JP2001302823A - Resin composition for fiber-reinforced composite material, prepreg and fiber-reinforced composite material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a resin composition for fiber-reinforced composite materials capable of imparting excellent mechanical characteristics to the composite material, a prepreg and the composite material having excellent mechanical characteristics. SOLUTION: This resin composition for fiber reinforced composite materials comprises 100 pts.wt. of (A) an aromatic epoxy resin, 2-15 pts.wt. of (B) an aliphatic epoxy resin and/or an alicyclic epoxy resin, 2-25 pts.wt. of (C) a phenoxy resin or a polyvinylformal resin and 5-12 pts.wt. of (D) an epoxy resin curing agent as essential ingredients.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a resin composition for a fiber-reinforced composite material, a prepreg, and a fiber-reinforced composite material.

[0002]

2. Description of the Related Art Fiber reinforced composite materials using carbon fiber, glass fiber or the like as a reinforcing material are used for sports and leisure goods such as golf shafts, fishing rods, tennis rackets, etc.
It is used for industrial materials such as printing ink rolls and pressure vessels, medical equipment, bridge repair, civil engineering repair, etc.

Further, in recent years, such fiber-reinforced composite materials have been increasingly used for sporting goods, particularly golf shafts.

[0004] Fiber reinforced composite materials such as reinforced fiber plastic (FRP) and carbon fiber reinforced plastic (CFRP) are prepared by impregnating a matrix resin into a reinforced fiber base material such as carbon fiber, glass fiber, aramid fiber and boron fiber. It is obtained by laminating these and curing at an appropriate temperature.

[0005] As a matrix resin of CFRP, an epoxy resin having excellent adhesion to carbon fibers is employed. In recent years, golf shafts have been diversified, lightweight shafts and long shafts have been developed, and the thicknesses of the shafts have been reduced along with them. Conventionally, bisphenol A type epoxy resins, which are mainly used, have low composite properties, especially low interlaminar shear strength (ILSS) and low elongation of the resin, so they are weak against deformation. The prepreg obtained has a drawback that the drapability is low.

On the other hand, a polyfunctional epoxy resin has a low inter-crosslinking density and thus has a high glass transition temperature, and therefore, the heat resistance, interlayer shear strength (ILSS) and bending strength of the obtained molded article are high. On the other hand, when a resin composition is produced, its reactivity is high, and thus there is a problem in the quality of the obtained resin composition and safety at the time of compounding. Further, when the polyfunctional epoxy resin is the main component, the cured resin becomes brittle, which is not preferable for sports use, especially for recent lightweight CFRP golf shafts.

However, in order to impart high bending strength and high interlayer shear strength to the fiber-reinforced composite material as described above, a polyfunctional epoxy resin such as a phenol novolak type epoxy resin and a glycidylamine type epoxy resin is replaced with a bisphenol type epoxy resin. Fiber reinforced composite materials manufactured using matrix resin mixed with resin have improved heat resistance compared to fiber reinforced composite materials with matrix resin made of bisphenol-type epoxy resin alone, There was a drawback that proof stress and impact resistance were significantly reduced.

[0008] As a means for improving the proof stress and impact resistance against large deformation, a thermoplastic resin such as polyether sulfone, nylon or the like or a rubber-modified resin is known. In this case, the viscosity of the resin increases, and the resin mixing process becomes very complicated. In addition, acrylic resin fine particles and butadiene fine particles are known as toughness improvers. However, when mixing the resin, air is mixed in, and a satisfactory resin for prepreg cannot be obtained.

A hollow pipe such as a golf shaft is
In general, features are obtained by variously changing the lamination structure depending on the application. When a pitch-based low-modulus carbon fiber (CF) is used as a part of the laminated structure, peeling may occur at the time of breakage, possibly due to a defect with a general-purpose prepreg.

Japanese Patent Application Laid-Open No. 9-268221 discloses a prepreg compound comprising a general-purpose epoxy resin and polyethylene glycol diglycidyl ether and / or polypropylene glycol diglycidyl ether. However, there is a problem in handleability and moldability of the prepreg. JP-A-60-
197723 discloses a fiber-reinforced composite material made of an epoxy resin containing polyethylene glycol having an amino group or a carboxyl group as an end group, which has a characteristic of vibration damping. Similarly, there is a problem in improving the bending strength.

[0011]

SUMMARY OF THE INVENTION The present invention overcomes the above-mentioned problems and combines an aromatic epoxy resin and an aliphatic epoxy resin so that cracks and peeling can occur even in the case of breakage due to large deformation. Stays in a local area, a resin composition for a fiber-reinforced composite material capable of providing a fiber-reinforced composite material having excellent moldability, a prepreg obtained by using the composition, and a fiber obtained by curing the prepreg. It is intended to provide a reinforced composite material.

[0012]

(1) The present invention relates to (A)
100 parts by weight of an aromatic epoxy resin, (B) an aliphatic epoxy resin and / or an alicyclic epoxy resin 2 to 15
Parts by weight, (C) 2 to 25 parts by weight of phenoxy resin or polyvinyl formal resin, (D) epoxy resin curing agent 5
The present invention relates to a resin composition for a fiber-reinforced composite material containing from about 12 parts by weight to about 12 parts by weight. (2) The present invention relates to a prepreg obtained by impregnating a reinforcing fiber with the resin composition for a fiber-reinforced composite material according to the above (1). (3) The present invention relates to a fiber-reinforced composite material obtained by curing the prepreg according to (2).

Hereinafter, the contents of the present invention will be described in more detail. Examples of the aromatic epoxy resin of the component (A) in the present invention include a bisphenol epoxy resin, a resorcinol epoxy resin, an aromatic amine epoxy resin, an aromatic glycidyl ester epoxy resin, a naphthalene epoxy resin, and a biphenyl epoxy resin. Resins and mixtures thereof can be used.

Further, two or more aromatic epoxy resins different in any one of viscosity at 25 ° C., epoxy equivalent and number average molecular weight can be used in combination.

Examples of the bisphenol type epoxy resin include bisphenol A type epoxy resin, bisphenol F type epoxy resin, phenol type epoxy resin and cresol type epoxy resin. Examples of the bisphenol A type epoxy resin are Epicoat 825, Epicoat 827, Epicoat 828, Epicoat 834, Epicoat 1002, Epicoat 1004, Epicoat 100
9 (each trade name, manufactured by Yuka Shell Epoxy), Epotote YD128, Epotote YD011, Epotote YD
012, Epototo YD014, Epotote YD01
7, Epototo YD019, Epototo YD020 (each trade name, manufactured by Toto Kasei Co., Ltd.), Epicron 840, Epicron 850, Epicron 855, Epicron 860, Epicron 1050, Epicron 3050, Epicron 4
050, Epicron 7050 (trade names, manufactured by Dainippon Ink and Chemicals, Inc.), DER330, DER331, DE
R332, DER662, DER662U, DER66
3U (trade names, manufactured by Dow Chemical Company), Araldite CY205, Araldite CY230, Araldite C
Y232, Araldite CY221, Araldite GY
257, Araldite GY252, Araldite GY2
55, Araldite GY250, Araldite GY26
0, Araldite GY280, Araldite GY607
1, Araldite GY7071, Araldite GY70
72 (each trade name, manufactured by Ciba Geigy).

Examples of bisphenol F type epoxy resins include Epicoat 806, Epicoat 807 (manufactured by Yuka Shell Epoxy), Epototo YDF170 (manufactured by Toto Kasei), and Epicron 830 (manufactured by Dainippon Ink and Chemicals, Inc.).
And the like that are commercially available under the trade names such as

The phenol type epoxy resin and the cresol type epoxy resin include Epicoat 152, Epicoat 154 (trade names, manufactured by Yuka Shell Epoxy Co., Ltd.), Epotote YDPN-638, Epotote YDCN70.
1. Epotote YDCN702, Epotote YDCN7
03 (each trade name, manufactured by Toto Kasei), DEN431, D
EN438 and DEN439 (trade names, manufactured by Dow Chemical Co., Ltd.) and the like.

As a resorcinol type epoxy resin, Denacol EX-201 (trade name, manufactured by Nagase Kasei Kogyo Co., Ltd.) is used. As a hydroquinone type epoxy resin, Denacol EX-201 is used.
203 (trade name, manufactured by Nagase Kasei Kogyo).

Examples of the aromatic amine type epoxy resin include:
Tetraglycidyldiaminodiphenylmethane, triglycidylaminophenol, diglycidylaniline, and diglycidylorthotoluidine are listed. Examples of commercially available tetraglycidyldiaminodiphenylmethane include Sumi-Epoxy ELM434 (trade name, manufactured by Sumitomo Chemical Co., Ltd.), Epototo YH434L, and Epototo YH434. (Trade name, manufactured by Toto Kasei Kogyo), Araldite MY720 (trade name,
Commercial products of triglycidyl aminophenol include Sumi-Epoxy ELM100 and Sumi-Epoxy.
Epoxy ELM120 (each trade name, manufactured by Sumitomo Chemical Co., Ltd.),
GAN (trade name, manufactured by Nippon Kayaku Co., Ltd.) as diglycidyl aniline, GOT as diglycidyl orthotoluidine
(Trade name, manufactured by Nippon Kayaku Co., Ltd.).

Examples of the aromatic glycidyl ester type epoxy resin include denacol EX-721 (trade name, manufactured by Nagase Kasei Kogyo Co., Ltd.) which is o-phthalic acid diglycidyl ester, and denacol EX-711 (which is a terephthalic acid diglycidyl ester). Product name, Nagase Kasei Kogyo Co., Ltd.), o
A which is a nuclear hydride of diglycidyl phthalate
K-601 (trade name, manufactured by Nippon Kayaku Co., Ltd.) and the like.

Examples of the naphthalene type epoxy resin include 1,
Epicron HP-4032H (trade name, manufactured by Dainippon Ink and Chemicals, Inc.), which is 6-dihydroxynaphthalenediglycidyl ether, and the like.

As the aromatic epoxy resin, 4,4 ′
Epicoat YX4000 (trade name, manufactured by Yuka Shell Epoxy Co.), which is dihydroxy-3,3 ', 5,5'-biphenyldiglycidyl ether; 4,4'-dihydroxy-3,3', 5,5'- Epicoat YL6121H (trade name, manufactured by Yuka Shell Epoxy Co., Ltd.), which is a mixture of biphenyl diglycidyl ether and 4,4′-dihydroxybiphenyl diglycidyl ether, and the like.

As the aromatic epoxy resin, a liquid epoxy resin and a solid epoxy resin at room temperature can be used. In the present invention, the liquid epoxy resin and the solid epoxy resin are mixed to obtain the resin composition. The viscosity can be adjusted.

The mixing ratio of the component (B) is preferably 2 to 15 parts by weight, more preferably 7 to 12 parts by weight.

When the amount of the component (B) is less than 2 parts by weight, no improvement in the physical properties of the molded article is exhibited when the prepreg impregnated with the resin composition is formed into a molded article. In this case, stickiness is too strong, causing a problem in workability, and the obtained molded article has a low glass transition temperature, which is not preferable.

As the aliphatic epoxy resin and / or alicyclic epoxy resin of the component (B), commercially available products such as polypropylene glycol diglycidyl ether Denacol EX-921, Denacol EX-931, and polytetramethylene glycol diglycidyl ether EX-922, which is neopentyl glycol diglycidyl ether; Denacol EX-212, which is 1,6-hexanediol diglycidyl ether (each trade name, manufactured by Nagase Kasei Kogyo Co., Ltd.); polyhydric alcohols Epicron 705, Epicron 707, Epicron 720, Epicron 725 (each trade name, manufactured by Dainippon Ink and Chemicals, Inc.) which are ether type epoxy resins, and Rica Resin HBE which is a hydride of bisphenol A type epoxy resin Trade name, manufactured by New Japan Chemical Co., Ltd.), RIKARESIN BEO-6 that adding ethylene oxide to bisphenol A type epoxy resin, further glycidylated
0E (trade name, manufactured by Shin Nippon Rika Co., Ltd.), lyciresin DME obtained by hydrogenating xylylene glycol and glycidylating it
100 (trade name, manufactured by Nippon Rika Co., Ltd.), bisphenol A
GL61, plaxel GL62, plaxel G101, plaxel G102, plaxel G10 in which caprolactone is added to the secondary hydroxyl group of the epoxy resin.
5, Praxel G401, Praxel G402 (each trade name, Daicel Chemical Industries Ltd.) and the like.

In the present invention, the compounding ratio of the component (C) used for adjusting the tack, adjusting the drape and adjusting the viscosity of the resin composition (resin composition) is preferably 2 to 25 parts by weight. Preferably it is 5 to 20 parts by weight.

When the amount of the component (C) is less than 2 parts by weight, the effects of tack adjustment, drape adjustment and viscosity adjustment of the resin composition are not observed. Is worse, and air bubbles easily remain in the resin, and the physical properties of the resin are deteriorated.

Examples of the phenoxy resin of the component (C) include phenothoto YP-50 and phenotote YP-70 (each trade name, manufactured by Toto Kasei Co., Ltd.), Epicoat 1256 (trade name, manufactured by Yuka Shell Epoxy Co., Ltd.), Sumi-Epoxy ESP
-50 (trade name, manufactured by Sumitomo Chemical Co., Ltd.), PKHH (trade name, manufactured by Phenoxy Associates) and the like. Examples of the polyvinyl formal resin include vinylek (trade name, manufactured by Chisso Corporation).

The mixing ratio of the component (D) used in the present invention is preferably 5 to 12 parts by weight, more preferably 7 to 11 parts by weight. When the amount of the component (D) is less than 5 parts by weight, when molding into a composite material, the curing of the resin is delayed, and it takes a long time to mold, and the obtained cured product (composite material) has a low glass transition temperature. And excellent mechanical properties cannot be obtained. If the amount exceeds 12 parts by weight, the resin hardens too quickly during molding into a composite material, and it is difficult to obtain a molded product stably.

As an example of the epoxy resin curing agent of the component (D), dicyandiamide alone or dicyandiamide and a curing accelerator such as 3- (3,4-dichlorophenyl)-
1,1-dimethylurea, 3- (4-chlorophenyl)
One in which a derivative such as -1,1-dimethylurea or 3-phenyl-1,1-dimethylreare is used in combination.

[0032] In addition to the curing agent of component (D), other curing agents and curing accelerators can be further compounded, if necessary. Examples of curing agents that can be further compounded in addition to the component (D) include diaminodiphenylsulfone and diaminodiethylbenzene, and examples of the curing accelerator that can be further compounded in addition to the component (D) include boron trifluoride monoethylamine complex and boron trichloride monoethylamine. And the like, boron trifluoride complexes and boron trichloride complexes.

In the resin composition for a fiber-reinforced composite material (epoxy resin composition) of the present invention, other epoxy resins, toughness-imparting resins, fillers, coloring agents and the like can be blended as long as the performance is not impaired. .

The toughness-imparting resin which can be optionally contained in the resin composition of the present invention includes a reactive elastomer, a Hiker CTBN-modified epoxy resin, a urethane-modified epoxy resin, a nitrile rubber-added epoxy resin, and a crosslinked acrylic rubber fine particle. Examples of the epoxy resin include an added epoxy resin, a silicone-modified epoxy resin, and a thermoplastic elastomer-added epoxy resin.

The filler which can be optionally contained in the resin composition of the present invention includes mica, alumina,
Talc, finely divided silica, wollastonite, sepiolite, basic magnesium sulfate, calcium carbonate, polytetrafluoroethylene powder, zinc powder, aluminum powder,
Organic fine particles, that is, acrylic fine particles, epoxy resin fine particles, polyamide fine particles, polyurethane fine particles, and the like can be used.

The coloring agent which can be optionally contained in the resin composition of the present invention includes inorganic pigments such as organic pigments such as azo pigments, phthalocyanine pigments, quinacridone pigments and anthraquinone pigments. Titanium, graphite, cobalt violet, red iron, carbon black, and the like.

The method for producing the resin composition according to the present invention is not particularly limited. For example, the resin components (A) and (B) are heated and mixed at 160 to 200 ° C., and then cooled to 140 ° C. or less by cooling or natural heat radiation. After the temperature is lowered, a method of adding the component (C) and then adding the hardening component (D) after the resin temperature becomes 85 ° C. or lower is preferably used. When the components (C) and (D) are mixed, a method of mixing by vacuum degassing with stirring for the purpose of reducing generation of voids after molding is preferably adopted. According to this method, the components (C) and (D) are uniformly dispersed in the resin composition, and the composition and the prepreg have excellent storage stability. When the curing component (D) is added and mixed at a temperature where the resin temperature is higher than 90 ° C., a part of the curing component (D) is dissolved in the resin, and the resin and the curing agent easily react with each other. The storage stability of a prepreg formed by impregnating reinforced fibers with reinforced fibers is significantly impaired.

In the present invention, the above-mentioned component (A),
A prepreg is obtained by impregnating a reinforcing fiber with a resin composition containing (B), (C) and (D).

The reinforcing fibers are not particularly limited, and all fibers generally used as reinforcing fibers of a fiber-reinforced composite material can be used. For example, carbon fiber, glass fiber, aramid fiber, boron fiber, silicon carbide fiber, and organic fiber subjected to surface treatment (ozone treatment, plasma treatment),
Alternatively, a fiber having a hybrid structure of two or more selected from these can be used.
When carbon fiber is used as the reinforcing fiber, a lightweight and highly rigid composite material molded article can be obtained, so that it is preferably used.

The form of the reinforcing fiber prepreg is not particularly limited, and can be appropriately selected according to the purpose. For example,
One-way prepregs, woven prepregs, braided woven prepregs, nonwoven prepregs, and the like can be given.

The method for impregnating the reinforcing fiber with the resin composition in the present invention is not particularly limited, and a so-called hot melt method, in which the resin composition is usually heated to 60 to 90 ° C. to impregnate the reinforcing fiber, is used. It is preferably adopted.

The content of the resin composition of the prepreg thus produced is usually 20 to 50% by mass, preferably 25 to 45% by mass based on the total amount of the reinforcing fibers and the resin composition.
It is.

The prepreg is finally formed into a fiber reinforced composite material. For example, prepregs are laminated, and usually in an autoclave or a pressure press or the like, usually at 110 to 150 ° C.
By heating and curing for 30 minutes to 3 hours, a fiber-reinforced composite material can be obtained. The obtained fiber-reinforced composite material has stable quality, is uniform and has few voids, even though the curing agent component (D) is a dispersion system.

Examples of uses of the composite material include golf shafts, tennis rackets, ski poles, rolls for printing ink, bicycle pipes, pressure vessels, conveying members, and the like. Among them, the fiber reinforced composite material of the present invention is suitable for a golf shaft. That is, in recent years, the weight of golf shafts has been reduced, and the conditions of use have become severe,
It is becoming difficult for conventional shafts to satisfy both weight reduction and excellent impact resistance.

The golf shaft obtained by the present invention is lighter than conventional golf shafts and can withstand severe use conditions.

[0046]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the invention is limited thereto. The test methods employed in the examples and comparative examples are as follows. (Long span bending test) A long pipe three-point bending test was performed on a straight pipe test piece using Tensilon, a universal testing machine manufactured by Orientec Co., Ltd. The test pieces were 10 mm in inner diameter, 1200 mm long, and the distance between supports (span) was 600 mm.

Example 1-8 and Comparative Example 1-8 An epoxy resin composition having the composition shown in Tables 1 and 2 was prepared.
A resin composition is impregnated into each of low-modulus carbon fibers (CF) (trade name: XN-05, XN-10) manufactured by Nippon Graphite Fiber Co., Ltd. and general-purpose CF (trade name: T700S) manufactured by Toray Industries, Inc. Unidirectional prepreg (Fiber weight 10
0 g, resin content 33%).

To a core metal having an inner diameter of 10 mmφ, a general-purpose prepreg P3052S-12 (trade name) (T70) manufactured by Toray Industries, Inc.
0S / fiber basis weight 125g / resin content 33%) are wound in two layers each such that the carbon fibers are oriented in the ± 45 ° direction with respect to the axial direction of the cored bar. 1 so that it faces 0 ° direction (axial direction)
Layer wrapped. Furthermore, from above, a general-purpose prepreg P3052S-12 (T700S / fibre weight 1) manufactured by Toray Industries, Inc.
25 g / resin content of 33%) is wound in two layers so that the carbon fibers are oriented in the 0 ° direction (axial direction).
A uniaxially stretched tape of P (polypropylene) was wound, and the obtained laminate was cured by heating at 130 ° C. for 1 hour in a drying furnace. The obtained molded pipe was cut out to a length of 1200 mm to obtain a test piece. A long span three-point bending test was performed on the obtained pipe test piece.

[0049]

[Table 1]

[0050]

[Table 2] The numerical unit of each component in the table is parts by weight. As is clear from Table 1, the prepreg using an aliphatic epoxy resin or an alicyclic epoxy resin has a high load at break in long span bending due to high elongation and toughness of the resin, and energy due to deflection at break. , The peeling between the layers of the prepreg was hardly observed after the fracture.

On the other hand, in a prepreg which does not use an aliphatic epoxy resin or an alicyclic epoxy resin as in the comparative example of Table 2, the elongation and toughness of the resin are insufficient, so that the load at break in long span bending is low. Further, since the energy due to the bending at the time of breaking cannot be completely absorbed, large peeling occurred between the layers of the prepreg after the breaking. In addition, when the component (C) was not used, there was a problem in handleability (tack, drape) and moldability of the prepreg.

[0052]

As described above, the resin composition of the present invention cannot be achieved by the conventional epoxy resin for prepreg.
The prepreg obtained by impregnating the reinforcing fiber with the resin composition provides handleability, particularly suitable drapeability, and the cured product (composite material) obtained using the composition of the present invention has excellent mechanical properties. That is, a composite material having excellent resistance to large deformation can be obtained.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08L 71:10) C08L 71:10) (C08L 63/00 (C08L 63/00 29:14) 29:14 (72) Inventor Yoshihiro Harada 8 Chidori-cho, Naka-ku, Yokohama-shi, Kanagawa Prefecture F-term in the Central Research Laboratory, Nishiishi Mitsui Co., Ltd. 4F072 AA02 AA07 AB06 AB08 AB09 AB10 AD03 AD08 AD25 AD26 AD27 AD42 AE01 AH21 AL04 AL05 4J002 BE063 CD012 CD022 CD041 CD051 CD061 CD101 CD131 CH083 CL064 DA017 DJ007 DK007 DL007 ER026 FA044 FA047 FD010 FD014 FD017 FD140 FD146 FD150 GC00 4J036 AA02 AA05 AA06 AJ05 AJ08 DA01 FB01FB12

Claims (3)

[Claims] (A) 100 parts by weight of an aromatic epoxy resin, (B) 2 to 15 parts by weight of an aliphatic epoxy resin and / or an alicyclic epoxy resin, (C) 2 to 2 parts of a phenoxy resin or a polyvinyl formal resin. 25 parts by weight, (D)
A resin composition for a fiber-reinforced composite material containing 5 to 12 parts by weight of an epoxy resin curing agent as an essential component. 2. A prepreg obtained by impregnating a reinforcing fiber with the resin composition for a fiber-reinforced composite material according to claim 1. 3. A fiber-reinforced composite material obtained by curing the prepreg according to claim 2.