators, a fourth ion having perchlorate ions, tetrafluoroborate ions, sulfonate ions, hexafluorophosphate ions, hexafluoroantimonate ions, tetrakis (pentafluorophenyl) borate ions, etc. as counter ions. Potential of quaternary ammonium salts, quaternary phosphonium salts, quaternary arsonium salts, tertiary sulfonium salts, tertiary selenonium salts, secondary iodonium salts or diazonium salts; strong acid esters; Lewis acid and base complexes Acid catalysts are preferred, and in particular, Lewis acid and base complexes such as boron trifluoride / piperidine complex and boron trichloride / dimethyloctylamine complex are preferred.

  Although the compounding quantity of a hardening accelerator (C) changes with kinds of amine hardening | curing agent (B), it is 0.1-60 weight part normally with respect to 100 weight part of amine hardening | curing agents (B), Preferably it is 1 -50 parts by weight, more preferably 5-40 parts by weight. Moreover, the compounding quantity of a hardening accelerator (C) is epoxy compound (A) [when using an epoxy compound (D) with an epoxy compound (A), those total amounts] 100 weight part (or an epoxy compound in a composition) For example, 0.2 to 20 parts by weight, preferably 1 to 16 parts by weight, and more preferably 2 to 10 parts by weight. In addition, in order to improve the toughness of hardened | cured material, the compounding quantity of a hardening accelerator (C) is epoxy compound (A) [The total amount when using an epoxy compound (D) with an epoxy compound (A)] 100 For example, 0 to 5 parts by weight, preferably 0 to 3 parts by weight, and more preferably 0 to 2 parts by weight with respect to parts by weight (or 100 parts by weight of the total amount of epoxy compounds in the composition). Is desirable.

 In addition to the above components, the curable epoxy resin composition for wind power generator blades of the present invention may contain various additives within a range that does not adversely affect the physical properties of the cured product. Examples of such additives include surfactants, internal mold release agents, colorants, flame retardants, antifoaming agents, silane coupling agents, fillers, antioxidants, ultraviolet absorbers, and the like. . The blending amount of these various additives is preferably 10% or less (particularly 5% or less) based on the weight of the curable epoxy resin composition. Therefore, in the curable epoxy resin composition for wind power generator blades of the present invention, the total amount of all epoxy compounds, amine curing agent and curing accelerator is preferably 90% by weight or more, and 95% by weight or more. It is particularly preferred.

  The curing temperature of the curable epoxy resin composition for wind power generator blades of the present invention varies depending on the type of epoxy compound, but is, for example, 20 to 250 ° C, preferably 40 to 220 ° C. Curing may be performed in multiple stages by changing the curing temperature. For example, curing is carried out under conditions of 20 to 140 ° C. (preferably 40 to 120 ° C.) and 0.1 to 8 hours (preferably 0.3 to 4 hours), and then a temperature exceeding 140 ° C. And a step of curing under conditions of 250 ° C. (preferably 150 to 220 ° C.) and 0.1 to 8 hours (preferably 0.3 to 4 hours).

  Glass transition temperature of a cured product (for example, a cured product obtained by curing at 110 ° C. for 2 hours and 180 ° C. for 2 hours) of the curable epoxy resin composition for wind power generator blades of the present invention [thermomechanical measurement device ( The measured value according to TMA) is, for example, 50 ° C. or higher, preferably 60 ° C. or higher. Further, the glass transition temperature [thermomechanical measurement] of a cured product of the curable epoxy resin composition for wind power generator blades of the present invention (for example, a cured product obtained by curing at 80 ° C. for 2 hours and 200 ° C. for 2 hours). The measured value by the apparatus (TMA)] is, for example, 90 ° C. or higher, preferably 100 ° C. or higher.

  The bending strength of a cured product of the curable epoxy resin composition for wind power generator blades of the present invention (for example, a cured product obtained by curing at 110 ° C. for 2 hours and 180 ° C. for 2 hours) is, for example, 70 MPa. Above, preferably 80 MPa or more. The bending strength of the cured product of the curable epoxy resin composition for wind power generator blades of the present invention (for example, a cured product obtained by curing at 80 ° C. for 2 hours and 200 ° C. for 2 hours) is, for example, 90 MPa. Above, preferably 100 MPa or more. Further, a cured product of the curable epoxy resin composition for wind power generator blades of the present invention (for example, a cured product obtained by curing at 110 ° C. for 2 hours and 180 ° C. for 2 hours, or 80 ° C. for 2 hours, and The bending elastic modulus of the cured product obtained by curing at 200 ° C. for 2 hours is, for example, 1600 MPa or more, preferably 2000 MPa or more, and more preferably 2500 MPa or more. In particular, when the epoxy compound (A1) is used as the epoxy compound (A), or when the epoxy compound (D1) is used, the bending elastic modulus may be set to 2800 MPa or more (further 3500 MPa or more). Is possible.

  Further, a cured product of the curable epoxy resin composition for wind power generator blades of the present invention (for example, a cured product obtained by curing at 110 ° C. for 2 hours and 180 ° C. for 2 hours, or 80 ° C. for 2 hours, and Cured product obtained by curing at 200 ° C. for 2 hours), in particular, a cured product obtained by using epoxidized polybutadiene resin (A2) as epoxy compound (A), and epoxy compound (D1) and epoxy compound (D2) The cured product obtained by using exhibits a very high toughness, and does not break in the measurement of the bending elastic modulus up to a displacement of 21 mm.

  The curable epoxy resin composition for wind power generator blades of the present invention is used for producing wind power generator blades. The wind power generator blade is preferably formed of a fiber reinforced composite material composed of reinforcing fibers and a matrix resin from the viewpoint of strength and the like. The curable epoxy resin composition for wind power generator blades of the present invention is useful as a raw material (precursor before curing) of a matrix resin of a fiber reinforced composite material. The thermal characteristics and mechanical characteristics of the matrix resin (cured product of the curable epoxy resin composition) are reflected in the physical properties of the fiber-reinforced composite material. That is, if the glass transition temperature of the matrix resin is high, the heat resistance of the fiber reinforced composite material is improved. Further, if the bending strength of the matrix resin is high, the bending strength of the fiber reinforced composite material is also high. If the elastic modulus of the matrix resin is high, the compressive strength and tensile strength of the fiber reinforced composite material are improved. Furthermore, the higher the toughness of the matrix resin, the greater the toughness of the fiber reinforced composite material.

  As a method for producing a fiber reinforced composite material, any of known methods such as a hand lay-up method, a prepreg method, an RTM method, a pultrusion method, a filament winding method, and a spray-up method can be preferably applied. The RTM method, which is one of the preferred production methods, is a method in which a liquid thermosetting resin is injected into a reinforcing fiber base placed in a mold and cured to obtain a fiber-reinforced composite material. As the reinforcing fiber base material, a woven fabric made of reinforcing fibers, knit, mat, braid or the like may be used as it is, and these base materials are laminated and shaped, and the form is fixed by means such as a binder or a stitch. A preform may be used.

  Examples of the reinforcing fiber include carbon fiber, glass fiber, aramid fiber, and boron fiber. Among these, carbon fiber and glass fiber are particularly preferable. A fiber can be used individually by 1 type or in combination of 2 or more types. As the carbon fiber, for example, polyacrylonitrile (PAN) -based carbon fiber, pitch-based carbon fiber, vapor-grown carbon fiber, or the like can be used. As a glass fiber, the glass fiber normally used for resin reinforcement | strengthening can be used.

  The mold may be a closed mold made of a rigid body, or a method using a rigid single-sided mold and a flexible film (bag) is also possible. In the latter case, the reinforcing fiber base is placed between the rigid single-sided mold and the flexible film. As the rigid mold material, for example, various existing ones such as metal (iron, steel, aluminum, etc.), FRP, wood, plaster, and the like are used. As the flexible film, a film of nylon, fluorine resin, silicone resin or the like is used. When a rigid closed mold is used, it is usually performed by pressurizing and clamping and injecting the liquid epoxy resin composition under pressure. At this time, it is also possible to provide a suction port separately from the injection port and connect it to a vacuum pump for suction. It is also possible to inject the liquid epoxy resin only at atmospheric pressure without suction and using a special pressurizing means.

  When a rigid single-sided mold and a flexible film are used, suction and injection by atmospheric pressure are usually used. In order to achieve good impregnation by injection at atmospheric pressure, it is effective to use a resin diffusion medium as shown in US Pat. No. 4,902,215. In addition to the reinforcing fiber substrate, a foam core, a honeycomb core, a metal part, and the like can be installed in the mold, and a composite material integrated with these can be obtained. In particular, a sandwich structure obtained by placing and molding carbon fiber substrates on both sides of a foam core is lightweight and has a large bending rigidity, and thus is useful as an outer plate material for automobiles, aircrafts and the like. Furthermore, prior to installation of the reinforcing fiber base, it is also preferable to apply a gel coat described later on the rigid surface.

  After the resin injection is completed, heat curing is performed using an appropriate heating means, and demolding is performed. It is also possible to perform post-curing at a higher temperature after demolding.

  In addition to the RTM method, the fiber-reinforced composite material can be manufactured by a known fiber-reinforced composite material manufacturing method using a liquid epoxy resin composition such as a filament winding method or a pultrusion method as described above.

  By using the curable epoxy resin composition for wind power generator blades of the present invention, the fiber reinforced composite material for wind power generator blades, which is lightweight, high strength, high rigidity, high toughness and excellent in heat resistance, is industrially efficient. It can be manufactured well at low cost.

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

  The liquid thermosetting epoxy resin compositions obtained in the examples and comparative examples were evaluated as follows.

[Pot life]
The pot life was evaluated by measuring the gel time at 50 ° C. using a “gel time tester” manufactured by Yasuda Seiki Seisakusho.

[Heat resistance test]
A test piece (length 10 mm, width 5 mm, thickness 5 mm) obtained by thermosetting the thermosetting epoxy resin composition obtained in Examples and Comparative Examples was measured using a thermomechanical measurement apparatus (TMA) [Seiko Instruments ( The glass transition temperature (Tg, ° C.) was measured as a heat resistance index.

[Bending strength test (flexural modulus, bending strength)]
A test piece for bending strength test was prepared by processing a cured product obtained by thermosetting into a size of 5 mm × 10 mm × 80 mm. The bending strength test was performed at a bending speed of 1 mm / min according to JIS K6911. The upper limit of deflection was 21 mm.

Example 1
As the epoxy compound (A1), 1,2-epoxy-4- (2-oxiranyl) cyclohexane adduct of 2,2-bis (hydroxymethyl) -1-butanol [manufactured by Daicel Chemical Industries, Ltd., trade name “EHPE3150 ] 50 parts by weight, as epoxy compound (D1), 3,4-epoxycyclohexylmethyl (3,4-epoxy) cyclohexanecarboxylate [manufactured by Daicel Chemical Industries, Ltd., trade name “Celoxide 2021P”], 50 parts by weight, As the amine curing agent (B), isophoronediamine [Evonik Degussa Japan Co., Ltd., trade name “Vestamine IPD”] 28.2 parts by weight, as the curing accelerator (C), boron trifluoride piperidine [Stella Chemifa Corporation )] 0.5 parts by weight was used.
These were blended using “Awatori Netaro” manufactured by Shinky Co., Ltd. by mixing with stirring at room temperature for 20 minutes to obtain a liquid thermosetting epoxy resin composition.
The resulting liquid thermosetting epoxy resin composition had a gel time at 50 ° C. of 180 minutes or more. In addition, as a result of thermosetting under conditions of 110 ° C. for 2 hours + 180 ° C. for 2 hours and measuring respective physical properties, the obtained resin cured product has a glass transition temperature of 113 ° C., a flexural modulus of 3835 MPa, a bending strength. Was 90 MPa, and had excellent heat resistance and bending properties.

Example 2
As epoxidized polybutadiene resin (A2), epoxidized polybutadiene [manufactured by Daicel Chemical Industries, Ltd., trade name “EPL PB3600”] 10 parts by weight, as aromatic glycidyl ether type epoxy compound (D2), bisphenol A type epoxy resin [ 90 parts by weight manufactured by Nippon Steel Chemical Co., Ltd., trade name “Epototo YD128”, isophoronediamine [Evonik Degussa Japan Co., Ltd., trade name “Vestamine IPD”] 22.9 weights as amine curing agent (B) Parts were used.
These were blended using “Awatori Netaro” manufactured by Shinky Co., Ltd. by mixing with stirring at room temperature for 20 minutes to obtain a liquid thermosetting epoxy resin composition.
The gel time at 50 ° C. of the obtained liquid thermosetting epoxy resin composition was 48 minutes. In addition, as a result of thermosetting under conditions of 110 ° C. for 2 hours + 180 ° C. for 2 hours and measuring respective physical properties, the obtained resin cured product has a glass transition temperature of 137 ° C., a flexural modulus of 2275 MPa, a bending strength. Was 100 MPa, and had excellent heat resistance and bending properties. Moreover, it did not fracture in the measurement up to the deflection of 21 mm. Thus, it had practical heat resistance and excellent toughness.

Example 3
As epoxy compound (D1), 3,4-epoxycyclohexylmethyl (3,4-epoxy) cyclohexanecarboxylate [manufactured by Daicel Chemical Industries, Ltd., trade name “Celoxide 2021P”], 30 parts by weight, aromatic glycidyl ether type epoxy As compound (D2), bisphenol A type epoxy resin [manufactured by Nippon Steel Chemical Co., Ltd., trade name “Epototo YD128”] 70 parts by weight, as amine curing agent (B), isophoronediamine [Evonik Degussa Japan Co., Ltd. , Trade name “Vestamine IPD”] 25.3 parts by weight.
These were blended using “Awatori Netaro” manufactured by Shinky Co., Ltd. by mixing with stirring at room temperature for 20 minutes to obtain a liquid thermosetting epoxy resin composition.
The gel time at 50 ° C. of the obtained liquid thermosetting epoxy resin composition was 95 minutes. In addition, as a result of thermosetting under conditions of 110 ° C. for 2 hours + 180 ° C. for 2 hours and measuring respective physical properties, the obtained resin cured product has a glass transition temperature of 79 ° C., a flexural modulus of 3047 MPa, a bending strength. Was 120 MPa and had excellent heat resistance and bending properties. Moreover, it did not fracture in the measurement up to the deflection of 21 mm. Thus, it had practical heat resistance and excellent toughness.

Comparative Example 1
As aromatic glycidyl ether type epoxy compound (D2), bisphenol A type epoxy resin [manufactured by Nippon Steel Chemical Co., Ltd., trade name “Epototo YD128”] 100 parts by weight, as amine curing agent (B), isophoronediamine [Evonik] 23 parts by weight of Degussa Japan Co., Ltd., trade name “Vestamine IPD” was used.
These were blended using “Awatori Netaro” manufactured by Shinky Co., Ltd. by mixing with stirring at room temperature for 20 minutes to obtain a liquid thermosetting epoxy resin composition.
The gel time at 50 ° C. of the obtained liquid thermosetting epoxy resin composition was as short as 27 minutes. Moreover, as a result of thermosetting under the conditions of 110 ° C. for 2 hours + 180 ° C. for 2 hours and measuring the respective physical properties, the obtained resin cured product is hard and brittle with a glass transition temperature of 158 ° C., bending The elastic modulus was 2376 MPa and the bending strength was 106 MPa. Moreover, it broke by the measurement to the deflection of 21 mm.

Example 4
As epoxy compound (D1), 3,4-epoxycyclohexylmethyl (3,4-epoxy) cyclohexanecarboxylate [manufactured by Daicel Chemical Industries, Ltd., trade name “Celoxide 2021P”], 100 parts by weight, amine curing agent (B) As an isophorone diamine [Evonik Degussa Japan Co., Ltd., trade name “Vestamine IPD”] 32.8 parts by weight, as a curing accelerator (C), boron trifluoride piperidine [Stella Chemifa Co., Ltd.] 2 parts by weight Was used.
These were blended using “Awatori Netaro” manufactured by Shinky Co., Ltd. by mixing with stirring at room temperature for 20 minutes to obtain a liquid thermosetting epoxy resin composition.
The gel time at 50 ° C. of the obtained liquid thermosetting epoxy resin composition was 191 minutes or more. Moreover, as a result of thermosetting under conditions of 80 ° C. for 2 hours + 200 ° C. for 2 hours and measuring respective physical properties, the obtained resin cured product has a glass transition temperature of 159 ° C., a flexural modulus of 3476 MPa, a bending strength. Was 105 MPa and had excellent heat resistance and bending properties.

Example 5
As epoxy compound (D1), 3,4-epoxycyclohexylmethyl (3,4-epoxy) cyclohexanecarboxylate [manufactured by Daicel Chemical Industries, Ltd., trade name “Celoxide 2021P”], 30 parts by weight, aromatic glycidyl ether type epoxy As compound (D2), bisphenol A type epoxy resin [manufactured by Nippon Steel Chemical Co., Ltd., trade name “Epototo YD128”] 70 parts by weight, as amine curing agent (B), isophoronediamine [Evonik Degussa Japan Co., Ltd. , Trade name “Vestamine IPD”] 25.9 parts by weight, and 2 parts by weight of boron trifluoride piperidine [manufactured by Stella Chemifa Co., Ltd.] as the curing accelerator (C).
These were blended using “Awatori Netaro” manufactured by Shinky Co., Ltd. by mixing with stirring at room temperature for 20 minutes to obtain a liquid thermosetting epoxy resin composition.
The gel time at 50 ° C. of the obtained liquid thermosetting epoxy resin composition was 35 minutes. Moreover, as a result of thermosetting on 80 degreeC for 2 hours +200 degreeC conditions for 2 hours, and measuring each physical property, the obtained resin cured material has a glass transition temperature of 144 degreeC, a bending elastic modulus of 3151 MPa, bending strength. Was 131 MPa, and had excellent heat resistance and bending properties.

Comparative Example 2
As aromatic glycidyl ether type epoxy compound (D2), bisphenol A type epoxy resin [manufactured by Nippon Steel Chemical Co., Ltd., trade name “Epototo YD128”] 100 parts by weight, as amine curing agent (B), isophoronediamine [Evonik] 23 parts by weight of Degussa Japan Co., Ltd., trade name “Vestamine IPD” was used.
These were blended using “Awatori Netaro” manufactured by Shinky Co., Ltd. by mixing with stirring at room temperature for 20 minutes to obtain a liquid thermosetting epoxy resin composition.
The gel time at 50 ° C. of the obtained liquid thermosetting epoxy resin composition was as short as 27 minutes. Moreover, as a result of thermosetting under conditions of 80 ° C. for 2 hours + 120 ° C. for 2 hours and measuring respective physical properties, the obtained resin cured product is hard and brittle, has a glass transition temperature of 138 ° C., bending The elastic modulus was 2731 MPa and the bending strength was 120 MPa. Moreover, it broke by the measurement to the deflection of 21 mm.

  The results of Examples and Comparative Examples are summarized in Table 1. In Table 1, the numbers in the column of each component indicate parts by weight.

  As shown in Table 1, the thermosetting epoxy resin compositions of Examples 1 to 5 have a long pot life, and the cured products obtained from the resin compositions have high strength and elastic modulus. In particular, the cured products obtained from the thermosetting epoxy resin compositions of Examples 2 and 3 have high toughness. Furthermore, the thermosetting epoxy resin compositions of Examples 3 and 4 have a remarkably low viscosity and are excellent in handleability and molding workability.

  Since the curable epoxy resin composition for wind power generator blades of the present invention has a long pot life, it is easy to cast and mold large products, and the cured product obtained by thermosetting has high strength and high elasticity. Have a rate. In addition, it has practical heat resistance and high toughness. For this reason, it is useful as a resin composition for a wind power generator blade having a large blade, especially for a large composite material.

Claims (7)

  (D1) Does the epoxy group contain an epoxy compound having two or more alicyclic epoxy groups formed in the molecule containing two adjacent carbon atoms constituting the alicyclic ring, and (B) an amine curing agent? Or (C) a curable epoxy resin composition for wind power generator blades, further comprising a curing accelerator.   The curable epoxy resin composition for wind power generator blades according to claim 1, further comprising an epoxy compound (D2) containing an aromatic glycidyl ether type epoxy compound.   (A) An epoxy compound (A1) having two or more alicyclic rings in the molecule in which an epoxy group is bonded to a carbon atom constituting the ring by a single bond, and two or more diene skeletons and two or more A wind power generator containing at least one epoxy compound selected from the group consisting of an epoxidized polybutadiene resin (A2) having an epoxy group and (B) an amine curing agent, or further comprising (C) a curing accelerator A curable epoxy resin composition for blades.   The curable epoxy resin composition for wind power generator blades according to claim 3, further comprising an epoxy compound having two or more epoxy groups in the molecule (except for the above (A1) and (A2)) (D). .   The epoxy compound (D1) and the aromatic glycidyl having two or more alicyclic epoxy groups in the molecule, in which the epoxy compound (D) includes two adjacent carbon atoms constituting the alicyclic epoxy group The curable epoxy resin composition for wind power generator blades according to claim 4, which is at least one epoxy compound selected from the group consisting of ether type epoxy compounds (D2).   The curable epoxy resin composition for wind power generator blades according to any one of claims 1 to 5, wherein the amine curing agent (B) is a cycloaliphatic polyamine.   The curable epoxy resin composition for wind power generator blades according to any one of claims 1 to 6, wherein the amine curing agent (B) is isophorone diamine.