JP2023005406A - Epoxy resin composition, resin cured product, fiber-reinforced composite material, and method for producing them - Google Patents

Abstract

To provide an epoxy resin composition, a resin cured product, a fiber-reinforced composite material, and a method for producing them.SOLUTION: A two-liquid type epoxy resin composition is composed of a main agent liquid and a curing agent liquid, wherein the main agent liquid contains an epoxy resin [A] composed of a monomer containing 4 or more glycidyl groups, and an aromatic epoxy resin [B] composed of a monomer containing two or three glycidyl groups, the curing agent liquid contains a curing agent [C], the curing agent [C] contains (C-A) liquid aromatic polyamine and (C-B) solid aromatic amine containing secondary amino groups, (C-B) contains or does not contain (C-B1) solid aromatic amine having the number of secondary amino groups larger than the total number of primary amino groups and tertiary amino groups, in the case of not containing the solid aromatic amine, the curing agent [C] further contains (C-C) aliphatic cyclic polyamine, and at least one of the main agent liquid the curing agent liquid contains a resin particle component [D].SELECTED DRAWING: None

Description

TECHNICAL FIELD The present invention relates to epoxy resin compositions, cured resins, fiber-reinforced composite materials, and methods for producing these. More specifically, an epoxy resin composition that can produce a fiber-reinforced composite material having excellent heat resistance, compression properties, and impact resistance with high productivity and has a low viscosity and a long pot life, the epoxy The present invention relates to a resin cured product produced using a resin composition, a fiber-reinforced composite material produced using the epoxy resin composition, and a method for producing them.

Fiber reinforced composite materials (hereinafter also referred to as "FRP") are lightweight, high strength, and high rigidity, so they are widely used in sports and leisure applications such as fishing rods and golf shafts, and industrial applications such as automobiles and aircraft. used in the field. As a method of molding a composite material using a thermosetting resin as a matrix resin, resin transfer molding ( RTM) method, and a method of molding a prepreg (intermediate base material) formed into a sheet by impregnating a fiber-reinforced base material with a resin in advance, and the like are known.
In recent years, in particular, the RTM molding method, which is a low-cost and highly productive manufacturing method that has few processes for manufacturing fiber-reinforced composite materials and does not require expensive equipment such as an autoclave, has attracted attention. ing. The composition of the matrix resin used in the RTM molding method mainly contains an epoxy resin and a curing agent, and optionally other additives. Aromatic polyamines are generally used as curing agents in order to obtain cured products and fiber-reinforced composite materials with high mechanical properties.
In the epoxy resin composition used in the RTM molding method, the curing agent and additives are dissolved in the epoxy resin that is the main ingredient in order to prevent the curing agent from being filtered out when the epoxy resin composition is impregnated into the reinforcing fiber base material. It is often stored and used in a state where An epoxy resin composition obtained by dissolving and mixing a curing agent and an additive into a main epoxy resin is called a one-liquid type epoxy resin composition. At this time, since the curing agent exists in the state dissolved in the epoxy resin, the reaction between the epoxy resin and the curing agent is relatively likely to occur, resulting in a short shelf life of the epoxy resin composition. Therefore, the one-liquid type epoxy resin composition had to be stored frozen.
In order to solve this problem, a two-liquid type epoxy resin composition, in which an epoxy resin and a curing agent are mixed immediately before use, has been studied. A two-component epoxy resin composition is composed of a main liquid containing an epoxy resin as a main component and a curing agent liquid (curing agent composition) containing a curing agent as a main component. It is an epoxy resin composition to be mixed.

In a two-liquid type epoxy resin composition, since the base liquid and the curing agent liquid are mixed immediately before use, ease of mixing is important. The curing agent used for the one-component epoxy resin composition can be used as the curing agent for the two-component epoxy resin composition. Aromatic polyamine curing agents used in are usually solid and tend to be poorly mixed with the main liquid. Therefore, it is desirable that the curing agent composition is liquid.
As an epoxy resin composition using a liquid aromatic polyamine as a curing agent, those described in Patent Documents 2 and 3 are exemplified. However, the resin cured products obtained from the epoxy resin compositions described in Patent Documents 2 and 3 do not have mechanical properties such as elastic modulus and fracture toughness required for industrial applications such as automobiles and aircraft, and improvement thereof is desired. requested.
In addition, in the RTM method, rapid curability is required to shorten the resin curing time in order to produce fiber-reinforced composite materials with high efficiency. Patent Document 4 proposes a fast-curing two-component epoxy resin composition using a compound having two or more aromatic rings having phenolic hydroxyl groups. However, when a compound having a phenolic hydroxyl group is added to the epoxy resin composition, the viscosity of the resin composition increases rapidly due to its high reactivity, and the pot life in RTM molding is extremely shortened. It becomes difficult to impregnate the inside of the substrate with a sufficient amount of resin. Therefore, a fiber-reinforced composite material produced using such an epoxy resin composition contains many defects such as voids. As a result, there has been a problem that the compression performance and damage tolerance of the fiber-reinforced composite material structure are degraded.
In this way, a resin that has sufficient rapid curing properties to realize high productivity of fiber-reinforced composite materials and also has high levels of heat resistance and mechanical properties required for industrial applications such as automobiles and aircraft. A two-component epoxy resin composition capable of obtaining a cured product has not existed so far.

JP 2014-148572 JP 2015-193713 WO2009/119467 Patent No. 6617559

An object of the present invention is to solve the problems of the above-described conventional technology, to produce a cured resin product with excellent properties, to have high impregnability into a fiber-reinforced base material, to handle easily and to produce a fiber-reinforced composite material. An object of the present invention is to provide an epoxy resin composition having excellent productivity. A further object of the present invention is to provide a fiber-reinforced composite material (hereinafter sometimes abbreviated as "FRP") produced using this epoxy resin composition, especially when the fiber-reinforced base material is carbon fiber. (sometimes abbreviated as “CFRP”).

（ただし、化学式（１）中、Ｒ₁～Ｒ₄は、それぞれ独立に、水素原子、脂肪族炭化水素基、脂環式炭化水素基、及びハロゲン原子からなる群から選択される１つを表し、Ｘは－ＣＨ₂－、－Ｏ－、－Ｓ－、－ＣＯ－、－Ｃ（＝Ｏ）Ｏ－、－Ｏ－Ｃ（＝Ｏ）－、－ＮＨＣＯ－、－ＣＯＮＨ－、－ＳＯ₂－から選択される１つを表す。）
で示される化合物を含んで成る、前記〔１〕に記載の２液型エポキシ樹脂組成物。
〔３〕
前記エポキシ樹脂［Ａ］の構成モノマーが、テトラグリシジル－４,４’－ジアミノジフェニルエーテル、テトラグリシジル－４,４’－ジアミノジフェニルメタン、テトラグリシジル－３,４’－ジアミノジフェニルエーテルもしくはテトラグリシジル－３,３’－ジアミノジフェニルメタンから選択される１種類または２種以上の組み合わせである、前記〔１〕または〔２〕に記載の２液型エポキシ樹脂組成物。
〔４〕
前記主剤液が、前記エポキシ樹脂［Ａ］を５０～９０質量％含んで成る、前記〔１〕～〔３〕のいずれか１項に記載の２液型エポキシ樹脂組成物。
〔５〕
前記エポキシ樹脂［Ｂ］の構成モノマーが、ジグリシジルアニリン、ジグリシジル－ｏ－トルイジン、トリグリシジル－ｐ－アミノフェノール、トリグリシジル－ｍ－アミノフェノール、ビス(グリシジルオキシ)ナフタレンおよびトリグリシジルイソシアヌレートから選択される１種類または２種以上の組み合わせである、前記〔１〕～〔４〕のいずれか１項に記載の２液型エポキシ樹脂組成物。
〔６〕前記樹脂粒子成分［Ｄ］の平均粒子径が１．０μｍ以下である、前記〔１〕～〔５〕のいずれか１項に記載の２液型エポキシ樹脂組成物。
〔７〕
前記〔１〕～〔６〕のいずれか１項に記載の２液型エポキシ樹脂組成物の前記主剤液と前記硬化剤液とを配合して成る、１液型エポキシ樹脂組成物。
〔８〕
誘電硬化度測定によって評価される、１８０℃４０分加熱後の硬化度が７０％以上である、前記〔７〕に記載の１液型エポキシ樹脂組成物。
〔９〕
前記〔７〕又は〔８〕に記載の１液型エポキシ樹脂組成物を硬化して成る樹脂硬化物。
〔１０〕
変形モードＩ臨界応力拡大係数ＫＩｃが０．８以上である、前記〔９〕に記載の樹脂硬化物。
〔１１〕
前記〔９〕又は〔１０〕に記載の樹脂硬化物と、繊維強化基材と、を含んで構成される繊維強化複合材料。
〔１２〕
前記繊維強化基材が炭素繊維強化基材である、前記〔１１〕に記載の繊維強化複合材料。
〔１３〕
繊維強化基材と、前記〔７〕又は〔８〕に記載の１液型エポキシ樹脂組成物と、を複合化して硬化させる、繊維強化複合材料の製造方法。
〔１４〕
前記〔７〕又は〔８〕に記載の１液型エポキシ樹脂組成物を、型内に配置した繊維強化基材へ含浸させた後、加熱硬化する工程を含む、繊維強化複合材料の製造方法。 As a result of investigations aimed at solving the above problems, the inventors of the present invention have found that a two-component epoxy resin composed of a combination of a base liquid containing a predetermined epoxy resin, a curing agent liquid containing a predetermined curing agent, and a resin particle component. The inventors have found that the above problems can be solved by using the composition, and have completed the present invention.
That is, the present invention can include the following aspects.
[1]
A two-liquid type epoxy resin composition comprising a base liquid and a curing agent liquid,
The main component liquid contains an epoxy resin [A] composed of a monomer containing 4 or more glycidyl groups, and an aromatic epoxy resin [B] composed of a monomer containing 2 or 3 glycidyl groups,
The curing agent liquid contains a curing agent [C], the curing agent [C] contains (CA) a liquid aromatic polyamine and (C-B) a solid aromatic amine containing a secondary amino group, ( CB) a solid aromatic amine comprising secondary amino groups comprises (C-B1) a solid aromatic amine in which the number of secondary amino groups is greater than the total number of primary and tertiary amino groups, or If not included, if not included, the curing agent [C] further includes (C-C) aliphatic cyclic polyamine,
A two-liquid type epoxy resin composition, wherein at least one of the main liquid and the curing agent liquid contains a resin particle component [D].
[2]
The constituent monomer of the epoxy resin [A] has the following chemical formula (1)

(In chemical formula (1), R ₁ to R ₄ each independently represent one selected from the group consisting of a hydrogen atom, an aliphatic hydrocarbon group, an alicyclic hydrocarbon group, and a halogen atom. , X is -CH ₂ -, -O-, -S-, -CO-, -C(=O)O-, -O-C(=O)-, -NHCO-, -CONH-, -SO ₂ represents one selected from -.)
The two-component epoxy resin composition according to [1] above, comprising a compound represented by
[3]
The constituent monomer of the epoxy resin [A] is tetraglycidyl-4,4'-diaminodiphenyl ether, tetraglycidyl-4,4'-diaminodiphenylmethane, tetraglycidyl-3,4'-diaminodiphenyl ether or tetraglycidyl-3,3 The two-component epoxy resin composition according to [1] or [2] above, which is one or a combination of two or more selected from '-diaminodiphenylmethane.
[4]
The two-component epoxy resin composition according to any one of [1] to [3], wherein the main liquid contains 50 to 90% by mass of the epoxy resin [A].
[5]
The constituent monomer of the epoxy resin [B] is selected from diglycidylaniline, diglycidyl-o-toluidine, triglycidyl-p-aminophenol, triglycidyl-m-aminophenol, bis(glycidyloxy)naphthalene and triglycidyl isocyanurate. The two-component epoxy resin composition according to any one of [1] to [4] above, which is one or a combination of two or more.
[6] The two-component epoxy resin composition according to any one of [1] to [5] above, wherein the resin particle component [D] has an average particle size of 1.0 μm or less.
[7]
A one-component epoxy resin composition obtained by blending the main component liquid and the curing agent liquid of the two-component epoxy resin composition according to any one of [1] to [6].
[8]
The one-component epoxy resin composition according to [7] above, which has a degree of curing of 70% or more after heating at 180° C. for 40 minutes, as evaluated by dielectric curing degree measurement.
[9]
A cured resin obtained by curing the one-liquid type epoxy resin composition according to [7] or [8] above.
[10]
The cured resin product according to [9] above, which has a deformation mode I critical stress intensity factor KIc of 0.8 or more.
[11]
A fiber-reinforced composite material comprising the cured resin according to [9] or [10] and a fiber-reinforced base material.
[12]
The fiber-reinforced composite material according to [11] above, wherein the fiber-reinforced base material is a carbon fiber-reinforced base material.
[13]
A method for producing a fiber-reinforced composite material, comprising combining a fiber-reinforced base material and the one-component epoxy resin composition according to [7] or [8] above and curing the composition.
[14]
A method for producing a fiber-reinforced composite material, comprising a step of impregnating a fiber-reinforced base material placed in a mold with the one-component epoxy resin composition according to [7] or [8], followed by heat curing.

The two-liquid type epoxy resin composition of the present invention can produce a resin cured product having excellent properties. In addition, the one-component epoxy resin obtained by mixing the main component liquid and the curing agent liquid of the two-component epoxy resin composition of the present invention has a low viscosity, a long pot life, high handleability, and a curing time. is short, FRP with excellent properties can be produced with high productivity.

Details of the epoxy resin composition, the fiber-reinforced composite material, and the method for producing them of the present invention are described below. In this specification, unless otherwise specified, the term "epoxy resin composition" includes both one-component epoxy resin compositions and two-component epoxy resin compositions.
1. Epoxy resin composition The two-component epoxy resin composition of the present invention comprises a main liquid and a curing agent liquid, wherein the main liquid is an epoxy resin [A] composed of a monomer containing 4 or more glycidyl groups, and an aromatic epoxy resin [B] composed of a monomer containing two or three glycidyl groups, the curing agent liquid containing a curing agent [C], and the curing agent [C] being (CA ) a liquid aromatic polyamine and (C-B) a solid aromatic amine containing a secondary amino group, wherein (C-B) a solid aromatic amine containing a secondary amino group comprises (C-B1) a secondary amino group contains or does not contain a solid aromatic amine whose number is greater than the total number of primary amino groups and tertiary amino groups. At least one of the main liquid and the curing agent liquid contains the resin particle component [D]. In the two-liquid type epoxy resin composition of the present invention, in addition to these, the main liquid may contain an epoxy resin other than the epoxy resins [A] and [B], a thermosetting resin other than the epoxy resin, and a curing agent liquid. may contain a curing agent other than the curing agent [C], and the main component liquid and the curing agent liquid may contain thermoplastic resins other than the resin particle component [D] and other additives.

The one-liquid type epoxy resin composition of the present invention is formed by blending the main liquid of the two-liquid type epoxy resin composition of the present invention and the curing agent liquid, and comprises epoxy resins [A] and [B] and curing agent [C]. ] and the resin particle component [D].
The one-component epoxy resin composition of the present invention preferably has an initial viscosity at 100° C. of 300 mPa·s or less, more preferably 0.1 to 150 mPa·s, and more preferably 0.5 to 70 mPa·s. and more preferably 1.0 to 50 mPa·s. When the initial viscosity at 100° C. is 300 mPa·s or less, it is easy to impregnate the reinforcing fiber base material with the one-component epoxy resin composition. As a result, it is possible to prevent the formation of voids and the like that cause deterioration of physical properties in the resulting fiber-reinforced composite material. Note that the relationship between the viscosity and the impregnability depends on the structure of the reinforcing fiber base material, and even if the viscosity is outside the above range, the impregnation of the reinforcing fiber base material may be good in some cases.
In addition, the pot life of the one-liquid type epoxy resin composition varies depending on the molding conditions of the composite material. When the fiber base material is impregnated with, the pot life is preferably 30 minutes or more, and preferably 60 minutes or more, until the viscosity reaches 50 mPa s when held at 100 ° C. More preferably, it is 90 minutes or longer.
In addition, the degree of curing of the one-component epoxy resin composition after heating at 180° C. for 40 minutes, which is evaluated by dielectric curing measurement, is preferably 70% or more, preferably 80%, from the viewpoint of productivity of fiber-reinforced composite materials. It is more preferably 90% or more, and more preferably 90% or more.

The resin cured product obtained by curing the one-liquid epoxy resin composition of the present invention has a glass transition temperature (dry-Tg) of 140° C. or more in a dry state of the test piece measured by the SACMA 18R-94 method. is preferred, 170° C. or higher is more preferred, and 180° C. or higher is even more preferred. In addition, the resin cured product obtained by curing the one-liquid epoxy resin composition of the present invention has a glass transition temperature (wet-Tg) of 120° C. or higher when the test piece has saturated water absorption measured by the SACMA 18R-94 method. , more preferably 130 to 200°C, even more preferably 150 to 180°C.
In addition, the resin cured product obtained by curing the one-liquid type epoxy resin composition of the present invention preferably has a room-temperature dry flexural modulus of 2.8 GPa or more as measured by the JIS K7171 method, preferably 3.0 to 15. 0 GPa, more preferably 3.2 to 10.0 GPa, even more preferably 3.5 to 7.5 GPa. When it is 2.8 GPa or more, the fiber-reinforced composite material obtained using the one-liquid type epoxy resin composition of the present invention has excellent properties. The resin cured product obtained by curing the one-liquid type epoxy resin composition of the present invention has a flexural modulus after water absorption at 82°C (HTW-FM) measured by the JIS K7171 method of 2.0 GPa or more. It is preferably 2.1 to 9.0 GPa, more preferably 2.2 to 8.0 GPa.
In addition, the resin cured product obtained by curing the one-liquid type epoxy resin composition of the present invention should have a deformation mode I critical stress intensity factor KIc measured by ASTM D5045 of 0.8 MPa·m^1/2 or more. is preferred, and 0.81 to 5.0 MPa·m^1/2 is more preferred.

The carbon fiber reinforced composite material obtained by combining the one-component epoxy resin composition of the present invention with carbon fibers preferably has a post-impact compressive strength CAI (impact energy 30.5 J) measured by ASTM D7136 of 250 MPa or more. , 260 to 400 MPa, more preferably 280 to 380 MPa.
The carbon fiber reinforced composite material obtained by combining the one-component epoxy resin composition of the present invention and carbon fiber preferably has a room temperature dry open-hole compressive strength (RTD-OHC) of 260 MPa or more as measured by SACMA SRM3. It is more preferably 280 to 450 MPa, even more preferably 300 to 400 MPa. In addition, the carbon fiber reinforced composite material obtained by combining the one-liquid epoxy resin composition of the present invention with carbon fiber has an open hole compressive strength (HTW-OHC) after water absorption at 82°C measured by SACMA SRM3 of 200 MPa or more. is preferably 220 to 400 MPa, and even more preferably 240 to 350 MPa.
The total amount of the curing agent [C] contained in the epoxy resin composition is an amount suitable for curing all the epoxy resins blended in the epoxy resin composition, and varies depending on the type of epoxy resin and curing agent used. adjusted accordingly. Specifically, the ratio of the number of epoxy groups contained in the epoxy resin in the epoxy resin composition to the number of active hydrogens contained in the amine curing agent is 0.7 to 1.3, more preferably 0.8 to 1.2, more preferably 0.9 to 1.1. If the ratio of the number of epoxy groups contained in the epoxy resin in the epoxy resin composition to the number of active hydrogens contained in the amine curing agent is 0.7 to 1.3, the moles of appropriate epoxy groups and active hydrogens Due to the balance, the cured resin obtained has a sufficient crosslink density, and desired heat resistance, and mechanical properties such as elastic modulus and fracture toughness can be obtained.

（ただし、化（１）中、Ｒ₁～Ｒ₄は、それぞれ独立に、水素原子、脂肪族炭化水素基、脂環式炭化水素基、ハロゲン原子からなる群から選ばれる１つを表し、Ｘは－ＣＨ₂－、－Ｏ－、－Ｓ－、－ＣＯ－、－Ｃ（＝Ｏ）Ｏ－、－Ｏ－Ｃ（＝Ｏ）－、－ＮＨＣＯ－、－ＣＯＮＨ－、－ＳＯ₂－から選ばれる１つを表す。）
Ｒ₁～Ｒ₄が、脂肪族炭化水素基又は脂環式炭化水素基である場合、その炭素数は１～４であることが好ましい。 1-1. epoxy resin [A]
The epoxy resin composition of the present invention contains an epoxy resin [A] composed of a monomer containing 4 or more glycidyl groups. The epoxy resin [A] may be a homopolymer composed of one type of monomer, may be a copolymer composed of two or more types of monomers, or may be a mixture of homopolymers and/or copolymers. good too. The epoxy resin composition of the present invention preferably contains an epoxy resin [A] whose constituent monomer is represented by the following chemical formula (1).

(In formula (1), R ₁ to R ₄ each independently represent one selected from the group consisting of a hydrogen atom, an aliphatic hydrocarbon group, an alicyclic hydrocarbon group and a halogen atom, and X is -CH ₂ -, -O-, -S-, -CO-, -C(=O)O-, -O-C(=O)-, -NHCO-, -CONH-, -SO ₂ - represents the chosen one.)
When R ₁ to R ₄ are aliphatic hydrocarbon groups or alicyclic hydrocarbon groups, they preferably have 1 to 4 carbon atoms.

Constituent monomers of the epoxy resin [A] include tetraglycidyl-4,4'-diaminodiphenyl ether, tetraglycidyl-4,4'-diaminodiphenylmethane, tetraglycidyl-3,4'-diaminodiphenyl ether and tetraglycidyl-3,3. One or a combination of two or more selected from '-diaminodiphenylmethane is particularly preferred. That is, the epoxy resin [A] is preferably a homopolymer, copolymer, or mixture thereof composed of these monomers. When R ₁ to R ₄ are hydrogen atoms, it is preferable because formation of a special steric structure of the cured resin is less likely to be inhibited. In addition, it is preferable that X is -O- because the synthesis of the compound is facilitated.
The constituent monomers of the epoxy resin [A] may be synthesized by any method. to obtain a tetrahalohydrin compound, followed by a cyclization reaction using an alkaline compound. More specifically, it can be synthesized by the method described in Examples below.
Examples of aromatic diamines include 4,4′-diaminodiphenyl ether, 3,3′-diaminodiphenyl ether, 3,4′-diaminodiphenyl ether, 4,4′-diaminodiphenyl sulfone, 3,3′-diaminodiphenyl sulfone, 3 , 4′-diaminodiphenyl sulfone, 4,4′-diaminodiphenyl methane, and the like. Among these, from the viewpoint of heat resistance, aromatic diamines in which two aromatic rings having amino groups are linked by an ether bond are preferable, one amino group is para-positioned with respect to the ether bond, and the other amino group is More preferably, it is an ortho-located aromatic diamine. Examples of such aromatic diamines include 3,4'-diaminodiphenyl ether.
Epihalohydrin includes, for example, epichlorohydrin, epibromohydrin, epifluorohydrin, and the like. Among these, epichlorohydrin and epibromohydrin are particularly preferred from the viewpoint of reactivity and handleability.
The mass ratio of the raw materials, aromatic diamine and epihalohydrin, is preferably 1:1 to 1:20, more preferably 1:3 to 1:10. Solvents used for the reaction include alcohol solvents such as ethanol and n-butanol, ketone solvents such as methyl isobutyl ketone and methyl ethyl ketone, aprotic polar solvents such as acetonitrile and N,N-dimethylformamide, and toluene and xylene. Aromatic hydrocarbon solvents are exemplified. Alcohol solvents such as ethanol and n-butanol, and aromatic hydrocarbon solvents such as toluene and xylene are particularly preferred. The amount of solvent to be used is preferably 1 to 10 times the weight of the aromatic diamine. Both Bronsted acids and Lewis acids can be suitably used as acid catalysts. Preferred Bronsted acids are ethanol, water and acetic acid, and preferred Lewis acids are titanium tetrachloride, lanthanum nitrate hexahydrate and boron trifluoride diethyl ether complex.

The reaction time is preferably 0.1 to 180 hours, more preferably 0.5 to 24 hours. The reaction temperature is preferably 20-100°C, more preferably 40-80°C.
Examples of alkaline compounds used in the cyclization reaction include sodium hydroxide and potassium hydroxide. The alkaline compound may be added as a solid or as an aqueous solution.
A phase transfer catalyst may be used during the cyclization reaction. Phase transfer catalysts include quaternary ammonium salts such as tetramethylammonium chloride, tetraethylammonium bromide, benzyltriethylammonium chloride, and tetrabutylammonium hydrogen sulfate; phosphonium compounds such as tributylhexadecylphosphonium bromide and tributyldodecylphosphonium bromide; Examples include crown ethers such as 18-crown-6-ether.
The epoxy resin [A] used in the present invention preferably has a viscosity at 50° C. of less than 50 Pa·s, more preferably less than 30 Pa·s, still more preferably less than 20 Pa·s, and 10 Pa·s. It is particularly preferred that it is less than s.
The molecular weight of epoxy resin [A] is preferably 300 g/mol or more and less than 600 g/mol. If the molecular weight is within the above range, the viscosity of the epoxy resin composition can be lowered, which is advantageous for RTM molding.
The proportion of the epoxy resin [A] in the main liquid of the two-component epoxy resin composition of the present invention is 10% by mass or more and less than 100% by mass with respect to the total mass of the epoxy resin in the main liquid. It is preferably from 50 to 90% by mass, and even more preferably from 60 to 80% by mass. If the proportion of the epoxy resin [A] is 10% by mass or more, the heat resistance and elastic modulus of the obtained cured resin can be further improved. As a result, various physical properties of the resulting fiber-reinforced composite material are also improved.

1-2. epoxy resin [B]
The epoxy resin composition of the present invention contains an aromatic epoxy resin [B] composed of a monomer containing two or three glycidyl groups. The epoxy resin [B] lowers the viscosity of the one-liquid epoxy resin composition and improves the impregnation of the reinforcing fiber substrate with the resin.
The constituent monomer of the epoxy resin [B] is not particularly limited as long as it is an aromatic compound having two or three glycidyl groups. Examples of aromatic compounds having two glycidyl groups include diglycidylaniline and derivatives thereof. Certain diglycidyl-o-toluidine, diglycidyl-m-toluidine, diglycidyl-p-toluidine, diglycidyl-xylidine, diglycidyl-mesidine, diglycidyl-anisidine, diglycidyl-phenoxyaniline or diglycidyl-naphthylamine and derivatives thereof are preferably used.
In particular, diglycidyl-aniline, diglycidyl-o-toluidine, diglycidyl-m-toluidine, diglycidyl-p-toluidine and diglycidyl-phenoxyaniline are more preferably used, and diglycidyl-aniline or diglycidyl-o-toluidine is more preferably used. When an epoxy resin having these compounds as constituent monomers is used as the epoxy resin [B], the pot life of the one-liquid epoxy resin composition can be extended, and the degree of freedom in designing the mold used in the RTM molding method can be increased. can be enhanced.
Moreover, it is also preferable that the constituent monomers of the epoxy resin [B] contain a compound having a polycyclic aromatic hydrocarbon skeleton as an aromatic epoxy resin having two or three glycidyl groups. Examples of the polycyclic aromatic hydrogen cyclic skeleton include a naphthalene skeleton and an anthracene skeleton, and a naphthalene skeleton is more preferable from the viewpoint of the physical properties of the cured resin. The polycyclic aromatic hydrocarbon group may have a substituent other than the glycidyl group. Compounds having a naphthalene skeleton include 1,6-bis(glycidyloxy)naphthalene, 1,5-bis(glycidyloxy)naphthalene, 2,6-bis(glycidyloxy)naphthalene, and 2,7-bis(glycidyloxy) Bis(glycidyloxy)naphthalene such as naphthalene, 2,2'-bis(glycidyloxy)-1,1'-binaphthalene, 2,7-bis(glycidyloxy)-1-[2-(glycidyloxy)-1 Epoxy resins having a binaphthalene structure such as -naphthylmethyl]naphthalene are included, and bis(glycidyloxy)naphthalene is particularly preferred from the viewpoint of fluidity. The epoxy resin [B] containing these compounds as constituent monomers can reduce the viscosity of the one-liquid type epoxy resin composition and improve the heat resistance of the cured resin.

Epoxy resin [B] does not excessively increase the crosslink density of the cured product, unlike tetrafunctional epoxy resins that are usually used to improve the heat resistance of the cured product. Therefore, it is possible to prevent a decrease in toughness of the cured resin.
Moreover, it is also preferable that the constituent monomer of the epoxy resin [B] contains a triglycidylaminophenol derivative as an aromatic compound having three glycidyl groups. Triglycidylaminophenol derivatives include triglycidyl-m-aminophenol and triglycidyl-p-aminophenol. These reduce the viscosity of the one-component epoxy resin composition and improve the heat resistance of the cured resin. Therefore, by using it in combination with the epoxy resin [A], the resin-impregnated property of the one-liquid epoxy resin composition into the reinforcing fiber base material is improved, and the cured resin and fiber that maintain heat resistance and high elastic modulus Provides reinforced composites.
Moreover, it is also preferable that the constituent monomers of the epoxy resin [B] include a triglycidyl isocyanurate derivative epoxy resin as a heteroaromatic compound epoxy resin having three glycidyl groups. Triglycidyl isocyanurate derivative epoxy resins include 1,3,5-triglycidyl isocyanurate, 1,3,5-tri(ethylglycidyl) isocyanurate, and 1,3,5-tri(pentylglycidyl) isocyanurate. be done. These improve the heat resistance and elastic modulus of the cured epoxy resin. Therefore, by using it in combination with the epoxy resin [A], a cured resin and a fiber-reinforced composite material maintaining heat resistance and high elastic modulus can be obtained.
In the present invention, the constituent monomers of the epoxy resin [B] include diglycidylaniline, diglycidyl-o-toluidine, bis(glycidyloxy)naphthalene, triglycidyl-p-aminophenol, triglycidyl-m-aminophenol and triglycidylisocyanate. It is particularly preferred to contain one or a combination of two or more selected from nurates. That is, it is particularly preferred that the epoxy resin [B] is a homopolymer, copolymer, or mixture thereof composed of these monomers.
Other examples of the epoxy resin [B] include bisphenol A-type epoxy resin, bisphenol F-type epoxy resin, bisphenol S-type epoxy resin, phenol novolac-type epoxy resin, cresol novolak-type epoxy resin, and the like.
The viscosity of the epoxy resin [B] at 120° C. measured with a Brookfield viscometer is preferably less than 100 mPa s, particularly preferably less than 50 mPa s, and further preferably less than 20 mPa s. preferable. If the viscosity is within the above range, the viscosity of the epoxy resin composition can be lowered, which is advantageous for RTM molding.
The content of the epoxy resin [B] in the main liquid of the two-component epoxy resin composition of the present invention is preferably 3 to 50% by mass with respect to the total mass of the epoxy resin in the main liquid. It is more preferably from 5 to 40% by mass, and particularly preferably from 5 to 40% by mass. By setting the content of the epoxy resin [B] in the main liquid to this range, it is possible to obtain cured resins and fiber-reinforced composite materials that have a viscosity and pot life suitable for the RTM molding method and have high heat resistance. A one-component epoxy resin composition can be prepared.

1-3. Curing agent [C]
The epoxy resin composition of the present invention contains a curing agent [C], and the curing agent [C] comprises (C-A) a liquid aromatic polyamine and (C-B) a solid aromatic amine containing a secondary amino group. (C-B) a solid aromatic amine containing secondary amino groups is (C-B1) a solid aromatic amine in which the number of secondary amino groups is greater than the total number of primary and tertiary amino groups It may or may not be included, and if not included, the curing agent [C] further includes (CC) aliphatic cyclic polyamine.

(CA) Liquid Aromatic Polyamine The “liquid” aromatic polyamine in the present invention refers to an aromatic polyamine that has a melting point lower than room temperature (25° C.), ie, is in a liquid state at room temperature (25° C.).

A liquid aromatic polyamine is an aromatic compound having two or more amino groups. In the present specification, unless otherwise specified, "amino group" includes "primary amino group", "secondary amino group" and "tertiary amino group". Since the tertiary amino group promotes the self-polymerization of the epoxy resin and tends to lower the heat resistance of the resulting cured product, from the viewpoint of obtaining a highly heat-resistant cured product, the liquid aromatic polyamine is It preferably contains a primary amino group, two or more secondary amino groups, or one or more primary amino groups and one or more secondary amino groups.

The liquid aromatic polyamine preferably has a viscosity of 100 cP or less, more preferably 0.001 to 60 cP, and still more preferably 0.001 to 60 cP under heating conditions of 80° C. or higher, from the viewpoint of lowering the viscosity of the one-component epoxy resin composition. has a viscosity of 0.01-20 cP. The viscosity of the liquid aromatic polyamine can be measured using a commercially available viscosity measuring device such as RheoStress 6000 manufactured by HAAKE.

The liquid aromatic polyamine preferably has a boiling point of 140.degree. C. or higher, more preferably 150.degree. If the boiling point is 140° C. or higher, it is sufficiently higher than the temperature at which the reinforcing fibers are impregnated with the one-component epoxy resin composition in the manufacturing process of the fiber-reinforced composite material using the epoxy resin as the matrix resin. volatilization of the group polyamine component can be suppressed, and as a result, structural defects and reduction in strength of the fiber-reinforced composite material can be suppressed.

Preferred liquid aromatic polyamines include, for example, dimethylthiotoluenediamine, diethyltoluenediamine, 4,4'-methylenebis[N-(1-methylpropyl)aniline] and the like.

Examples of commercially available liquid aromatic polyamines include dimethylthiotoluenediamine (“Etacure 300” manufactured by Albemarle, “Heartcure 30” manufactured by Kumiai Chemical Industry Co., Ltd.), diethyltoluene diamine (“Etacure 100 Plus” manufactured by Albemarle), "Heart Cure 10" manufactured by Kumiai Chemical Industry Co., Ltd.) and the like.

The liquid aromatic polyamines may be used singly or in combination of two or more. When two or more types of liquid aromatic polyamines are used in combination, from the viewpoint of enhancing the strength and heat resistance of the cured product, liquid aromatic polyamines containing two or more primary amino groups are added to the total mass of the liquid aromatic amines. The group polyamine is preferably contained in a proportion of 50 to 90% by mass, more preferably in a proportion of 60 to 80% by mass.

When the curing agent [C] is 100% by mass, the liquid aromatic polyamine is preferably 40 to 97% by mass, more preferably 50 to 95% by mass, from the viewpoint of obtaining a low-viscosity one-component epoxy resin composition. , more preferably in an amount of 55 to 93% by mass in the curing agent [C].

(C-B) Solid Aromatic Amines Containing Secondary Amino Groups A “solid” aromatic amine in the present invention has a melting point higher than room temperature (25° C.), i.e., is in a solid state at room temperature (25° C.) Aromatic amines.

The solid aromatic amines of the present invention contain secondary amino groups. By including a secondary amino group in the solid aromatic amine, the impact strength of the cured product can be increased.

The solid aromatic amine containing a secondary amino group preferably has a melting point of 160°C or less, for example 155°C or less, or preferably 150°C or less. Moreover, the solid aromatic amine containing a secondary amino group preferably has a melting point of, for example, 30° C. or higher, 40° C. or higher, 50° C. or higher, 60° C. or higher, or 70° C. or higher. If the melting point is 160° C. or less, it can be easily dissolved in a liquid aromatic polyamine in a short time.

Examples of the solid aromatic amine containing a secondary amino group having a melting point of 160° C. or lower include N-phenyl-1-naphthylamine, octylated diphenylamine, 4,4′-bis(α,α-dimethylbenzyl)diphenylamine, N -(p-tolyl)-1-naphthylamine, N-phenyl-3-biphenylamine, bis(3-biphenylyl)amine, 2-(3-biphenylyl)amino-9,9-dimethylfluorene, bis(4-tert- butylphenyl)amine, 4-tert-butylphenylphenylamine, bis-α-methylbenzylphenothiazine, reaction products of diphenylamine and 2,4,4-trimethylpentene, diphenylamine, N-phenylbenzylamine, 3-methyldiphenylamine, 3,4-dimethyldiphenylamine, 4,4'-dimethyldiphenylamine, 3-methoxydiphenylamine, 10-methoxy-2,2'-iminostilbene, N-benzyl-2-naphthylamine, 1,2'-dinaphthylamine, 1, 1'-dinaphthylamine, 4-isopropylaminodiphenylamine, 2,6-bis[(2-hydroxyethyl)amino]toluene, 4-(2-octylamino)diphenylamine, N-(1,3-dimethylbutyl)-N '-Phenyl-1,4-phenylenediamine, 2,2,4-trimethyl-1,2-dihydroquinoline polymer, 1,3-diphenylguanidine, p-(p-toluenesulfonylamido)diphenylamine, N-phenyl- N'-(3-methacryloyloxy-2-hydroxypropyl)-p-phenylenediamine, bis(2-benzamidophenyl)disulfide, N,N'-diphenyl-1,4-phenylenediamine, N,N'-diphenylethylenediamine , 5-(acetoacetamido)-2-benzimidazolinone, 1-(o-tolyl)biguanide, phenylbiguanide, polymeric biguanide compounds containing terminal amino groups, 4-phenylsemicarbazide, 4-phenyl-3-thiosemicarbazide, 1,2,3-triphenylguanidine and the like.

The solid aromatic amine containing a secondary amino group preferably has a boiling point of 140°C or higher, more preferably 145°C to 550°C, still more preferably 150°C to 500°C, still more preferably 160°C to 450°C. , particularly preferably having a boiling point of from 170 to 400°C. If the boiling point is 140° C. or higher, it is sufficiently higher than the temperature at which the reinforcing fibers are impregnated with the one-component epoxy resin composition in the manufacturing process of the fiber-reinforced composite material using the epoxy resin as the matrix resin. Volatilization of the solid aromatic amine component containing amino groups can be suppressed, and as a result, structural defects and reduction in strength of the fiber-reinforced composite material can be suppressed.

Examples of the solid aromatic amine containing a secondary amino group having a boiling point of 140° C. or higher include N-phenyl-1-naphthylamine, octylated diphenylamine, 4,4′-bis(α,α-dimethylbenzyl)diphenylamine, N -(p-tolyl)-1-naphthylamine, N-phenyl-3-biphenylamine, bis(3-biphenylyl)amine, 2-(3-biphenylyl)amino-9,9-dimethylfluorene, bis(4-tert- butylphenyl)amine, 4-tert-butylphenylphenylamine, bis-α-methylbenzylphenothiazine, reaction products of diphenylamine and 2,4,4-trimethylpentene, diphenylamine, N-phenylbenzylamine, 3-methyldiphenylamine, 3,4-dimethyldiphenylamine, 4,4'-dimethyldiphenylamine, 3-methoxydiphenylamine, 10-methoxy-2,2'-iminostilbene, N-benzyl-2-naphthylamine, 1,2'-dinaphthylamine, 1, 1'-dinaphthylamine, 4-isopropylaminodiphenylamine, 2,6-bis[(2-hydroxyethyl)amino]toluene, 4-(2-octylamino)diphenylamine, N-(1,3-dimethylbutyl)-N '-Phenyl-1,4-phenylenediamine, 2,2,4-trimethyl-1,2-dihydroquinoline polymer, 1,3-diphenylguanidine, p-(p-toluenesulfonylamido)diphenylamine, N-phenyl- N'-(3-methacryloyloxy-2-hydroxypropyl)-p-phenylenediamine, bis(2-benzamidophenyl)disulfide, N,N'-diphenyl-1,4-phenylenediamine, 1,3-di-o -tolylguanidine, 1,5-diphenylcarbonohydrazide, N,N'-diphenylethylenediamine, 5-(acetoacetamido)-2-benzimidazolinone, 1-(o-tolyl)biguanide, 1-phenylguanidine, phenylbiguanide , polymeric biguanide compounds containing terminal amino groups, 4-phenylsemicarbazide, 4-phenyl-3-thiosemicarbazide, 1,2,3-triphenylguanidine and the like.

Solid aromatic amines containing secondary amino groups may include monoamines having one secondary amino group, and polyamines having two or more amino groups, at least one of which is a secondary amino group. may contain. From the viewpoint of improving the curing speed of the one-liquid epoxy resin composition and the mechanical properties of the cured product, the solid aromatic amine containing secondary amino groups (C-B1) has a number of primary amino groups. and tertiary amino groups in excess of the total number of solid aromatic amines. (C-B1) The solid aromatic amine having more secondary amino groups than the total number of primary and tertiary amino groups includes (C-B1′) a solid aromatic amine containing only secondary amino groups as amino groups. It preferably contains an aromatic amine (the number of secondary amino groups is 1, 2, or 3 or more, and the total number of primary and tertiary amino groups is 0).

(C-B1) The solid aromatic amine having more secondary amino groups than the total number of primary amino groups and tertiary amino groups is, for example, a solid aromatic amine having only one secondary amino group as an amino group. monoamine (equivalent to C-B1′), solid aromatic polyamine having only two or more secondary amino groups as amino groups (equivalent to C-B1′), one primary amino group and two secondary amino groups a solid aromatic polyamine having two secondary amino groups and one tertiary amino group; a solid aromatic polyamine having one primary amino group and three or more secondary amino groups; three or more and solid aromatic polyamines having one secondary amino group and one tertiary amino group.

Preferred examples of solid aromatic monoamines (corresponding to C-B1′) having only one secondary amino group as an amino group include N-phenyl-1-naphthylamine, octylated diphenylamine, 4,4′-bis(α ,α-dimethylbenzyl)diphenylamine, N-(p-tolyl)-1-naphthylamine, N-phenyl-3-biphenylamine, bis(3-biphenylyl)amine, 2-(3-biphenylyl)amino-9,9- Dimethylfluorene, bis(4-tert-butylphenyl)amine, 4-tert-butylphenylphenylamine, bis-α-methylbenzylphenothiazine, reaction product of diphenylamine and 2,4,4-trimethylpentene, diphenylamine, N- phenylbenzylamine, 3-methyldiphenylamine, 3,4-dimethyldiphenylamine, 4,4'-dimethyldiphenylamine, 3-methoxydiphenylamine, 10-methoxy-2,2'-iminostilbene, N-benzyl-2-naphthylamine, 1 , 2′-dinaphthylamine, 1,1′-dinaphthylamine and the like.

Preferred examples of solid aromatic polyamines (corresponding to C-B1′) having only two or more secondary amino groups as amino groups include 4-isopropylaminodiphenylamine, 2,6-bis[(2-hydroxyethyl) amino]toluene, 4-(2-octylamino)diphenylamine, N-(1,3-dimethylbutyl)-N'-phenyl-1,4-phenylenediamine, 2,2,4-trimethyl-1,2-dihydro Quinoline polymer, 1,3-diphenylguanidine, p-(p-toluenesulfonylamido)diphenylamine, N-phenyl-N'-(3-methacryloyloxy-2-hydroxypropyl)-p-phenylenediamine, bis(2- benzamidophenyl)disulfide, N,N'-diphenyl-1,4-phenylenediamine, 1,3-di-o-tolylguanidine, 1,5-diphenylcarbonohydrazide, N,N'-diphenylethylenediamine, 5-( acetoacetamido)-2-benzimidazolinone and the like.

(C-B1) Other examples of solid aromatic amines having more secondary amino groups than the total number of primary and tertiary amino groups include 1-(o-tolyl)biguanide and 1-phenylguanidine. , phenylbiguanide, polymeric biguanide compounds containing terminal amino groups, 4-phenylsemicarbazide, 4-phenyl-3-thiosemicarbazide, 1,2,3-triphenylguanidine and the like.

Solid aromatic amines containing secondary amino groups may include (C-B2) solid aromatic polyamines in which the number of secondary amino groups is less than or equal to the total number of primary and tertiary amino groups. For example, (C-B) a solid aromatic amine containing a secondary amino group is (C-B1) a solid aromatic amine in which the number of secondary amino groups is greater than the total number of primary and tertiary amino groups. and (C-B2) a solid aromatic polyamine in which the number of secondary amino groups is equal to or less than the total number of primary and tertiary amino groups. In this case, the curing agent [C] further contains a (CC) aliphatic cyclic polyamine described later. Alternatively, (C-B) a solid aromatic amine containing a secondary amino group, (C-B1) a solid aromatic amine having more secondary amino groups than the total number of primary amino groups and tertiary amino groups , and (C-B2) a solid aromatic polyamine in which the number of secondary amino groups is equal to or less than the total number of primary amino groups and tertiary amino groups. In this case, the curing agent [C] may or may not further contain a (CC) aliphatic cyclic polyamine described later.

(C-B2) The solid aromatic polyamine in which the number of secondary amino groups is equal to or less than the total number of primary amino groups and tertiary amino groups includes solid aromatic polyamines containing primary and secondary amino groups ( For example, solid aromatic polyamines having one primary amino group and one secondary amino group, solid aromatic polyamines having two primary amino groups and one secondary amino group, etc.), secondary amino groups and three solid aromatic polyamines containing primary amino groups (e.g., solid aromatic polyamines containing one secondary amino group and one tertiary amino group), primary amino groups, secondary amino groups, and tertiary amino groups; and solid aromatic polyamines comprising:

(C-B2) Preferable examples of solid aromatic polyamines having the number of secondary amino groups equal to or less than the total number of primary amino groups and tertiary amino groups include 4-aminodiphenylamine, 2,4-diaminodiphenylamine, 2 -aminodiphenylamine, 4-amino-4'-methoxydiphenylamine, 1-phenylbiguanide, isophthalic acid dihydrazide, terephthalic acid dihydrazide, 2,6-naphthoic acid dihydrazide, 4,4'-bisbenzenedihydrazide, 1,4-naphthoic acid dihydrazide, naphthalene-2,6-dicarbohydrazide, 3-hydroxy-2-naphthoic acid hydrazide and the like.

(CB) Solid aromatic amines containing secondary amino groups may be used singly or in combination of two or more. For example, (C-B1) a solid aromatic amine in which the number of secondary amino groups is greater than the total number of primary and tertiary amino groups, and (C-B2) a primary amino group in which the number of secondary amino groups is A solid aromatic polyamine whose number is equal to or less than the total number of tertiary amino groups may be used in combination. Alternatively, as the (C-B) solid aromatic amine containing a secondary amino group, two or more (C-B1) solid aromatic amines in which the number of secondary amino groups is greater than the total number of primary amino groups and tertiary amino groups Aromatic amines may be used in combination, and solid aromatic polyamines in which the number of two or more (C-B2) secondary amino groups is equal to or less than the total number of primary and tertiary amino groups. may be used.

(CB) The solid aromatic amine containing a secondary amino group may have a substituent such as halogen on the aromatic ring. By using a solid aromatic amine containing a (C—B) secondary amino group having a halogen substituent on the aromatic ring, it is possible to improve the viscosity stability of the one-component epoxy resin composition.

Commercially available examples of solid aromatic polyamines containing secondary amino groups include 1-(o-tolyl)biguanide (“Noxcellar BG” manufactured by Ouchi Shinko Kagaku Kogyo Co., Ltd., “Aradur 2844” manufactured by HUNTSMAN, manufactured by Thomas Swan). "Casamine OTB"), 4-isopropylaminodiphenylamine ("Noclac 810-NA" manufactured by Ouchi Shinko Chemical Industry Co., Ltd., "Antage 3C" manufactured by Kawaguchi Chemical Industry Co., Ltd.), 4-aminodiphenylamine (manufactured by Seiko Chemical Co., Ltd. "4-amino Diphenylamine”, LANXESS “4-ADPA”), 2,2,4-trimethyl-1,2-dihydroquinoline polymer (Ouchi Shinko Kagaku Kogyo Co., Ltd. “Nocrac 224 (224-S)”, Seiko Kagaku Co., Ltd. "Nonflex RD" and "Nonflex QS" manufactured by Ouchi Shinko Chemical Industry Co., Ltd.), N-phenyl-1-naphthylamine ("Nocrac PA" manufactured by Ouchi Shinko Chemical Industry Co., Ltd.), 1,3-diphenylguanidine (manufactured by Ouchi Shinko Chemical Industry Co., Ltd. " Noccellar D", Sanshin Chemical Industry Co., Ltd. "Sancellar D, DG"), 4,4'-bis (α, α-dimethylbenzyl) diphenylamine (manufactured by Ouchi Shinko Kagaku Kogyo Co., Ltd. "Nocrac CD", Seiko Kagaku "Nonflex DCD" manufactured by the company).

When the curing agent [C] is 100% by mass, the solid aromatic polyamine containing a secondary amino group is preferably 1 to 45% by mass, more preferably 2 to 40% by mass, from the viewpoint of increasing the impact strength of the cured product. %, more preferably 3 to 35 mass %, in the curing agent [C].

From the viewpoint of improving mechanical properties such as elongation and bending strength of the cured product, the curing agent [C] is optionally a solid aromatic solid containing a primary amino group but not containing a secondary amino group and having a melting point of 160° C. or less. May contain amines. Preferred examples of solid aromatic amines containing primary amino groups but not secondary amino groups having a melting point of 160° C. or less include 4,4′-methylenebis(2-ethyl-6-methylaniline), 2,2′- Diisopropyl-6,6'-dimethyl-4,4'-methylenedianiline, 2,2',6,6'-tetraisopropyl-4,4'-methylenedianiline, 4,4'-methylenebis(2,6- diethylaniline), 4,4′-methylenebis(3-chloro-2,6-diethylaniline), 1,3-phenylenediamine, 2,4-diaminotoluene, 2,6-diaminotoluene, 2,4,6- trimethyl-1,3-phenylenediamine, 3-aminobiphenyl, 3-amino-4-methoxybiphenyl, 2-aminofluorene, 2-amino-9-fluorenone, 2,7-diaminofluorene, 3-aminobenzophenone, 3, 4'-diaminodiphenylmethane, 3,3'-diaminodiphenylmethane, 3,4-diaminobenzophenone, 3,3'-diaminobenzophenone and the like.

(C-C) Aliphatic cyclic polyamine curing agent [C] contains (C-B) a solid aromatic amine containing a secondary amino group, (C-B1) the number of secondary amino groups is three When the number of solid aromatic amines larger than the total number of secondary amino groups is not included (that is, (C-B) as a solid aromatic amine containing secondary amino groups, the number of (C-B2) secondary amino groups is primary If it contains only solid aromatic polyamines with the total number of amino groups and tertiary amino groups or less), it further contains (CC) aliphatic cyclic polyamines. In addition, the curing agent [C] is (C-B) a solid aromatic amine containing secondary amino groups, and (C-B1) the number of secondary amino groups is greater than the total number of primary amino groups and tertiary amino groups. When it contains a large amount of solid aromatic amine, it may or may not further contain a (C—C) aliphatic cyclic polyamine.

The (C-C) aliphatic cyclic polyamine in the curing agent [C] accelerates the curing of the epoxy resin by the (C-A) liquid aromatic polyamine and (C-B) the solid aromatic amine containing a secondary amino group. have an effect. That is, the curing agent [C] can accelerate the curing of the one-liquid type epoxy resin composition and increase the curing speed by containing the aliphatic cyclic polyamine. Aliphatic cyclic polyamines may be aliphatic hydrocarbons having two or more amino groups as substituents on the ring structure (i.e., attached to the ring) and in the ring structure (i.e., It may also be a heterocyclic amine having two or more amino groups. It may also be a heterocyclic amine having one or more amino groups as substituents on the ring structure and one or more amino groups in the ring structure. Amino groups as substituents on the ring structure include primary amino groups and secondary amino groups, with primary amino groups being preferred. A secondary amino group is preferred as the amino group in the ring structure of the heterocyclic amine.

In the aliphatic cyclic polyamine used in the present invention, those in which nitrogen atoms and amino groups do not form complexes or salt structures are preferably selected. In the case of aliphatic cyclic polyamines having free amino groups that do not form complexes or salt structures, compared to aliphatic cyclic polyamines in which nitrogen atoms and amino groups form complexes or salt structures and are stabilized, one liquid The curing speed of the type epoxy resin composition can be increased.

In the ring structure of the aliphatic cyclic polyamine in the present invention, preferably, an element (such as a carbon atom) adjacent to an amino group (preferably a secondary amino group) in the ring structure and/or an amino group on the ring structure is bonded. All the substituents of the elements (such as carbon atoms) adjacent to the element (such as carbon atoms) are hydrogen atoms. When all of the above substituents are hydrogen atoms, there is no steric hindrance in reacting the amino group with the epoxy resin compared to the case where a substituent other than a hydrogen atom (for example, an alkyl group) is attached. The curing speed of the one-liquid type epoxy resin composition can be increased. When there are two or more amino groups in the ring structure, at least the substituents of the two elements adjacent to one amino group in the ring structure are all hydrogen atoms. It is preferred that all the substituents of the elements adjacent to the amino group are hydrogen atoms. When two or more amino groups are bonded to the ring structure as substituents, at least the substituents of two elements adjacent to one element to which the amino group is bonded are all hydrogen atoms. Although good, it is preferred that all the substituents of the elements adjacent to all the elements to which the amino group is attached are hydrogen atoms. More preferably, an element (such as a carbon atom) other than an amino group (preferably a secondary amino group) in the ring structure and/or an element (such as a carbon atom) to which the amino group on the ring structure is bonded ( carbon atoms, etc.) are all hydrogen atoms.

The aliphatic cyclic polyamine preferably has a boiling point of 140°C or higher, more preferably 145°C to 250°C. If the boiling point is 140° C. or higher, it is sufficiently higher than the temperature at which the reinforcing fiber is impregnated into the one-component epoxy resin composition in the manufacturing process of the fiber-reinforced composite material using the epoxy resin as the matrix resin. Volatilization of the cyclic polyamine component can be suppressed, and as a result, structural defects and reduction in strength of the fiber-reinforced composite material can be suppressed.

The aliphatic cyclic polyamine preferably has a melting point of 160° C. or lower, for example, 150° C. or lower, 140° C. or lower, 130° C. or lower, or 120° C. or lower. If the melting point is 160° C. or less, it can be easily dissolved in a liquid aromatic polyamine in a short time.

The aliphatic cyclic polyamine is preferably a compound having one, two or three ring structures from the viewpoint of reducing the viscosity of the one-liquid type epoxy resin composition.

The aliphatic cyclic polyamine preferably contains a primary amino group or a secondary amino group from the viewpoint of enhancing the heat resistance of the cured product. From the viewpoint of reactivity, the amino group in the ring structure preferably contains a secondary amino group, more preferably contains only a secondary amino group, and the amino group as a substituent includes a primary amino group. It is more preferable to include If a primary amino group or secondary amino group is contained, a tertiary amino group may be contained within a range that does not adversely affect physical properties such as heat resistance of the cured product.

Aliphatic cyclic polyamines containing a secondary amino group preferably have a piperazine skeleton, such as piperazine, 2-methylpiperazine, homopiperazine, trans-2,5-dimethylpiperazine, cis-2,6-dimethylpiperazine. , (S)-(+)-2-methylpiperazine, N-(2-aminoethyl)piperazine, 1-butylpiperazine, 1-methylpiperazine, 2-piperazinone and the like. Among them, piperazine is more preferable as the aliphatic cyclic polyamine because it has high reactivity and can shorten the curing time.

Other preferred examples of aliphatic cyclic polyamines containing secondary amino groups include 1,3-bis(aminomethyl)cyclohexane, dexrazoxane, 3-aminopyrrolidine, 3-(methylamino)pyrrolidine, 3-(ethylamino) pyrrolidine, (1S,6S)-2,8-diazabicyclo[4.3.0]nonane, 3-acetamidopyrrolidine, 4-aminopiperidine, 3-amino-2-piperidone, 3-(aminomethyl)piperidine, 2- Piperidinecarboxamide, 3-acetamidopiperidine, 4-amino-2,2,6,6-tetramethylpiperidine, 4,4'-bipiperidine, DL-α-amino-ε-caprolactam, 1,2,3,4-cyclobutane Tetracarboxylic acid diimide, trans-N,N'-dimethylcyclohexane-1,2-diamine, (1S,2S)-(+)-N,N'-dimethylcyclohexane-1,2-diamine, (1R,2R) -(-)-N,N'-dimethylcyclohexane-1,2-diamine, N-(3-aminopropyl)cyclohexylamine, N-(1-adamantyl)ethylenediamine, trans-N,N'-diacetylcyclohexane-1 ,2-diamine, 1-adamantylthiourea, (1S,2R)-N1-(tert-butoxycarbonyl)-1,2-cyclohexanediamine, (1R,2S)-N1-(tert-butoxycarbonyl)-1, 2-cyclohexanediamine, (1S,2S)-N1-(tert-butoxycarbonyl)-1,2-cyclohexanediamine, (1R,2R)-N1-(tert-butoxycarbonyl)-1,2-cyclohexanediamine, 1 ,3-dicyclohexylurea, 1,3-dicyclohexylthiourea, 1-cyclohexylguanidine, 1-cyclohexylbiguanide and the like.

When the curing agent [C] is 100% by mass, the aliphatic cyclic polyamine, if present, is preferably 0.5 to 15% by mass, more preferably 0.8 to 12% by mass, still more preferably 1 It is contained in the curing agent [C] in an amount of ∼10% by weight. When the aliphatic cyclic polyamine is 1% by mass or more, the curing speed of the one-component epoxy resin composition can be increased, and when it is 15% by mass or less, the heat resistance of the cured product is not impaired.

The curing agent [C] may optionally contain additional components such as borate compounds, titanate compounds, zirconate compounds, silane compounds, carboxylic acid compounds, phenol compounds, and halogen compounds within the range that does not impair the effects of the present invention. These additional components may be included in salt form with solid aromatic amines containing (CB) secondary amino groups.

The curing agent [C] may be in a liquid form obtained by dissolving a solid aromatic amine containing a secondary amino group and, if present, an aliphatic cyclic polyamine in a liquid aromatic polyamine. The aromatic polyamine may be in the form of a suspension in which the solid aromatic amine containing secondary amino groups and, if present, the aliphatic cyclic polyamine are present as solids. Curing agent [C] is preferably in liquid form. By dissolving other components in the liquid aromatic polyamine to make the curing agent [C] a liquid state, in the process of manufacturing a fiber-reinforced composite material using an epoxy resin as a matrix resin, the one-liquid epoxy resin composition is added to the fiber. can be impregnated quickly.

The total amount of the curing agent [C] contained in the epoxy resin composition is an amount suitable for curing all the epoxy resins blended in the epoxy resin composition, and varies depending on the type of epoxy resin and curing agent used. adjusted accordingly. Specifically, the ratio of the number of epoxy groups contained in the epoxy resin in the epoxy resin composition to the number of active hydrogens contained in the curing agent [C] should be 0.7 to 1.3, more preferably 0.3. 8 to 1.2, more preferably 0.9 to 1.1. If the ratio of the number of epoxy groups contained in the epoxy resin in the epoxy resin composition to the number of active hydrogens contained in the curing agent [C] is 0.7 to 1.3, appropriate epoxy groups and active hydrogens , the cured resin obtained has a sufficient crosslink density, and desired heat resistance and mechanical properties such as elastic modulus and fracture toughness can be obtained.

1-4. Resin particle component [D]
The epoxy resin composition of the present invention contains a resin particle component [D]. In the present invention, the term "particulate" means that the epoxy resin composition is dispersed without being dissolved, and even in the resin cured product after the epoxy resin composition is cured, the island component is dispersed and dispersed. Constitute.
The resin particle component [D] improves the fracture toughness and impact resistance of the cured resin and fiber-reinforced composite material.
As the resin particle component [D], thermoplastic resin particles, thermosetting resin particles, rubber particles and the like can be used. It is particularly preferred to use rubber particles. Rubber particles include silicone rubber, butadiene rubber, styrene-butadiene rubber, and methyl methacrylate-butadiene-styrene rubber.
Commercially available rubber particles used as the resin particle component [D] include MX-153 (a bisphenol A type epoxy resin in which 33% by mass of butadiene rubber is monodispersed, manufactured by Kaneka Corporation), MX- 257 (37% by mass of butadiene rubber dispersed in bisphenol A type epoxy resin, manufactured by Kaneka Corporation), MX-154 (bisphenol A type epoxy resin with 40% by mass of butadiene rubber Dispersed material, manufactured by Kaneka Corporation), MX-960 (Bisphenol A epoxy resin with 25% by mass of silicone rubber dispersed in a single dispersion, manufactured by Kaneka Corporation), MX-136 (Bisphenol F 25% by mass of butadiene rubber monodispersed in type epoxy resin, manufactured by Kaneka Corporation), MX-965 (bisphenol F type epoxy resin with 25% by mass of silicone rubber monodispersed. , manufactured by Kaneka Co., Ltd.), MX-217 (a phenol novolak type epoxy resin in which 25% by mass of butadiene rubber is dispersed in a single dispersion, manufactured by Kaneka Co., Ltd.), MX-227M75 (bisphenol A novolac type epoxy resin in which 25% by mass of styrene-butadiene rubber is monodispersed, manufactured by Kaneka Corporation), MX-334M75 (brominated epoxy resin, 25% by mass of styrene-butadiene rubber is monodispersed, stock Kaneka Corporation), MX-416 (monodispersion of 25% by mass of butadiene rubber in a tetrafunctional glycidylamine type epoxy resin, manufactured by Kaneka Corporation), MX-451 (trifunctional glycidylamine type epoxy 25% by mass of styrene-butadiene rubber is uniformly dispersed in resin, manufactured by Kaneka Corporation), MX-150 (difunctional bisphenol A type epoxy resin, 40% by mass of butadiene rubber is uniformly dispersed. (manufactured by Kaneka Corporation).

The average particle size of the resin particle component [D] is preferably 1 µm or less, more preferably 0.5 µm or less, and even more preferably 0.3 µm or less. Although the lower limit of the average particle size is not particularly limited, it is preferably 0.03 μm or more, more preferably 0.05 μm or more, and even more preferably 0.08 μm or more. When the average particle diameter is 1 μm or less, in the step of impregnating the reinforcing fiber base material with the one-liquid epoxy resin composition, the resin particle component [D] is not filtered on the surface of the reinforcing fiber base material, and the inside of the reinforcing fiber bundle is impregnation becomes easier. As a result, impregnation failure of the resin can be prevented, and a fiber-reinforced composite material having excellent physical properties can be obtained. The average particle diameter referred to here is obtained by observing the particle cross section with a scanning electron microscope or a transmission electron microscope and measuring the diameter of at least 50 particles, for example, as in [Evaluation method] (3) below. The average particle diameter can be obtained by averaging the particle diameters of the resin particles. In the above observation, when the particles are not perfectly circular, that is, when the particles are elliptical, the maximum diameter of the particles is taken as the particle diameter of the particles.
The content of the resin particle component [D] in the epoxy resin composition of the present invention is preferably 0.1 to 50% by mass, more preferably 0.5 to 20% by mass, of the total amount of the epoxy resin composition. More preferably, it is still more preferably 1 to 15% by mass. When it is 0.1% by mass or more, the fracture toughness and impact resistance of the cured resin and fiber composite material are sufficiently improved.
The resin particle component [D] can also be used as a masterbatch dispersed in an epoxy resin at a high concentration. In this case, it becomes easy to highly disperse the resin particle component in the epoxy resin composition.

1-5. Other Optional Components The epoxy resin composition of the present invention essentially comprises the above epoxy resin [A], epoxy resin [B], curing agent [C] and resin particle component [D]. and epoxy resins other than [B], thermosetting resins other than epoxy resins, thermoplastic resins other than the resin particle component [D], curing agents other than the curing agent [C], and other additives. . In the case of a two-component epoxy resin composition, the main liquid may contain an epoxy resin other than the epoxy resins [A] and [B], or a thermosetting resin other than the epoxy resin, and the curing agent liquid may contain a curing agent [C ], and the main liquid and the curing agent liquid may contain a thermoplastic resin other than the resin particle component [D] and other additives.
As epoxy resins other than epoxy resins [A] and [B], conventionally known epoxy resins can be used, and examples thereof include monofunctional epoxy resins. Among these, an epoxy resin containing an aromatic group is preferred, and an epoxy resin containing either a glycidylamine structure or a glycidyl ether structure is preferred. Alicyclic epoxy resins can also be suitably used. In addition, these epoxy resins may optionally have a non-reactive substituent on the aromatic ring structure or the like. Examples of non-reactive substituents include alkyl groups such as methyl group, ethyl group and isopropyl group, aromatic groups such as phenyl group, alkoxyl groups, aralkyl groups and halogen groups such as chlorine and bromine.
Examples of thermosetting resins other than epoxy resins include vinyl ester resins, benzoxazine resins, bismaleimide resins, and bismaleimide-triazine resins.
The epoxy resin composition of the present invention may contain a curing agent other than curing agent [C].
Examples of curing agents other than the curing agent [C] include aliphatic polyamines, various isomers of aromatic amine curing agents, aminobenzoic acid esters, and acid anhydrides (however, the above curing agent [C ] components).

Examples of aliphatic polyamines include 4,4'-diaminodicyclohexylmethane, isophoronediamine, m-xylylenediamine and the like.
Aromatic polyamines are preferable because they are excellent in heat resistance and various mechanical properties. Examples of aromatic polyamines include diaminodiphenyl sulfones, diaminodiphenylmethanes, diaminodiphenyl ethers and toluenediamines. Aromatic diamine compounds such as 4,4'-diaminodiphenylsulfone, 3,3'-diaminodiphenylsulfone, 4,4'-diaminodiphenylmethane and their derivatives having non-reactive substituents are cured products having high heat resistance. can be obtained, it is particularly preferable. Furthermore, 3,3′-diaminodiphenylsulfone is more preferable because the heat resistance and elastic modulus of the cured resin obtained are high. Examples of non-reactive substituents include alkyl groups such as methyl group, ethyl group and isopropyl group, aromatic groups such as phenyl group, alkoxyl groups, aralkyl groups and halogen groups such as chlorine and bromine.

Preferred aminobenzoic acid esters include trimethylene glycol di-p-aminobenzoate and neopentyl glycol di-p-aminobenzoate. Composite materials cured with these curing agents have high tensile elongation.
Acid anhydrides include 1,2,3,6-tetrahydrophthalic anhydride, hexahydrophthalic anhydride, and 4-methylhexahydrophthalic anhydride.
When these curing agents are used, the usable life of the uncured resin composition is long, and a cured product having relatively well-balanced electrical, chemical and mechanical properties can be obtained. Therefore, the curing agent is appropriately selected depending on the application of the composite material.
The total amount of the curing agent contained in the epoxy resin composition is an amount suitable for curing all the epoxy resins contained in the epoxy resin composition, and may be appropriately adjusted depending on the type of epoxy resin and curing agent used. adjusted. Specifically, the ratio of the number of epoxy groups contained in the epoxy resin in the epoxy resin composition to the number of active hydrogens contained in the amine curing agent is 0.7 to 1.3, more preferably 0.8. to 1.2, more preferably 0.9 to 1.1. If the ratio of the number of epoxy groups contained in the epoxy resin in the epoxy resin composition to the number of active hydrogens contained in the amine curing agent is 0.7 to 1.3, the moles of appropriate epoxy groups and active hydrogens Due to the balance, the cured resin obtained has a sufficient crosslink density, and desired heat resistance, and mechanical properties such as elastic modulus and fracture toughness can be obtained.
The epoxy resin composition of the present invention may contain a thermoplastic resin as a component to be dissolved in the epoxy resin composition in addition to the resin particle component [D]. The thermoplastic resin improves the fracture toughness and impact resistance of the resulting fiber-reinforced composite material. Such a thermoplastic resin may be dissolved in the one-component epoxy resin composition during the curing process of the epoxy resin composition.
Specific examples of thermoplastic resins include polyethersulfone, polysulfone, polyetherimide, polycarbonate and the like. These may be used alone or in combination of two or more. The thermoplastic resin contained in the epoxy resin composition is particularly preferably polyethersulfone or polysulfone having a weight average molecular weight (Mw) measured by gel permeation chromatography in the range of 8,000 to 100,000. If the weight-average molecular weight (Mw) is 8000 or more, the resulting FRP will have sufficient impact resistance, and if it is 100000 or less, the one-liquid type epoxy resin composition will exhibit good handleability without markedly increasing viscosity. you get something. The epoxy resin-soluble thermoplastic resin preferably has a uniform molecular weight distribution. In particular, the polydispersity (Mw/Mn), which is the ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn), is preferably in the range of 1 to 10, more preferably in the range of 1.1 to 5. more preferred.
The thermoplastic resin preferably has a reactive group reactive with the epoxy resin or a functional group forming a hydrogen bond. Such thermoplastic resins can improve the dissolution stability during the curing process of epoxy resins. In addition, fracture toughness, chemical resistance, heat resistance, and resistance to moist heat can be imparted to the fiber-reinforced composite material obtained after curing.

A hydroxyl group, a carboxylic acid group, an imino group, an amino group and the like are preferable as the reactive group having reactivity with the epoxy resin. The use of hydroxyl-terminated polyethersulfone is more preferable because the resulting fiber-reinforced composite material has particularly excellent impact resistance, fracture toughness and solvent resistance.
The content of the thermoplastic resin contained in the epoxy resin composition is appropriately adjusted according to the viscosity. From the viewpoint of impregnation into the fiber-reinforced base material, the amount is preferably 0.1 to 10 parts by mass, more preferably 0.5 to 5 parts by mass, with respect to 100 parts by mass of the epoxy resin contained in the epoxy resin composition. When the content is 0.1 part by mass or more, the resulting fiber-reinforced composite material exhibits sufficient fracture toughness and impact resistance. If the content of the thermoplastic resin is 10 parts by mass or less, the viscosity of the one-liquid type epoxy resin composition does not significantly increase, and the impregnation of the fiber-reinforced base material becomes easy, resulting in the properties of the fiber-reinforced composite material. improves.
The thermoplastic resin preferably contains a reactive aromatic oligomer having amine end groups (hereinafter also simply referred to as "aromatic oligomer").
The epoxy resin composition has a high molecular weight due to a curing reaction between the epoxy resin and the curing agent during heat curing. The expansion of the two-phase region due to the increase in the molecular weight causes the aromatic oligomer dissolved in the epoxy resin composition to undergo reaction-induced phase separation. Due to this phase separation, a two-phase resin structure in which the cured epoxy resin and the aromatic oligomer are co-continuous is formed in the matrix resin. Also, since aromatic oligomers have amine end groups, they also react with epoxy resins. Since each phase in this co-continuous two-phase structure is strongly bonded to each other, solvent resistance is also improved.

This co-continuous structure absorbs external impact on the fiber-reinforced composite material and suppresses crack propagation. As a result, fiber reinforced composites made with epoxy resin compositions containing reactive aromatic oligomers with amine end groups have high impact resistance and fracture toughness.
As the aromatic oligomer, known polysulfones having amine end groups and polyether sulfones having amine end groups can be used. Preferably, the amine end groups are primary amine (--NH ₂ ) end groups.
The aromatic oligomer blended in the epoxy resin composition preferably has a weight average molecular weight of 8,000 to 40,000 as measured by gel permeation chromatography. When the weight average molecular weight is 8000 or more, the effect of improving the toughness of the matrix resin is high. Moreover, when the weight average molecular weight is 40,000 or less, the viscosity of the resin composition does not become too high, and processing advantages such as the impregnation of the reinforcing fiber base material with the resin composition being facilitated can be obtained.
As the aromatic oligomer, commercially available products such as "Virantage DAMS VW-30500 RP (registered trademark)" (manufactured by Solvay Specialty Polymers) can be preferably used.
The form of the thermoplastic resin before being mixed with the epoxy resin composition is not particularly limited, but it is preferably particulate. The particulate thermoplastic resin can be uniformly blended and dissolved in the resin composition.

The epoxy resin composition of the present invention may contain conductive particles, flame retardants, inorganic fillers, and internal release agents as other additives.
Conductive particles include conductive polymer particles such as polyacetylene particles, polyaniline particles, polypyrrole particles, polythiophene particles, polyisothianaphthene particles and polyethylenedioxythiophene particles; carbon particles; carbon fiber particles; Particles in which a core material made of a material is coated with a conductive substance are exemplified.
Examples of flame retardants include phosphorus-based flame retardants. The phosphorus-based flame retardant is not particularly limited as long as it contains a phosphorus atom in the molecule. be done.
Examples of inorganic fillers include aluminum borate, calcium carbonate, silicon carbonate, silicon nitride, potassium titanate, basic magnesium sulfate, zinc oxide, graphite, calcium sulfate, magnesium borate, magnesium oxide, and silicate minerals. is mentioned. In particular, it is preferable to use silicate minerals. Commercially available silicate minerals include THIXOTROPIC AGENT DT 5039 (manufactured by Huntsman Japan KK).
Examples of internal release agents include metal soaps, vegetable waxes such as polyethylene wax and carnauba wax, fatty acid ester release agents, silicone oils, animal waxes, and fluorine-based nonionic surfactants. The content of these internal release agents is preferably 0.1 to 5 parts by mass, more preferably 0.2 to 2 parts by mass, per 100 parts by mass of the epoxy resin. Within this range, the release effect from the mold is favorably exhibited.
Commercially available internal release agents include "MOLD WIZ (registered trademark)" INT1846 (manufactured by AXEL PLASTICS RESEARCH LABORATORIES INC.), Licowax S, Licowax P, Licowax OP, Licowax PE190, Licowax PED (manufactured by Clariant Japan), Stearyl stearate (SL-900A; manufactured by Riken Vitamin Co., Ltd.).

1-6. Manufacturing method of epoxy resin composition 1-6-1. Method for Producing Main Component Liquid The main component liquid in the two-component epoxy resin composition of the present invention can be produced by mixing the epoxy resin [A] and the epoxy resin [B]. If necessary, the resin particle component [D] and/or other optional components, such as epoxy resins other than epoxy resins [A] and [B], thermosetting resins other than epoxy resins, resin particle component [ D] may be mixed with a thermoplastic resin or the like. The mixing order and mixing means are not limited.
The state of the main liquid may be a one-liquid state in which each component is uniformly mixed, or a slurry state in which a part of the components are dispersed as solids.
The method for producing the main component liquid is not particularly limited, and any conventionally known method may be used. As the mixing temperature, a range of 40 to 200° C. can be exemplified. If the temperature exceeds 200° C., the self-polymerization reaction of the epoxy resin partially progresses, and the impregnating properties of the reinforcing fiber base material are lowered, and the physical properties of the cured product produced using the resulting base liquid are lowered. sometimes. If the temperature is less than 40°C, the viscosity of the main component liquid is high, and mixing may be substantially difficult. It is preferably in the range of 50 to 100°C, more preferably in the range of 50 to 90°C.
A conventionally known machine can be used as the mixing machine. Specific examples include roll mills, planetary mixers, kneaders, extruders, Banbury mixers, mixing vessels equipped with stirring blades, and horizontal mixing tanks. Mixing of each component can be performed in air or under an inert gas atmosphere. When mixing is performed in air, an atmosphere in which temperature and humidity are controlled is preferable. Although not particularly limited, it is preferable to mix in a low-humidity atmosphere with a relative humidity of 50% RH or less, for example.

1-6-2. Method for producing curing agent liquid The method for producing the curing agent [C], which is an essential component of the curing agent liquid, is, for example, in the case of a liquid curing agent, (CA) liquid aromatic polyamine, (CB ) dissolving a solid aromatic amine containing a secondary amino group to obtain a curing agent [C]; The step of dissolving the (CC) aliphatic cyclic polyamine is further included if it does not contain a solid aromatic amine having a number of primary and tertiary amino groups greater than the total number of primary and tertiary amino groups. In the method for producing the liquid curing agent [C], (C-B) a solid aromatic amine containing a secondary amino group, (C-B1) the number of secondary amino groups is a primary amino group and a tertiary amino group. group, in addition to the step of dissolving (C-B) the solid aromatic amine containing secondary amino groups in (C-A) the liquid aromatic polyamine, -C) A step of dissolving the aliphatic cyclic polyamine may be further included. There are no particular restrictions on the dissolution means, and for example, after mixing the raw materials, they may be heated and dissolved using a heating device such as an oven or a heated tank. The conditions when using an oven include, for example, a temperature of 80 to 120° C., 90 to 110° C., or 95 to 105° C., for a time of 20 to 90 minutes, 30 to 60 minutes, or 40 to 50 minutes, May be heated. The heating temperature and heating time can be appropriately adjusted according to the heating apparatus used and the scale of the raw material.
The method for producing the curing agent liquid comprises, if necessary, the curing agent [C], the resin particle component [D] and/or other optional components, such as thermoplastic resins other than the resin particle component [D] and other A step of mixing with a curing agent or the like may be further included. The means and conditions for mixing are not particularly limited, and can be appropriately adjusted according to the type of other curing agents.

1-6-3. Method for producing one-liquid type epoxy resin composition The one-liquid type epoxy resin composition of the present invention can be produced by mixing a main liquid and a curing agent liquid. At least one of the main agent liquid and the curing agent liquid contains the resin particle component [D]. Whether the resin particle component [D] is contained in the main liquid or the curing agent liquid, it does not affect the properties of the one-liquid type epoxy resin composition and its cured product. If necessary, epoxy resins other than epoxy resins [A] and [B], thermosetting resins other than epoxy resins, thermoplastic resins other than resin particle component [D], curing agents other than curing agent [C], etc. and may be further mixed. Moreover, the order of mixing these is not asked.
The resulting one-liquid type epoxy resin composition is in a slurry state in which some components including the resin particle component [D] are dispersed as solids.
The method of mixing the main component liquid and the curing agent liquid is not particularly limited, and any conventionally known method may be used. As the mixing temperature, a range of 40 to 120°C can be exemplified. If the temperature is 120° C. or less, the curing reaction can be prevented from partially progressing and the impregnating properties of the reinforcing fiber base material can be prevented from deteriorating, and the resulting one-liquid epoxy resin composition is also excellent in storage stability. When the temperature is 40° C. or higher, the one-liquid epoxy resin composition has an appropriate viscosity, which facilitates mixing of each component. It is preferably in the range of 50 to 100°C, more preferably in the range of 50 to 90°C.
A conventionally known machine can be used as the mixing machine. Specific examples include roll mills, planetary mixers, kneaders, extruders, Banbury mixers, mixing vessels equipped with stirring blades, and horizontal mixing tanks. Mixing of each component can be performed in air or under an inert gas atmosphere. When mixing is performed in air, an atmosphere in which temperature and humidity are controlled is preferable.

2. Fiber Reinforced Composite Material A fiber reinforced composite material can be obtained by combining a fiber reinforced substrate and the one-liquid type epoxy resin composition of the present invention and curing the composition.
The reinforcing fiber base material used in the present invention is not particularly limited, and examples thereof include carbon fiber, glass fiber, aramid fiber, silicon carbide fiber, polyester fiber, ceramic fiber, alumina fiber, boron fiber, metal fiber, mineral fiber, and rock. Fibers and slag fibers and the like.
Among these reinforcing fibers, carbon fibers, glass fibers, and aramid fibers are preferred. Carbon fiber is more preferable because it has good specific strength and specific modulus, and provides a lightweight and high-strength fiber-reinforced composite material. Polyacrylonitrile (PAN)-based carbon fibers are particularly preferred because of their excellent tensile strength.
When PAN-based carbon fiber is used as the reinforcing fiber, its tensile modulus is preferably 100 to 600 GPa, more preferably 200 to 500 GPa, and particularly preferably 230 to 450 GPa. Also, the tensile strength is preferably 2000 to 10000 MPa, more preferably 3000 to 8000 MPa. The diameter of the carbon fiber is preferably 4-20 μm, more preferably 5-10 μm. By using such carbon fibers, the mechanical properties of the resulting fiber-reinforced composite material can be improved. In the present invention, it is preferable that the reinforcing fibers are treated with a sizing agent. A bundle is preferred, an adhesion amount of 0.05 to 3.0 mass % is more preferred, and an adhesion amount of 0.1 to 2.0 mass % is particularly preferred. The greater the amount of sizing agent adhered, the stronger the adhesion between the reinforcing fibers and the matrix resin. On the other hand, when the adhesion amount is small, the obtained composite material tends to have excellent interlaminar toughness.

It is preferable to form the reinforcing fiber into a sheet for use. Examples of reinforcing fiber sheets include sheets in which a large number of reinforcing fibers are aligned in one direction, bidirectional woven fabrics such as plain weaves and twill weaves, multiaxial woven fabrics, nonwoven fabrics, mats, knits, braids, and paper made from reinforced fibers. can be mentioned. Among these, it is preferable to use a unidirectional aligning sheet, a bidirectional woven fabric, or a multiaxial woven fabric base material in which reinforcing fibers are formed into a sheet form as continuous fibers, since a fiber-reinforced composite material with more excellent mechanical properties can be obtained. The bidirectional woven fabric or multiaxial woven fabric base material may be obtained by laminating and stitching a plurality of unidirectional aligning sheets. In this case, in order to improve the post-impact compressive strength CAI of the fiber-reinforced composite material, a thermoplastic resin nonwoven fabric layer may be arranged on one side of the unidirectionally arranged sheet and then laminated to form a woven fabric. Non-woven fabric layers of thermoplastic resin include, for example, polyamide resin fibers, polyester resin fibers, polyethersulfone resin fibers, polysulfone resin fibers, polyetherimide resin fibers, polycarbonate resin fibers, and resin mixtures thereof. . The basis weight and the number of layers of the unidirectional alignment sheet can be appropriately set according to the use of the fiber-reinforced composite material. For example, the basis weight of the unidirectional alignment sheet may be 100 to 300 g/m ² , preferably 150 to 250 g/m ² . The thickness of one layer of the sheet-shaped reinforcing fiber base material is preferably 0.01 to 3 mm, more preferably 0.1 to 1.5 mm.
The method for compounding the fiber-reinforced base material and the one-component epoxy resin composition is not particularly limited, and the fiber-reinforced base material and the one-component epoxy resin composition may be combined in advance and then molded. For example, the resin transfer molding method (RTM method), the hand lay-up method, the filament winding method, the pultrusion method, and the like may be used to form a composite during molding.
A fiber-reinforced composite material can be obtained by combining a fiber-reinforced base material and the one-liquid type epoxy resin composition of the present invention, followed by curing by heating under specific conditions. Examples of methods for producing a fiber-reinforced composite material using the epoxy resin composition of the present invention include known molding methods such as the RTM method, autoclave molding method, and press molding method. The epoxy resin composition of the present invention is particularly suitable for the RTM method.

The RTM method is a preferable molding method from the viewpoint of efficiently obtaining a fiber-reinforced composite material having a complicated shape. Here, the RTM method means a method for obtaining a fiber-reinforced composite material by impregnating a fiber-reinforced base material placed in a mold with a liquid epoxy resin composition and curing the composition.
In the present invention, the mold used in the RTM method may be a closed mold made of a rigid material, or it is possible to use an open mold made of a rigid material and a flexible film (bag). In the latter case, the fiber reinforced substrate can be placed between an open mold of rigid material and the flexible film. As rigid materials, various existing materials such as metals such as steel and aluminum, fiber reinforced plastics (FRP), wood, and gypsum are used. Polyamide, polyimide, polyester, fluororesin, silicone resin, or the like is used as the material of the flexible film.
In the RTM method, when a closed mold made of a rigid material is used, the mold is clamped under pressure, and the one-liquid epoxy resin composition is usually injected under pressure. At this time, a suction port may be provided separately from the injection port and connected to a vacuum pump for suction. It is also possible to apply suction and inject the epoxy resin composition only at atmospheric pressure without using special pressurizing means. This method can be preferably used because a large-sized member can be manufactured by providing a plurality of suction ports.
In the RTM method, when an open mold made of a rigid material and a flexible film are used, suction may be performed to inject the one-liquid epoxy resin composition only under atmospheric pressure without using special pressurizing means. Use of a resin diffusion medium is effective in achieving good impregnation by injection only at atmospheric pressure. Furthermore, it is preferable to apply a gel coat to the surface of the rigid material prior to placing the fiber-reinforced substrate.
In the RTM method, a fiber-reinforced base material is impregnated with a one-component epoxy resin composition, and then heat-cured. The mold temperature during heat curing is usually selected to be higher than the mold temperature during injection of the one-liquid type epoxy resin composition. The mold temperature during heat curing is preferably 80 to 200°C. The heat curing time is preferably 1 minute to 20 hours. After heat curing is completed, the fiber-reinforced composite material is taken out by demolding. The resulting fiber-reinforced composite material may then be heated at a higher temperature for post-curing. The post-curing temperature is preferably 150 to 200° C., and the time is preferably 1 minute to 4 hours.

The impregnation pressure when impregnating the fiber-reinforced base material with the epoxy resin composition by the RTM method is appropriately determined in consideration of the viscosity and resin flow of the resin composition.
A specific impregnation pressure is 0.001 to 10 (MPa), preferably 0.01 to 1 (MPa). When obtaining a fiber-reinforced composite material using the RTM method, the viscosity of the one-liquid type epoxy resin composition is particularly preferably 1 to 200 mPa·s at 100°C.

EXAMPLES The present invention will be described in more detail with reference to examples below, but the present invention is not limited to the examples. Components and test methods used in Examples and Comparative Examples are described below.
〔component〕
(epoxy resin) (identified by constituent monomers)
epoxy resin [A]
Tetraglycidyl-4,4′-diaminodiphenylmethane (Araldite MY721 (product name) manufactured by Huntsman, hereinafter abbreviated as “4,4′-TGDDM”) epoxy equivalent: 112 g/eq, viscosity (50° C.): 4. 1 Pa.s
・Tetraglycidyl-3,4′-diaminodiphenyl ether (synthesized by the method of Synthesis Example 1, hereinafter abbreviated as “3,4′-TGDDE”) epoxy equivalent: 112 g/eq, viscosity (50° C.): 7.0 Pa・s
epoxy resin [B]
・ N,N-diglycidyl-o-toluidine (GOT (product name) manufactured by Nippon Kayaku Co., Ltd., hereinafter abbreviated as “GOT”) epoxy equivalent: 135 g / eq
・ N,N-diglycidylaniline (GAN (product name) manufactured by Nippon Kayaku Co., Ltd., hereinafter abbreviated as “GAN”) epoxy equivalent: 125 g / eq
1,6-bis(glycidyloxy)naphthalene (HP-4032SS (product name) manufactured by DIC, hereinafter abbreviated as “1,6-DON”) epoxy equivalent: 142 g/eq
・ Triglycidyl-p-aminophenol (Araldite MY0510 (product name) manufactured by Huntsman, hereinafter abbreviated as “TG-pAP”) epoxy equivalent: 96 g / eq
・ Triglycidyl-m-aminophenol (Araldite MY0600 (product name) manufactured by Huntsman, hereinafter abbreviated as “TG-mAP”) epoxy equivalent: 98 g / eq
・ 1,3,5-triglycidyl isocyanurate (TEPIC-S (product name) manufactured by Nissan Chemical Co., Ltd., hereinafter abbreviated as “TEPIC”) epoxy equivalent: 100 g / eq

(curing agent)
Curing agent [C]
HR-436: Diethyltoluenediamine (Ethacure 100 Plus (product name) manufactured by Albemarle) 34.6% by mass, dimethylthiotoluenediamine 41.6% by mass, 4,4′-methylenebis(2-ethyl-6-methyl) Aniline) (Cure Hard MED-J (product name) manufactured by Kumiai Chemical Industry Co., Ltd.) 1-(o-tolyl) biguanide (Noxeller BG (product name) manufactured by Ouchi Shinko Chemical Industry Co., Ltd.) in a mixture of 19.8% by mass ) is dissolved at 4.0% ・HR-499: Diethyltoluenediamine (Ethacure 100 Plus (product name) manufactured by Albemarle)) 60.0% by mass, 4,4'-methylenebis(2-ethyl-6-methyl Aniline) (Cure Hard MED-J (product name) manufactured by Kumiai Chemical Industry Co., Ltd.) 33.5% by mass, 4-aminodiphenylamine (manufactured by Seiko Chemical Co., Ltd.) 5.3% by mass, anhydrous piperazine (manufactured by Tosoh Corporation) 1 Curing agent dissolved to .1% by mass HR-571: Diethyltoluenediamine (Etacure 100 Plus (product name) manufactured by Albemarle)) 85.7% by mass and 2,2,4-trimethyl-1,2 - Dihydroquinoline polymer (Nonflex RD (product name) manufactured by Seiko Kagaku Co., Ltd.) 14.3% by mass of curing agent dissolved HR-659: 83.1% by mass of diethyltoluene diamine 2, 2, 4-trimethyl-1,2-dihydroquinoline polymer (Nonflex RD (product name) manufactured by Seiko Chemical Co., Ltd.) 14.0% by mass, N-phenyl-1-naphthylamine (Nocrac PA manufactured by Ouchi Shinko Chemical Industry Co., Ltd. Name)) Curing agent dissolved so as to be 2.9% by mass

(Other curing agents)
· 4,4'-diamino-3,3'-diisopropyl-5,5'-dimethyldiphenylmethane (Lonzacure M-MIPA (product name) manufactured by Lonza, hereinafter abbreviated as "M-MIPA") Active hydrogen equivalent: 78 g /eq
・ 2,2,4-trimethyl-1,2-dihydroquinoline polymer (Nonflex RD (product name) manufactured by Seiko Chemical Co., Ltd.)
・ Anhydrous piperazine (manufactured by Tosoh Corporation)
・Diethyltoluene diamine (Etacure 100 Plus (product name) manufactured by Albemarle)
(Resin particle component)
・ MX-416 (Kaneka Corporation MX-416 (product name), a masterbatch in which a particulate butadiene rubber component is dispersed in a glycidylamine-type tetrafunctional epoxy resin to a concentration of 25% by mass) (in the product Glycidylamine type tetrafunctional epoxy resin corresponds to epoxy resin [A] of the present invention) Average particle size of resin particles: 0.11 μm
・ MX-150 (MX-150 (product name) manufactured by Kaneka Corporation, a masterbatch in which a particulate butadiene rubber component is dispersed in a bisphenol A type bifunctional epoxy resin to a concentration of 40% by mass) (in the product Bisphenol A type bifunctional epoxy resin corresponds to the epoxy resin [B] of the present invention) Average particle size of resin particles: 0.11 μm

(carbon fiber strand)
・ Carbon fiber 1: "Tenax (registered trademark)" IMS65 E23 830tex (polyacrylonitrile-based carbon fiber strand, tensile strength 5.8 GPa, tensile modulus 290 GPa, sizing agent adhesion amount 1.2% by mass, single yarn diameter 5.0 μm , manufactured by Teijin Limited)
(Thermoplastic resin non-woven fabric)
・ Nonwoven fabric 1: Nonwoven fabric with a fiber basis weight of 5 g/m ² produced by a spunbond method using polyamide 12 resin (carbon fiber multilayer fabric)
・Carbon fiber multiaxial fabric 1: Carbon fiber 1 aligned in one direction is made into a sheet of 190 g / m ² per layer, and nonwoven fabric 1 is arranged on one side, (+45 / V / 90 / V / -45 /V/0/V) and stitched together (total carbon fiber basis weight of woven fabric substrate: 760 g/m ² , thickness per single layer during vacuum compression: 0.19 mm).
・Carbon fiber multiaxial fabric 2: Carbon fiber 1 aligned in one direction is made into a sheet of 190 g / m ² per layer, and nonwoven fabric 1 is arranged on one side, (-45 / V / 90 / V / +45 /V/0/V) and stitched together (total carbon fiber basis weight of woven fabric substrate: 760 g/m ² , thickness per single layer during vacuum compression: 0.19 mm).
V indicates the nonwoven fabric 1 here.

(Synthesis example of epoxy resin [A])
[Synthesis Example 1] Synthesis of 3,4'-TGDDE A four-necked flask equipped with a thermometer, a dropping funnel, a cooling tube and a stirrer was charged with 1110.2 g (12.0 mol) of epichlorohydrin and purged with nitrogen. The temperature was raised to 70° C. while continuing, and 200.2 g (1.0 mol) of 3,4′-diaminodiphenyl ether dissolved in 1000 g of ethanol was added dropwise over 4 hours. After further stirring for 6 hours, the addition reaction was completed to give N,N,N',N'-tetrakis(2-hydroxy-3-chloropropyl)-3,4'-diaminodiphenyl ether. Subsequently, after the temperature in the flask was lowered to 25° C., 500.0 g (6.0 mol) of 48% NaOH aqueous solution was added dropwise over 2 hours, and the mixture was further stirred for 1 hour. After completion of the cyclization reaction, ethanol was distilled off, extraction was performed with 400 g of toluene, and washing was performed twice with 5% saline. When toluene and epichlorohydrin were removed from the organic layer under reduced pressure, 361.7 g (85.2% yield) of brown viscous liquid was obtained. The purity of 3,4'-TGDDE, which is the main product, was 84% (HPLC area %).

[Evaluation method]
(1) Properties of Resin Composition (1-1) Preparation of Epoxy Resin Composition Epoxy resin [A], epoxy resin [B], and resin particle component "D" are weighed in proportions shown in Table 1 and stirred. The mixture was mixed at 80° C. for 60 minutes using a machine to prepare a main component liquid in which the resin particle component “D” was dispersed in the liquid epoxy resin mixture. Each component of the curing agent [C] was weighed at a predetermined weight ratio and mixed at 110° C. for 60 minutes to prepare a liquid curing agent liquid (curing agent [C]). The main component liquid and the curing agent liquid were mixed at 80° C. for 30 minutes using a stirrer in the proportions shown in Table 1 to dissolve the curing agent in the epoxy resin to prepare a one-liquid type epoxy resin composition. In addition, in the composition shown in Table 1, the mixing ratio of the main liquid and the curing agent liquid was selected so that the number of active hydrogen groups possessed by the glycidyl groups of the epoxy resin and the number of amino groups of the curing agent were equivalent.
(1-2) Initial Viscosity and Pot Life Viscosity was measured at 100° C. using a Brookfield viscometer TVB-15M manufactured by Toki Sangyo Co., Ltd. The minimum measured value immediately after the start of measurement was taken as the initial viscosity, and the time when the viscosity reached 50 mPa·s was taken as the pot life.
(1-3) Rapid Curing Properties Curing properties were evaluated using a DEA288 Ionic dielectric analysis device manufactured by NETZSCH, and the DEA curing degree α of uncured resin after heating at 180° C. for 40 minutes was evaluated by the following formula. A resin composition having a rapid curing characteristic was obtained when the degree of curing was 70% or more.
α(t = 40) = (log ε” ₀ - log ε” _{t = 40} ) / (log ε” ₀ - log ε” _∞ ) x 100
(where ε” ₀ is the maximum value of dielectric loss at the start of measurement, ε” _{t = 40} is the dielectric loss value at 40 minutes of measurement time, and ε” _∞ is the value at 180 minutes of measurement time. is the dielectric loss value of

[Measurement condition]
Measurement temperature: 180±2°C isothermal Measurement frequency: 1 Hz
Measurement sensor: IDEX 115/35 manufactured by NETZSCH
(2) Characteristics of cured resin product (2-1) Preparation of cured resin product After defoaming the one-part epoxy resin composition prepared in (1-1) in a vacuum, It was injected into a stainless steel mold set to have a thickness of 4 mm. It was cured at a temperature of 180° C. for 2 hours to obtain a resin cured product having a thickness of 4 mm.
(2-2) Glass transition temperature at saturated water absorption (wet-Tg)
The glass transition temperature at saturated water absorption was measured according to the SACMA 18R-94 method.
The dimensions of the resin test piece were 50 mm x 6 mm x 2 mm. Using a pressure cooker (HASTEST PC-422R8, manufactured by Espec Co., Ltd.), the prepared resin cured product test piece was subjected to water absorption treatment at 121° C. for 24 hours. Using a dynamic viscoelasticity measuring device Rheogel-E400 manufactured by UBM, the measurement frequency is 1 Hz, the temperature increase rate is 5 ° C./min, and the strain is 0.0167%. The storage modulus E' was measured up to. Log E ' is plotted against temperature, and the temperature obtained from the intersection of the approximate straight line of the flat region of log E ' and the approximate straight line of the region where E ' transitions is recorded as the glass transition temperature at saturated water absorption (wet-Tg). bottom.

(2-3) Room temperature dry flexural modulus (RTD-FM)
The test was performed according to the JIS K7171 method. At that time, a cured resin test piece was prepared with dimensions of 80 mm×10 mm×h4 mm. A bending test was performed at a distance L between fulcrums of 16×h (thickness) and a test speed of 2 m/min to measure room temperature dry bending elastic modulus (RTD-FM).
(2-4) Resin cured product toughness (deformation mode I critical stress intensity factor KIc)
The cured resin obtained in (2-1) was cut into a size of 8 mm wide (twice the thickness) and 35.2 mm long (4.4 times the width) to obtain a test piece. Initial cracks were introduced into the test piece by applying a razor cooled to the temperature of liquid nitrogen to the test piece and applying impact to the razor with a hammer to create pre-cracks. The pre-crack length was 0.45 to 0.55 times the width. According to ASTM D5045, the toughness (KIc) was measured using a universal testing machine (Shimadzu Autograph).
(3) Average particle size of resin particle component [D] The cross section of the cured resin is observed with a scanning electron microscope or a transmission electron microscope at a magnification of 25,000 times, and the diameter of 50 particles is actually measured. As the particle size, the average particle size was obtained by averaging them. In the above observation, when the particles were not perfectly circular, that is, when the particles were elliptical, the maximum diameter of the particles was taken as the particle diameter of the particles.

(4) Characteristics of CFRP (4-1) Fabrication of CFRP Carbon fiber multiaxial fabric 1 and carbon fiber multiaxial fabric 2 were cut into 300 x 300 mm, and carbon Three sheets of the multiaxial fiber woven fabric 1 and three sheets of the multiaxial woven carbon fiber fabric 2 were laminated to form a laminate by stacking a total of 6 sheets.
Further, a peel cloth Release Ply C (manufactured by AIRTECH), which is a base material having a releasability function, and Resin Flow 90HT (manufactured by AIRTECH), which is a resin diffusion base material, were laminated on the laminate. After that, a hose for forming a resin inlet and a resin outlet was arranged, the whole was covered with a nylon bag film, sealed with a sealant tape, and the inside was evacuated. Subsequently, the aluminum plate was heated to 120°C, and the pressure inside the bag was reduced to 5 torr or less. injected inside.
The bag was filled with the injected one-liquid type epoxy resin composition and impregnated into the laminate, and the temperature was raised to 180° C. and held at 180° C. for 40 minutes to obtain a carbon fiber composite material.
(4-2) Compressive strength after impact (CAI)
The CFRP obtained in (4-1) was cut into a size of 101.6 mm width×152.4 mm length to obtain a test piece for compressive strength after impact (CAI) test. Testing was performed according to ASTM D7136. After measuring the dimensions of each test piece, the specimen (sample) was subjected to an impact test using a falling weight type impact tester (Dynatup manufactured by Instron) to give an impact energy of 30.5 J. After the impact, the damaged area of the test piece was measured with an ultrasonic flaw detector (SDS3600, HIS3/HF manufactured by Kraut Kramer). After the impact, the strength test of the specimen was performed by attaching strain gauges on each side of the specimen at a position of 25.4 mm from the top and 25.4 mm from the side. After attaching the gauge, the crosshead speed of the testing machine (Autograph manufactured by Shimadzu Corporation) was set to 1.27 mm/min, and a load was applied until the specimen fractured.

(Evaluation results)
[Examples 1 to 19, Comparative Examples 1 to 6]
Table 1 shows the properties of the one-liquid epoxy resin composition, cured resin and CFRP. The one-component epoxy resin compositions of Examples 1 to 19 exhibited a low initial viscosity of 70 mPa·s or less at 100°C and a long pot life of 30 minutes or more. In addition, the DEA curing degree α after heating at 180° C. for 40 minutes was 70% or more (“◯” in Table 1), indicating rapid curing characteristics. The cured resin products of Examples 1 to 19 exhibited high toughness with a KIc of 0.8 MPa·m^1/2 or higher, a high wet-Tg of 130°C or higher, and a high RTD-FM of 2.8 GPa or higher. rice field. The CFRPs obtained in Examples 1-19 exhibited a high CAI of 250 MPa or more.
In Comparative Example 1 in which the resin particle component [D] was not used, the KIc of the cured resin obtained was as low as 0.62 MPa·m^1/2. Therefore, the CAI of CFRP obtained in Comparative Example 1 was as low as 235 MPa.
Since the epoxy resin [B] was not used in Comparative Example 2, the initial viscosity of the resin composition was as high as 350 mPa·s.
In Comparative Example 3, since (CA) liquid aromatic polyamine was not used, the initial viscosity of the resin composition was as high as 300 mPa·s or more.
Comparative Example 4 did not use (C-A) liquid aromatic polyamine and used only (C-C) aliphatic cyclic polyamine. was shortened to less than 5 minutes.
Comparative Example 5 uses only (CA) a liquid aromatic polyamine, and does not use (C-B) a solid aromatic amine containing a secondary amino group and (C-C) an aliphatic cyclic polyamine. did not show
Comparative Example 6 did not use curing agent [C], but used M-MIPA, but did not exhibit rapid curing properties.

Claims (14)

A two-liquid type epoxy resin composition comprising a base liquid and a curing agent liquid,
The main component liquid contains an epoxy resin [A] composed of a monomer containing 4 or more glycidyl groups, and an aromatic epoxy resin [B] composed of a monomer containing 2 or 3 glycidyl groups,
The curing agent liquid contains a curing agent [C], the curing agent [C] contains (CA) a liquid aromatic polyamine and (C-B) a solid aromatic amine containing a secondary amino group, ( CB) a solid aromatic amine comprising secondary amino groups comprises (C-B1) a solid aromatic amine in which the number of secondary amino groups is greater than the total number of primary and tertiary amino groups, or If not included, if not included, the curing agent [C] further includes (C-C) aliphatic cyclic polyamine,
A two-liquid type epoxy resin composition, wherein at least one of the main liquid and the curing agent liquid contains a resin particle component [D]. The constituent monomer of the epoxy resin [A] has the following chemical formula (1)

(In chemical formula (1), R ₁ to R ₄ each independently represent one selected from the group consisting of a hydrogen atom, an aliphatic hydrocarbon group, an alicyclic hydrocarbon group, and a halogen atom. , X is -CH ₂ -, -O-, -S-, -CO-, -C(=O)O-, -O-C(=O)-, -NHCO-, -CONH-, -SO ₂ represents one selected from -.)
2. The two-part epoxy resin composition according to claim 1, comprising a compound represented by The constituent monomer of the epoxy resin [A] is tetraglycidyl-4,4'-diaminodiphenyl ether, tetraglycidyl-4,4'-diaminodiphenylmethane, tetraglycidyl-3,4'-diaminodiphenyl ether or tetraglycidyl-3,3 3. The two-component epoxy resin composition according to claim 1, which is one or a combination of two or more selected from '-diaminodiphenylmethane. 4. The two-component epoxy resin composition according to any one of claims 1 to 3, wherein the main component liquid contains 50 to 90% by mass of the epoxy resin [A]. The constituent monomer of the epoxy resin [B] is selected from diglycidylaniline, diglycidyl-o-toluidine, triglycidyl-p-aminophenol, triglycidyl-m-aminophenol, bis(glycidyloxy)naphthalene and triglycidyl isocyanurate. The two-component epoxy resin composition according to any one of claims 1 to 4, which is one type or a combination of two or more types. The two-part epoxy resin composition according to any one of claims 1 to 5, wherein the resin particle component [D] has an average particle size of 1.0 µm or less. A one-component epoxy resin composition obtained by blending the main component liquid and the curing agent liquid of the two-component epoxy resin composition according to any one of claims 1 to 6. 8. The one-component epoxy resin composition according to claim 7, which has a degree of curing of 70% or more after heating at 180° C. for 40 minutes, as evaluated by dielectric curing degree measurement. A cured resin obtained by curing the one-liquid type epoxy resin composition according to claim 7 or 8. 10. The cured resin product according to claim 9, wherein the deformation mode I critical stress intensity factor KIc is 0.8 or more. A fiber-reinforced composite material comprising the cured resin according to claim 9 or 10 and a fiber-reinforced base material. 12. The fiber reinforced composite material according to claim 11, wherein said fiber reinforced substrate is a carbon fiber reinforced substrate. A method for producing a fiber-reinforced composite material, comprising combining a fiber-reinforced base material and the one-part epoxy resin composition according to claim 7 or 8 and curing the composition. A method for producing a fiber-reinforced composite material, comprising a step of impregnating a fiber-reinforced base material placed in a mold with the one-liquid epoxy resin composition according to claim 7 or 8, followed by heat curing.