JP5609040B2 - RESIN COMPOSITION FOR FIBER-REINFORCED COMPOSITE MATERIAL, CURED PRODUCT, FIBER-REINFORCED COMPOSITE MATERIAL, FIBER-REINFORCED RESIN MOLDED ARTICLE, AND METHOD FOR PRODUCING THE SAME - Google Patents

Description

  The present invention provides a fiber-reinforced composite material suitable for aircraft members, spacecraft members, automobile members, and the like, and a method for producing the same, and the fiber-reinforced composite because it exhibits excellent fluidity and excellent mechanical strength in the cured product. The present invention relates to a matrix resin material.

  An epoxy resin composition containing an epoxy resin and its curing agent as essential components is excellent in various physical properties such as high heat resistance, moisture resistance, and dimensional stability, so that it is a semiconductor encapsulant, a printed wiring board, a build-up board, a resist ink. Electronic parts such as conductive paste, conductive adhesives such as conductive paste and other adhesives, liquid sealing materials such as underfill, liquid crystal sealing materials, flexible substrate coverlays, build-up adhesive films, paints, photoresist materials, Widely used in color materials, fiber reinforced composite materials, etc.

  Among these, in particular, fiber reinforced resin molded products obtained by impregnating and curing reinforcing fibers as a matrix component with an epoxy resin and a curing agent are not only light weight and high strength, but also have excellent high heat resistance, strength, and low strength. There is a high demand in general industrial fields such as the automobile industry and the aerospace industry because they have various performances such as cure shrinkage, chemical resistance and high elastic modulus.

  However, since an epoxy resin is generally a high-viscosity fluid or solid at room temperature, it is necessary to heat the resin component in order to ensure a practical level of fluidity of the epoxy resin in the step of impregnating the fiber reinforcement with resin. However, the curing of the epoxy resin is accelerated by heating, and on the contrary, there has been a problem that the viscosity is increased and the impregnation is poor. In particular, in the field of carbon fiber reinforced thermosetting plastics (CFRP), the molding technology based on the resin transfer molding (RTM) method, which has been spreading in recent years due to overwhelming cycle time and low equipment cost, From the viewpoint of cycling, the low viscosity and high fluidity of thermosetting resin materials have become important issues.

  Conventionally, as means for improving fluidity in epoxy resin materials for CFRP matrix, aliphatic epoxy compounds represented by 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, or N, N, Polyglycidylamine typified by N ', N'-tetraglycidyldiaminodiphenylmethane is blended with acrylic acid, styrene and a radical polymerization initiator to prepare a liquid composition, which is impregnated into a carbon fiber substrate and heated. In addition, a technique is known in which a molded product is obtained by performing a radical polymerization while reacting an epoxy group with acrylic acid (see Patent Document 1 below).

  However, a composition in which such an aliphatic epoxy compound or polyglycidylamine is blended with acrylic acid, styrene, and a radical polymerization initiator is excellent in fluidity, excellent in impregnation into fiber reinforcement, and cured. Although the elastic modulus was high, it was brittle and inferior in toughness, so that sufficient strength could not be obtained especially when it was made into a fiber-reinforced resin molded product.

  On the other hand, as an epoxy resin material suitable for the RTM method in CFRP applications, for example, an epoxy equivalent of 200 g / eq. The following bisphenol F type epoxy resin is used as the main agent, and the fluidity of the thermosetting resin component is improved by using an aromatic polyamine that is liquid at room temperature and a Lewis acid / base complex as the curing agent component. In addition, a technique for further improving low-temperature curability and improving CFRP productivity in the RTM method is known (see Patent Document 2).

  However, the epoxy equivalent of 200 g / eq. The following bisphenol F type epoxy resin, aromatic polyamine that is liquid at room temperature, and thermosetting resin material containing a complex of Lewis acid and base are designed to reduce the viscosity of the epoxy resin itself, but the entire composition As the viscosity is still high, for example, heating at around 100 ° C. is indispensable at the time of resin injection in RTM molding, there is a risk of thickening due to the curing reaction, the running cost is increased in terms of energy, and the molding cycle time is reduced. It could not be shortened sufficiently. In addition, the toughness of the cured product is not sufficient, making it difficult to apply to fields that require high strength such as the automobile industry and aerospace industry.

Japanese Patent Application Laid-Open No. 55-110115 JP 2006-265434 A

  Therefore, the problem to be solved by the present invention is that the resin composition for fiber reinforced composite material, which has excellent fluidity and impregnation into a fiber base material, and gives excellent toughness to a cured product, its cured product, and molding An object of the present invention is to provide a fiber-reinforced composite material that gives an excellent strength to a product, a fiber-reinforced resin molded product that is excellent in strength, and a method for manufacturing a fiber-reinforced resin molded product that has good productivity.

As a result of intensive investigations to solve the above problems, the present inventors have determined that, as a thermosetting resin component impregnated and cured in a fiber reinforcing agent, a bisphenol type epoxy resin (A), the following structural formula (1)

（式中、Ｒ^１は炭素原子数２〜１０の飽和脂肪族炭化水素基、Ｘはエステル結合又はカーボネート結合、Ｒ^２は炭素原子数２〜１０の飽和脂肪族炭化水素基、又は芳香族炭化水素基を表し、ｎは１〜５の整数を示す。）
で表される酸基含有ラジカル重合性単量体（Ｂ）、及びラジカル重合開始剤（Ｃ）を必須成分とする組成物を用い、これらを連続的乃至同時に硬化させる、所謂イン・サイチュー重合反応による硬化を行うこと、即ち、前記酸基含有重合性単量体（Ｂ）中の酸基を前記エポキシ樹脂（Ａ）中のエポキシ基と反応させると共に、該酸基含有重合性単量体（Ｂ）に起因するラジカル重合性基を重合させることにより、硬化前では、低温域、例えば２５℃の常温であっても優れた流動性を発現すると伴に、硬化後は優れた靱性を発現することを見出し、本発明を完成するに至った。

(Wherein R ¹ is a saturated aliphatic hydrocarbon group having 2 to 10 carbon atoms, X is an ester bond or carbonate bond, R ² is a saturated aliphatic hydrocarbon group having 2 to 10 carbon atoms, or aromatic carbonization. Represents a hydrogen group, and n represents an integer of 1 to 5.)
A so-called in situ polymerization reaction in which a radically polymerizable monomer (B) and a radical polymerization initiator (C) represented by the formula are used as essential components and these are cured continuously or simultaneously. That is, the acid group in the acid group-containing polymerizable monomer (B) is reacted with the epoxy group in the epoxy resin (A), and the acid group-containing polymerizable monomer ( By polymerizing the radically polymerizable group resulting from B), before curing, it exhibits excellent fluidity even in a low temperature range, for example, at room temperature of 25 ° C., and also exhibits excellent toughness after curing. As a result, the present invention has been completed.

That is, the present invention relates to a bisphenol type epoxy resin (A), the following structural formula (1)

（式中、Ｒ^１は炭素原子数２〜１０の飽和脂肪族炭化水素基、Ｘはエステル結合又はカーボネート結合、Ｒ^２は炭素原子数２〜１０の飽和脂肪族炭化水素基、又は芳香族炭化水素基を表し、ｎは１〜５の整数を示す。）
で表される酸基含有ラジカル重合性単量体（Ｂ）、及びラジカル重合開始剤（Ｃ）を必須成分とし、前記ビスフェノール型エポキシ樹脂（Ａ）中のエポキシ基と、前記酸基含有ラジカル重合性単量体（Ｂ）中の酸基との当量比［エポキシ基／酸基］が１／１〜１／０．１となる割合であることを特徴とする繊維強化複合材料用樹脂組成物に関する。

(Wherein R ¹ is a saturated aliphatic hydrocarbon group having 2 to 10 carbon atoms, X is an ester bond or carbonate bond, R ² is a saturated aliphatic hydrocarbon group having 2 to 10 carbon atoms, or aromatic carbonization. Represents a hydrogen group, and n represents an integer of 1 to 5.)
The acid group-containing radical polymerizable monomer (B) and the radical polymerization initiator (C) represented by the formula are essential components , the epoxy group in the bisphenol-type epoxy resin (A), and the acid group-containing radical. polymerizable monomer (B) equivalent ratio [epoxy groups / group] is 1 / 1-1 / 0.1 and consisting ratio der Rukoto fiber-reinforced composite material for resin, wherein the acid groups in the Relates to the composition.

  The present invention further relates to a cured product obtained by subjecting the resin composition for fiber-reinforced composite material to an in situ polymerization reaction.

  The present invention further relates to a fiber-reinforced composite material comprising the resin composition for fiber-reinforced composite material and reinforcing fibers as essential components.

The present invention further relates to a fiber reinforced resin molded product comprising a cured product of the resin composition for fiber reinforced composite material and reinforcing fibers as essential components.
The present invention is further characterized by injecting and impregnating the resin composition for fiber-reinforced composite material into a base material composed of reinforcing fibers arranged in a mold, followed by curing by in-situ polymerization reaction. The present invention relates to a method for producing a fiber-reinforced resin molded product.

According to the present invention, the resin composition for a fiber reinforced composite material that has excellent fluidity, excellent impregnation into a fiber substrate, and excellent toughness in a cured product, and excellent toughness in the cured product and molded product. It is possible to provide a fiber-reinforced composite material to be provided, a fiber-reinforced resin molded article having excellent toughness, and a method for producing a fiber-reinforced resin molded article having good productivity.
Therefore, if the resin composition for fiber reinforced composite materials of the present invention is used, a higher cycle can be achieved and a high-strength fiber reinforced resin molded product can be obtained in the process for producing epoxy CFRP.

Hereinafter, the present invention will be described in detail.
The resin composition for fiber-reinforced composite material of the present invention includes an epoxy resin (A), an acid group-containing radical polymerizable monomer (B) having an aliphatic ester bond or an aliphatic carbonate bond as its thermosetting resin component. And a radical polymerization initiator (C) as essential components. Then, after impregnating the composition into the fiber reinforcement, the reaction is performed at once, that is, the reaction between the epoxy group and the acid group and the polymerization reaction of the radical polymerizable group are distinguished as reaction steps. The reaction is characterized in that both reactions are carried out simultaneously or continuously. Thus, by curing by in-situ polymerization reaction, fluidity is remarkably high before curing, and high cycle can be achieved in the RTM method, and toughness in the cured product can be dramatically improved. On the other hand, the cured product obtained by the in-situ polymerization reaction includes an epoxy resin (A) and an acid group-containing radical polymerizable monomer (B) having an aliphatic ester bond or an aliphatic carbonate bond (hereinafter referred to as this). It is abbreviated as “acid group-containing radically polymerizable monomer (B)”) to give a vinyl ester, and then the strength of the cured product can be further increased as compared with the case of radical polymerization. it can.

As used herein, the epoxy resin (A), for example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, bisphenol AD type epoxy resin, bisphenol type epoxy resin etc., Te tiger-bisphenol A type epoxy Resin etc. are mentioned. Moreover, the said epoxy resin may be used independently and may mix 2 or more types.

These bisphenol type epoxy resins, especially epoxy resin itself is a low viscosity, enhanced because of excellent impregnation into fibers, and heat resistance of the cured product, rather better or balance of properties strength point is good RaYoshimi In particular, the epoxy equivalent is 500 g / eq. From the viewpoint of excellent fluidity at room temperature and good impregnation into reinforcing fibers. The following are preferable, and bisphenol A type epoxy resins are particularly preferable from the viewpoint of excellent balance between the rigidity of the cured product and heat and humidity resistance. The epoxy equivalent of the bisphenol-type epoxy resin is 100 to 300 g / eq. It is particularly preferable that the range is

Epoxy resin (A) used in the present invention, as described above, is a bisphenol-type epoxy resins, the present invention may be used in combination depending on the purpose of these bisphenol type epoxy resins and other epoxy resins. In that case, from the viewpoint of capable of bisphenol type epoxy resins 1 00 parts by weight per other things epoxy resin is a ratio of the 5 to 80 parts by weight the performance of the bisphenol type epoxy resins can be sufficiently exhibited. Other epoxy resins used here include, for example, orthocresol novolak type epoxy resin, phenol novolak type epoxy resin, naphthol novolak type epoxy resin, bisphenol A novolak type epoxy resin, brominated phenol phenol novolak type epoxy resin, alkylphenol novolak type epoxy resin. Resin, bisphenol S novolac type epoxy resin, alkoxy group-containing novolac type epoxy resin, novolac type epoxy resin such as brominated phenol novolak type epoxy resin, etc .; phenol aralkyl type epoxy resin (commonly known as epoxidized zylock resin), resorcin di Glycidyl ether, hydroquinone diglycidyl ether, catechol diglycidyl ether, biphenyl type epoxy resin, Bifunctional epoxy resins such as lamethylbiphenyl type epoxy resin, sulfur-containing epoxy resin, stilbene type epoxy resin, triglycidyl isocyanurate, triphenylmethane type epoxy resin, tetraphenylethane type epoxy resin, dicyclopentadiene-phenol addition Reactive epoxy resin, biphenyl-modified novolac epoxy resin (epoxidized polyhydric phenol resin in which phenol nucleus is linked by bismethylene group), alkoxy group-containing novolac epoxy resin, alkoxy group-containing phenol aralkyl resin, brominated phenol novolak type An epoxy resin etc. are mentioned. These other epoxy resins may be used alone or in combination of two or more.

  Next, the acid group-containing radical polymerizable monomer (B) used in the present invention is an essential component for imparting excellent strength to the cured product and improving toughness, and the following structural formula (1)

（式中、Ｒ^１は炭素原子数２〜１０の飽和脂肪族炭化水素基、Ｘはエステル結合又はカーボネート結合、Ｒ^２は炭素原子数２〜１０の飽和脂肪族炭化水素基、又は芳香族炭化水素基を表し、ｎは１〜５の整数を示す。）で表される化合物が挙げられる。

(Wherein R ¹ is a saturated aliphatic hydrocarbon group having 2 to 10 carbon atoms, X is an ester bond or carbonate bond, R ² is a saturated aliphatic hydrocarbon group having 2 to 10 carbon atoms, or aromatic carbonization. Represents a hydrogen group, and n represents an integer of 1 to 5.).

In the general formula (1), R ¹ is a saturated aliphatic hydrocarbon group having 2 to 10 carbon atoms, and R ² is a saturated aliphatic hydrocarbon group having 2 to 10 carbon atoms, or aromatic carbonization Since it is a hydrogen group, the crosslink density does not become too high in the cured product, and appropriate flexibility can be imparted, and toughness can be dramatically increased.

  Here, in the structural formula 1, X having an ester bond is a compound obtained by reacting a hydroxyalkyl (meth) acrylate with a saturated aliphatic polyvalent carboxylic acid having 2 to 10 carbon atoms; Compound obtained by reacting alkyl (meth) acrylate with aromatic dicarboxylic acid or acid anhydride thereof; hydroxyalkyl (meth) acrylate, saturated aliphatic diol having 2 to 10 carbon atoms, and 2 to 2 carbon atoms Compound obtained by reacting 10 saturated aliphatic polyvalent carboxylic acid; obtained by reacting hydroxyalkyl (meth) acrylate, saturated aliphatic diol having 2 to 10 carbon atoms, and aromatic dicarboxylic acid Compounds.

  Here, examples of the hydroxyalkyl (meth) acrylate include β-hydroxyethyl methacrylate and β-hydroxyethyl acrylate.

  Examples of the saturated aliphatic polyvalent carboxylic acid having 2 to 10 carbon atoms include succinic anhydride, adipic acid, tetrahydrophthalic acid, and cyclohexanedicarboxylic acid. Examples of the aromatic dicarboxylic acid or its acid anhydride include phthalic acid, phthalic anhydride, isophthalic acid, terephthalic acid, tetrabromophthalic acid, and tetrabromophthalic anhydride.

  Further, as the saturated aliphatic diol having 2 to 10 carbon atoms, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 2-methyl-1,3-propanediol, 2,2-dimethyl-1,3- Propanediol, 3-methyl-1,5-pentanediol, 1,2-cyclohexanediol, 1,3-cyclohexanediol, 1,4-cyclohexanediol, 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol 1,4-cyclohexanedimethanol, 1,2-cyclohexanediethanol, 1,3-cyclohexane Ethanol, 1,4-cyclohexane diethanol, and the like. Of these, butanediol, pentanediol, hexanediol, cyclohexanediol, and cyclohexanedimethanol having 4 to 8 carbon atoms are preferred from the viewpoint of excellent compatibility with the epoxy resin (A).

  Moreover, as what has a carbonate bond as X in the said Structural formula (1), for example, after obtaining polycarbonate diol by transesterification of the said C2-C10 aliphatic diol and dialkyl carbonate (meta) The compound obtained by making it react with acrylic acid or its derivative (s) is mentioned.

  Among these, X is preferably an ester bond in the structural formula (1) from the viewpoint that moderate hardness can be imparted to the cured product, in particular, β-hydroxyethyl methacrylate and succinic anhydride. Preference is given to 3-[[2- (methacryloyloxy) ethoxy] carbonyl] propionic acid which is an adduct, and 2-methacryloyloxyethyl hexahydrophthalic acid which is an adduct of β-hydroxyethyl methacrylate and hexahydrophthalic acid.

  The radical polymerization initiator (C) used in the present invention is not particularly limited as long as it is used as a thermal radical polymerization initiator. For example, methyl ethyl ketone peroxide, methylcyclohexanone peroxide, methyl acetoacetate peroxide, acetylacetone peroxide, 1, 1-bis (t-butylperoxy) 3,3,5-trimethylcyclohexane, 1,1-bis (t-hexylperoxy) cyclohexane, 1,1-bis (t-hexylperoxy) 3,3,5 -Trimethylcyclohexane, 1,1-bis (t-butylperoxy) cyclohexane, 2,2-bis (4,4-di-t-butylperoxycyclohexyl) propane, 1,1-bis (t-butylperoxy) ) Cyclododecane, n-butyl 4,4-bis (t-butyl pero) B) Valerate, 2,2-bis (t-butylperoxy) butane, 1,1-bis (t-butylperoxy) -2-methylcyclohexane, t-butyl hydroperoxide, P-menthane hydroperoxide, 1,1,3,3-tetramethylbutyl hydroperoxide, t-hexyl hydroperoxide, dicumyl peroxide, 2,5-dimethyl-2,5-bis (t-butylperoxy) hexane, α, α '-Bis (t-butylperoxy) diisopropylbenzene, t-butylcumyl peroxide, di-t-butyl peroxide, 2,5-dimethyl-2,5-bis (t-butylperoxy) hexyne-3, Isobutyryl peroxide, 3,5,5-trimethylhexanoyl peroxide, octanoyl peroxide Id, lauroyl peroxide, cinnamic acid peroxide, m-toluoyl peroxide, benzoyl peroxide, diisopropyl peroxydicarbonate, bis (4-t-butylcyclohexyl) peroxydicarbonate, di-3-methoxybutylperoxy Dicarbonate, di-2-ethylhexylperoxydicarbonate, di-sec-butylperoxydicarbonate, di (3-methyl-3-methoxybutyl) peroxydicarbonate, di (4-t-butylcyclohexyl) peroxy Dicarbonate, α, α′-bis (neodecanoylperoxy) diisopropylbenzene, cumylperoxyneodecanoate, 1,1,3,3-tetramethylbutylperoxyneodecanoate, 1-cyclohexyl- 1-methyl Ruethyl peroxyneodecanoate, t-hexylperoxyneodecanoate, t-butylperoxyneodecanoate, t-hexylperoxypivalate, t-butylperoxypivalate, 2,5-dimethyl -2,5-bis (2-ethylhexanoylperoxy) hexane, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, 1-cyclohexyl-1-methylethylperoxy-2- Ethyl hexanoate, t-hexylperoxy-2-ethylhexanoate, t-butylperoxy-2-ethylhexanoate, t-butylperoxyisobutyrate, t-butylperoxymaleic acid, t -Butylperoxylaurate, t-butylperoxy-3,5,5-trimethylhexanoate , T-butylperoxyisopropyl monocarbonate, t-butylperoxy-2-ethylhexyl monocarbonate, 2,5-dimethyl-2,5-bis (benzoylperoxy) hexane, t-butylperoxyacetate, t-hexyl Peroxybenzoate, t-butylperoxy-m-toluoylbenzoate, t-butylperoxybenzoate, bis (t-butylperoxy) isophthalate, t-butylperoxyallyl monocarbonate, 3,3 ′, 4 Examples include 4′-tetra (t-butylperoxycarbonyl) benzophenone.

  The blending ratio of the epoxy resin (A), the acid group-containing polymerizable monomer (B), and the radical polymerization initiator (C) detailed above is the same as the epoxy group in the epoxy resin (A) and the acid. The equivalent ratio [epoxy group / acid group] with the acid group in the group-containing polymerizable monomer (B) is a ratio of 1/1 to 1 / 0.1, and the component (A) to ( C) The balance of the fluidity of the composition and the toughness of the cured product is good when the blending amount of the radical polymerization initiator (C) is from 0.01 to 3 parts by mass per 100 parts by mass of the total component. In particular, the equivalent ratio [epoxy group / acid group] of the epoxy group in the epoxy resin (A) and the acid group in the acid group-containing polymerizable monomer (B) is 1 in particular. / 1 to 1 / 0.48 is a better balance of fluidity and toughness of the cured product. Preferable from the point. In particular, the epoxy resin (A) has an epoxy equivalent of 500 g / eq. In the case of using the following bisphenol type epoxy resin, the blending ratio is such that the epoxy resin (A) is 50 to 90 parts by mass, the acid group-containing polymerizable monomer (B) is 10 to 40 parts by mass, and It is preferable from the point of fluidity | liquidity and the impregnation property to a reinforced fiber that it is a ratio from which a radical polymerization initiator (C) will be 0.5-2 mass parts.

  In the resin composition for fiber-reinforced composite material of the present invention, in addition to the epoxy resin (A), the acid group-containing polymerizable monomer (B), and the radical polymerization initiator (C), From the viewpoint of improving strength and heat resistance, the unsaturated carboxylic acid or its anhydride, which is a radical polymerizable monomer (D) having a molecular weight of 160 or less (hereinafter referred to as “low molecular weight acid group-containing polymerizable monomer”). (It is abbreviated as “mer (D)”). Specific examples of the low molecular weight acid group-containing polymerizable monomer (D) used here include acrylic acid, methacrylic acid, maleic acid, fumaric acid, crotonic acid, itaconic acid, and acid anhydrides thereof. It is preferable from the point that the effect of improving the fluidity of the composition is remarkable.

  Among these, acrylic acid and methacrylic acid are particularly preferable, and methacrylic acid is particularly preferable from the viewpoint of the effect of reducing the viscosity and the strength of the cured product. Specifically, the use ratio of the low molecular weight acid group-containing polymerizable monomer (D) is as follows: the acid group-containing polymerizable monomer (B) and the low molecular weight acid group-containing polymerizable monomer (D). And the molar ratio [acid group-containing polymerizable monomer (B) / low molecular weight acid group-containing polymerizable monomer (D)] is a ratio of 95/5 to 20/80. It is preferable from the viewpoint that the excellent cured product strength is further improved. Furthermore, in this case, the total number of moles of acid groups (Bn) of the acid group-containing polymerizable monomer (B) relative to the total number of moles (An) of epoxy groups in the epoxy resin (A) and the content of low molecular weight acid groups The ratio “(An) / [(Bn) + (Dn)]” of the total number of moles (Dn) of acid groups and acid anhydride groups in the polymerizable monomer (D) is 1/1 to A range of 1 / 0.48 is preferable from the viewpoint of a composition having good fluidity and curability.

  In the fiber-reinforced composite material resin composition of the present invention, an aromatic vinyl compound or (meth) acrylic acid ester (E) (hereinafter referred to as “radical” from the viewpoints of improving the fluidity of the composition and adjusting the viscosity. (Abbreviated as “polymerizable monomer (E)”).

  In the radical polymerizable monomer (E), examples of the aromatic vinyl compound include styrene, methylstyrene, halogenated styrene, and divinylbenzene.

  On the other hand, as the (meth) acrylic acid esters, various monofunctional (meth) acrylates and polyfunctional (meth) acrylates can be used. For example, monofunctional (meth) acrylates include, for example, methyl, ethyl, propyl , Butyl, 3-methoxybutyl, amyl, isoamyl, 2-ethylhexyl, octyl, isooctyl, nonyl, isononyl, decyl, isodecyl, dodecyl, tridecyl, hexadecyl, octadecyl, stearyl, isostearyl, cyclohexyl, benzyl, methoxyethyl, butoxyethyl , Having a substituent such as phenoxyethyl, nonylphenoxyethyl, glycidyl, dimethylaminoethyl, diethylaminoethyl, isobornyl, dicyclopentanyl, dicyclopentenyl, dicyclopentenyloxyethyl ( Data) acrylate, and the like.

Examples of the polyfunctional (meth) acrylate include 1,3-butylene glycol, 1,4-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, and 1,6-hexanediol. Di (meth) such as neopentyl glycol, 1,8-octanediol, 1,9-nonanediol, tricyclodecane dimethanol, ethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, polypropylene glycol Di (meth) acrylate of diol obtained by adding 2 mol or more of ethylene oxide or propylene oxide to 1 mol of 1,6-hexanediol, acrylate, tris (2-hydroxyethyl) isocyanurate di (meth) acrylate , Di (meth) acrylate of diol obtained by adding 4 mol or more of ethylene oxide or propylene oxide to 1 mol of neopentyl glycol, Diol obtained by adding 2 mol of ethylene oxide or propylene oxide to 1 mol of bisphenol A Di (meth) acrylate, 3 mol or more of ethylene oxide or propylene oxide added to 1 mol of trimethylolpropane, diol or tri (meth) acrylate of triol, 4 mol or more of ethylene oxide or propylene per 1 mol of bisphenol A Di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra of diol obtained by adding oxide Meth) acrylate,
Examples include di (pentaerythritol) poly (meth) acrylate, ethylene oxide-modified phosphoric acid (meth) acrylate, and ethylene oxide-modified alkylated phosphoric acid (meth) acrylate.

  Of these, styrene, methylstyrene, halogenated styrene, divinylbenzene, and monofunctional (meth) acrylate are preferred, and particularly styrene or monofunctional (meth) acrylate, since the viscosity of the varnish can be further reduced. In particular, styrene is preferable because the strength of the cured product is excellent.

  Here, when the radical polymerizable monomer (E) is used, the total mass of the components (A) to (D) described above and the radical polymerizable monomer (E) is 100 parts by mass. The ratio of the radical polymerizable monomer (E) in the range of 50 parts by mass to 5 parts by mass, particularly 35 parts by mass to 5 parts by mass can enhance the fluidity without reducing the strength of the cured product. It is preferable from the viewpoint of better impregnation into the fiber.

  In the present invention, in addition to the acid group-containing polymerizable monomer (B), a low molecular weight acid group-containing polymerizable monomer (D) and a radical polymerizable monomer (E) are used in combination. When doing, it is preferable from a sclerosing | hardenable point that the usage-amount of a radical polymerization initiator (C) is 0.01-5 mass parts per 100 mass parts of compositions.

  The resin composition for fiber-reinforced composite material of the present invention can further appropriately use a reaction catalyst for reacting the epoxy resin (A) with the acid group-containing polymerizable monomer (B). . Examples of the reaction catalyst include tertiary amines such as triethylamine, N, N-benzyldimethylamine, N, N-dimethylphenylamine, N, N-dimethylaniline or diazabicyclooctane; trimethylbenzylammonium chloride, triethylbenzyl Quaternary ammonium salts such as ammonium chloride and methyltriethylammonium chloride; phosphines such as triphenylphosphine and tributylphosphine; imidazoles such as 2-methylimidazole, 1,2-dimethylimidazole and 2-ethyl-4-methylimidazole; Examples include triphenyl stibine and anion exchange resin. The amount of the catalyst used is preferably in the range of 0.01 to 5% by mass, particularly 0.05 to 5% by mass in the resin composition for fiber-reinforced composite material that is a varnish from the viewpoint of excellent reactivity. .

  The resin composition for fiber-reinforced composite material of the present invention described in detail above can further use a flame retardant from the viewpoint of imparting flame retardancy to the cured product. Examples of the flame retardant used here include halogen-based flame retardants such as polybrominated diphenyl ether, polybrominated biphenyl, tetrabromobisphenol A, and tetrabromobisphenol A type epoxy resin, and phosphorus-based flame retardants, nitrogen-based flame retardants, and silicones. Non-halogen flame retardants such as flame retardants, inorganic flame retardants, and organic metal salt flame retardants. Of these, non-halogen flame retardants are preferred because of the recent high demand for non-halogens.

  Various compounding agents, such as a silane coupling agent, a mold release agent, an ion trap agent, and a pigment, can be added to the resin composition for fiber-reinforced composite materials of the present invention as necessary.

  The resin composition for fiber-reinforced composite material of the present invention can be easily obtained as a liquid composition by uniformly stirring the above-described components.

  The resin composition for fiber-reinforced composite material of the present invention can be varnished without using an organic solvent or by using a very small amount. Here, acetone, methyl ethyl ketone, toluene, xylene, methyl isobutyl ketone, ethyl acetate, ethylene glycol monomethyl ether, N, N-dimethylformamide, methanol, ethanol and the like can be mentioned. The amount of the organic solvent used is preferably 10% by mass or less in the composition, and it is particularly preferable that the organic solvent is not substantially used.

  The resin composition for fiber-reinforced composite material of the present invention, that is, the varnish for impregnating reinforcing fibers has higher fluidity than the conventional one and expresses excellent toughness after curing. -It is preferable that the viscosity (E-type viscometer) in the temperature condition at the time of hardening, especially the temperature condition at the time of molding by the RTM method is 500 mPa · s or less. In the present invention, since such performance appears remarkably, a varnish in which each of the above components is uniformly mixed is an E-type viscometer (“TV” manufactured by Toki Sangyo Co., Ltd.) at 25 ° C. after 1 hour from the varnish adjustment. It is preferable that the viscosity measured using a “-20 type” cone plate type) is 500 mPa · s or less, specifically 5 to 500 mPa · s. In the present invention, the varnish viscosity is thus lower than that of the conventional CFRP varnish, so that the heating temperature when impregnating the varnish into the fiber reinforcement is kept low, or in the normal temperature range of 5 to 40 ° C. Impregnation with is possible. Furthermore, the varnish is excellent in storage stability, and even after one week has passed since the varnish adjustment, the viscosity is slight, and the viscosity condition of 5 to 500 mPa · s can be maintained at 25 ° C. . On the other hand, a molded product obtained by impregnating a fiber reinforcing material and curing it by an in-situ polymerization reaction while exhibiting such a low viscosity varnish exhibits excellent strength. In view of such remarkable performance of the present invention, the viscosity is preferably 300 mPa · s or less, and particularly an epoxy equivalent of 500 g / eq. When the following bisphenol type epoxy resin is used, the viscosity is preferably 200 mPa · s or less. Thus, an epoxy equivalent of 500 g / eq. When the following bisphenol type epoxy resin is used, a cured product and a molded product having excellent toughness can be obtained even if the viscosity is adjusted to an extremely low viscosity of 200 mPa · s or less.

  As described above, the cured product of the resin composition for fiber-reinforced composite material of the present invention is obtained by in situ polymerization reaction. Here, as described above, the in-situ polymerization reaction means that both reactions can be performed simultaneously or continuously without distinguishing the reaction between the epoxy group and the acid group and the polymerization reaction of the radical polymerizable group as reaction steps. Is what you do. Here, as described above, the in-situ polymerization reaction means that both reactions can be performed simultaneously or continuously without distinguishing the reaction between the epoxy group and the acid group and the polymerization reaction of the radical polymerizable group as reaction steps. Is what you do.

  Specifically, the curing temperature at the time of performing the in-situ polymerization reaction is preferably in the temperature range of 50 to 250 ° C., and in particular, cured at 50 to 100 ° C. to obtain a tack-free cured product. Then, it is preferable to further process at a temperature of 120 to 200 ° C.

  The fiber-reinforced composite material of the present invention comprises the above-described resin composition for fiber-reinforced composite material and reinforcing fibers as essential components, and specifically, a varnish obtained by uniformly mixing the above-described components. That is, what is obtained by impregnating a reinforcing substrate made of reinforcing fibers with a resin composition for fiber-reinforced composite materials is mentioned.

  Therefore, the above-mentioned cured product is obtained by impregnating a reinforcing base material composed of reinforcing fibers with the resin composition for fiber-reinforced composite material, and then performing in-situ polymerization reaction.

  Here, the reinforcing fiber may be any of a twisted yarn, an untwisted yarn, or a non-twisted yarn, but the untwisted yarn or the untwisted yarn has both the moldability and mechanical strength of the fiber-reinforced plastic member, preferable. Furthermore, the form of a reinforced fiber can use what the fiber direction arranged in one direction, and a textile fabric. The woven fabric can be freely selected from plain weaving, satin weaving, and the like according to the site and use. Specifically, since it is excellent in mechanical strength and durability, carbon fiber, glass fiber, aramid fiber, boron fiber, alumina fiber, silicon carbide fiber and the like can be mentioned, and two or more of these can be used in combination. Among these, carbon fiber is preferable from the viewpoint that the strength of the molded product is particularly good. As the carbon fiber, various types such as polyacrylonitrile-based, pitch-based, and rayon-based can be used. Among these, a polyacrylonitrile-based one that can easily obtain a high-strength carbon fiber is preferable. Here, the use amount of the reinforcing fiber when the varnish is impregnated into a reinforcing substrate made of reinforcing fibers to form a fiber-reinforced composite material is such that the volume content of the reinforcing fiber in the fiber-reinforced composite material is 40 to 85%. The amount is preferably in the range.

  The fiber-reinforced resin molded product of the present invention is a molded product having a cured product of a resin composition for fiber-reinforced composite material and reinforcing fibers, specifically, the amount of reinforcing fibers in the fiber-reinforced resin molded product is: The volume content is preferably in the range of 40 to 85%, particularly in the range of 50 to 70% from the viewpoint of strength.

  As a method for producing such a fiber reinforced resin molded article, a fiber aggregate is laid on a mold, and a hand layup method or a spray-up method in which the varnish is laminated in multiple layers, either a male type or a female type, Vacuum bag method in which a base made of reinforcing fibers is stacked and impregnated while impregnating varnish, covered with a flexible mold that allows pressure to act on the molded product, and hermetically sealed is vacuum (reduced pressure) molding, reinforcing fibers in advance SMC press method in which a varnish containing varnish is formed into a sheet is compression-molded with a mold, RTM method in which the varnish is injected into a mating die laid with fibers, and a prepreg is produced by impregnating the varnish into a reinforcing fiber, There are methods such as baking this in a large autoclave. Among these, the RTM method is particularly preferred because of its excellent varnish fluidity. Preferred.

  Specifically, the method for producing a fiber reinforced resin molded article by the RTM method is to inject and impregnate the resin composition for fiber reinforced composite material into a base material composed of reinforcing fibers arranged in a mold. A method of curing by in-situ polymerization reaction may be mentioned.

  Examples of the base material made of reinforcing fibers include woven fabrics made of reinforcing fibers, knits, mats, and blades, and these are further laminated, shaped, and used by means such as binders and stitches. It may be used as a preform having a fixed form.

  Moreover, as a type | mold, the closed closed mold which consists of materials, such as iron, steel, aluminum, FRP, wood, gypsum, is mentioned.

  The fiber reinforced resin molded article by the RTM method is used to reduce the pressure in the cavity of a mold in which a substrate made of reinforcing fibers is disposed, and to reduce the pressure in the cavity and the external pressure of the resin composition for fiber reinforced composite material. It is preferable to use a vacuum RTM molding method in which the pressure difference is used to inject into the cavity and the substrate is impregnated. Specifically, the substrate made of reinforcing fibers is applied along the lower mold surface. Then, the upper mold and the lower mold are clamped, the mold cavity is depressurized, the base material is impregnated with the resin composition for fiber reinforced composite material, and then in-situ under the curing temperature conditions described above. The method of hardening is mentioned. At this time, it is preferable to apply a gel coat to the mold surface before disposing the base material made of reinforcing fibers on the mold surface of the lower mold, from the viewpoint of improving the appearance of the molded product. After curing, the desired fiber-reinforced resin molded product can be obtained by demolding. In the present invention, post-curing may be performed at a higher temperature after demolding.

  In addition to the reinforcing fiber substrate, a foam core, a honeycomb core, a metal part, and the like may be installed in the mold, and a composite material integrated with these may be used. In particular, a sandwich structure obtained by placing and molding carbon fiber substrates on both sides of a foam core is lightweight and has a large bending rigidity, and thus is useful as an outer plate material for automobiles, aircrafts and the like.

  Applications of the fiber-reinforced resin molded article thus obtained include sports equipment such as fishing rods, golf shafts, bicycle frames, automobiles, aircraft frames or body materials, spacecraft members, wind power generator blades, and the like. . In particular, since automotive members, aircraft members, and spacecraft members are required to have high heat resistance and strength, the fiber-reinforced resin molded product of the present invention is suitable for these uses. It is suitable as a member for automobiles such as structural members, bumpers, fenders, front floors, door inner panels, door outer panels, panel members such as hood panels, and interior parts such as instrument panels. Furthermore, it can be used as a member of not only a gasoline vehicle but also a diesel vehicle, a biodiesel vehicle, a fuel cell vehicle, a hybrid vehicle, an electric vehicle and the like.

Next, the present invention will be specifically described with reference to Examples and Comparative Examples. In the following, “parts” and “%” are based on weight unless otherwise specified. In addition, each physical property evaluation was measured on condition of the following.
1) Varnish viscosity: Measured at 25 ° C. using an E-type viscometer (“TV-20 type” cone plate type manufactured by Toki Sangyo Co., Ltd.).
2) Bending strength and flexural modulus of resin plate: compliant with JIS K6911.
3) Flexural strength of carbon fiber reinforced composite material: conformed to JIS K7074.

Examples 1 to 3 and Comparative Examples 1 to 4
1. Epoxy resin composition blending According to the blending shown in Table 1 below, each main blending component was blended using a stirrer to obtain an epoxy resin composition. The varnish viscosity when 1 hour passed after this epoxy resin composition adjustment was evaluated.
2. Preparation of cured resin plate of epoxy resin A cured resin plate was obtained under the following curing conditions A, B, or C, and then various evaluation tests were performed. The results are shown in Table 1. The curing conditions employed in each example and comparative example are shown in Table 1.
[Curing conditions A]
The epoxy resin composition is poured into a mold gap in which a spacer (silicone tube) having a thickness of 2 mm is sandwiched between glass plates, cured in an oven at 170 ° C. for 10 minutes, and then the cured product is taken out of the mold and a resin cured plate Got.
[Curing condition B]
The epoxy resin composition is poured into a mold gap in which a spacer (silicone tube) with a thickness of 2 mm is sandwiched between glass plates, cured in an oven at 80 ° C. for 2 hours, and the cured product is removed from the mold to become tack-free. Then, after-curing was further performed at 160 ° C. for 2 hours to obtain a cured resin plate having a thickness of 2 mm.
[Curing conditions C]
The epoxy resin composition is poured into a gap of a mold in which a spacer (silicone tube) having a thickness of 2 mm is sandwiched between glass plates, cured in an oven at 25 ° C. for 24 hours, and the cured product is taken out of the mold and becomes tack-free. Then, after-curing was further performed at 120 ° C. for 2 hours to obtain a cured resin plate having a thickness of 2 mm.
3. Production of Carbon Fiber Reinforced Composite Material Carbon fiber fabric (carbon fiber: CO6343, cut out to 150 mm × 150 mm on a SUS plate coated with a 200 mm × 200 mm × 3.5 mm polytetrafluoroethylene / perfluoroalkyl vinyl ether copolymer. 4 sheets of a basis weight of 198 g / cm ² , manufactured by Toray Industries, Inc., cast the epoxy resin composition and impregnate the resin by pressing the resin with a roller, and another polytetrafluoroethylene / perfluoro A SUS plate coated with an alkyl vinyl ether copolymer was placed. This was after-cured in an oven at 100 ° C. for 1 hour and then at 170 ° C. for 1 hour to obtain a fiber-reinforced composite material having a thickness of 1.5 mm. Voids such as bubbles were not confirmed in the fiber-reinforced composite material obtained by visual confirmation. Using this as a test piece, various evaluation tests were performed. The results are shown in Table 1.

  For Comparative Example 4, the carbon fiber fabric was not sufficiently impregnated with the varnish, and the carbon fiber was exposed on the surface, and there were many bubbles on the surface of the resin part, and a test piece that could withstand the evaluation test was prepared. It could not be manufactured.

In addition, each component used for the epoxy resin composition of an Example and a comparative example is as follows.
“BPA liquid epoxy resin”: bisphenol A liquid epoxy resin, trade name “EPICLON 850S” manufactured by DIC Corporation, epoxy equivalent of 188 g / eq .
“ Vinyl ester resin”: bisphenol A type epoxy methacrylate (reaction product of “EPICLON 850S” with methacrylic acid)
“Polyglycidylamine”: N, N, N ′, N′-tetraglycidyldiaminodiphenylmethane (“ARLDITE MY721CH” manufactured by Huntsman Advanced Materials Co., Ltd.)
“HO-MS”: 3-[[2- (methacryloyloxy) ethoxy] carbonyl] propionic acid (“Light Ester HO-MS” manufactured by Kyoeisha Chemical Co., Ltd.)
“Radical polymerization initiator A”: 1,1-di (t-hexylperoxy) cyclohexane (polymerization initiator “Perhexa HC” manufactured by NOF Corporation)
“Radical polymerization initiator B”: Methyl ethyl ketone peroxide (“Permec N” manufactured by NOF Corporation)
“2E4MZ”: 2-ethyl-4-methylimidazole (Cureazole 2E4MZ manufactured by Shikoku Kasei Co., Ltd.)
“2MZ”: 2-methylimidazole (“Cureazole 2MZ” manufactured by Shikoku Kasei Co., Ltd.)
“6% cobalt naphthenate”: cobalt naphthenate solution (cobalt atom content 6 mass%, solvent: mineral spirit)
Further, “A”, “B”, and “C” in “curing conditions” in Table 1 correspond to the “curing conditions A”, “curing conditions B”, and “curing conditions C”, respectively.

Claims (9)

Epoxy equivalent is 500 g / eq. The following bisphenol type epoxy resin (A), the following structural formula (1)

(Wherein R ¹ is a saturated aliphatic hydrocarbon group having 2 to 10 carbon atoms, X is an ester bond or carbonate bond, R ² is a saturated aliphatic hydrocarbon group having 2 to 10 carbon atoms, or aromatic carbonization. Represents a hydrogen group, and n represents an integer of 1 to 5.)
The radical polymerization monomer (B) and the radical polymerization initiator (C) represented by the formula are essential components, and further, an unsaturated carboxylic acid or an anhydride thereof having a molecular weight of 160 or less. A resin composition for fiber-reinforced composite materials containing either a functional monomer (D), an aromatic vinyl compound or a (meth) acrylic ester (E), wherein the bisphenol-type epoxy resin (A) and epoxy group, Ri proportion der the equivalent ratio [epoxy groups / group] is 1 / 1-1 / 0.1 with the acid groups in the acid-group-containing radical polymerizable monomer (B), and the radical polymerization initiator (C) a fiber-reinforced composite material for a resin composition characterized that you contained in an amount of 0.01 to 5 parts by weight per the composition 100 wt. Fiber-reinforced composite material with the resin composition for fiber-reinforced composite material according to claim 1 Symbol placement, and reinforcing fibers as essential components. The fiber-reinforced composite material according to claim 2 , wherein the volume content of the reinforcing fibers is in the range of 40 to 85%. A cured product obtained by subjecting the fiber-reinforced composite material according to claim 2 or 3 to an in situ polymerization reaction. A fiber-reinforced resin molded article comprising a cured product of the resin composition for fiber-reinforced composite material according to claim 1 and reinforcing fibers as essential components. The fiber-reinforced resin molded article according to claim 5 , wherein the volume content of the reinforcing fibers is in the range of 40 to 85%. A substrate made of reinforcing fibers and placed in a mold, injecting claim 1 Symbol placement of the fiber-reinforced composite material resin composition is impregnated, and wherein the curing by situ polymerization reaction A method for producing a fiber-reinforced resin molded product. Reducing the pressure in the mold was placed a substrate composed of reinforcing fibers cavity, the fiber-reinforced composite material for the resin composition of claim 1 Symbol placement, by utilizing the pressure difference between the depressurized cavity pressure and external pressure The manufacturing method of the fiber reinforced resin molded product of Claim 7 using the vacuum RTM molding method which inject | pours in a cavity and impregnates the said base material. The fiber-reinforced resin molded article according to claim 5 or 6 , which is a member for automobiles.