JP6198568B2 - Prepreg, fiber reinforced epoxy resin molded body, and tubular body made of fiber reinforced epoxy resin material - Google Patents

Description

  The present invention relates to a prepreg containing an epoxy resin composition and reinforcing fibers, and more particularly, to improvement in strength of a fiber-reinforced epoxy resin molded article obtained using the prepreg.

Tubular bodies made of fiber-reinforced epoxy resin material are used for golf club shafts and fishing rods, and prepregs are used for manufacturing such tubular bodies. For example, Patent Document 1 includes a reinforced fiber aligned in one direction and an epoxy resin composition, and has a tensile elastic modulus E (GPa) of the reinforced fiber and a fiber reinforced obtained by heat curing. A prepreg sheet is disclosed in which the composite material has a 6-degree compressive strength σ (MPa) satisfying the following expressions (1) and (2).
200 GPa ≦ E ≦ 950 GPa (1)
−3.6E + 2000 ≦ σ ≦ −3.6E + 2600 (2)

In Patent Document 2, an epoxy resin composition comprising a reinforcing fiber having a tensile modulus of 200 to 800 GPa, a curing agent, and the following constituent element [A] and / or constituent element [B] is used as a constituent element. A shaft for a golf club using a fiber reinforced composite material, wherein the tensile modulus of the cured product of the epoxy resin composition is 3.4 to 4.4 GPa, and wet cutting of the fiber reinforced composite material A prepreg used for manufacturing a golf club shaft having a cutting amount of 3% by weight or less is disclosed (see paragraph [0089]).
[A] a compound having one functional group capable of reacting with an epoxy resin or a curing agent and one or more amide bonds in the molecule;
[B] Polyester polyurethane having an aromatic ring in the molecule

Patent Document 3 discloses a cured product of an epoxy resin composition in which a matrix resin is composed of the following components [A], [B], and [C] in a fiber reinforced plastic tubular body composed of a reinforced fiber and a matrix resin. A prepreg used for the production of a fiber-reinforced plastic tubular body characterized by the above is disclosed (see paragraph [0083] etc.).
[A] An epoxy resin containing 70 parts by weight or more of a bifunctional epoxy resin in 100 parts by weight of an epoxy resin,
[B] Fine particles containing a rubber phase and substantially insoluble in an epoxy resin,
[C] Curing agent

Patent Document 4 discloses a prepreg obtained by impregnating a reinforcing fiber with a cured product of an epoxy resin composition for a fiber-reinforced composite material containing at least the following components [A], [B] and [C]. (Refer to [Claim 11]).
[A] Epoxy resin containing 70 parts by weight or more of bifunctional epoxy resin in 100 parts by weight of epoxy resin [B] Polyester-based or polyamide-based thermoplastic elastomer [C] Curing agent or blend of curing agent and curing accelerator

JP 2003-103519 A JP 2001-54602 A JP-A-9-85844 JP-A-8-337707

  With the improvement in performance and quality of golf clubs and fishing rods, the strength of the tubular body made of the above-described fiber-reinforced composite material has become insufficient. Particularly in recent years, in order to control the position of the center of gravity of the tubular body, the size of the flexure, etc., the tubular body is provided with a thin-walled portion, so that higher strength is required for the fiber reinforced composite material. In addition, prepregs are required to have good tackiness and draping properties. However, when a low molecular weight epoxy resin is used as the resin component and the viscosity of the resin component is lowered, the strength of the resulting fiber-reinforced composite molded product is reduced. To do. The present invention has been made in view of the above circumstances, and has an object to provide a prepreg from which a tubular body made of a fiber-reinforced epoxy resin material having excellent tackiness and drapeability and excellent strength can be obtained. And

  The prepreg of the present invention is a prepreg containing an epoxy resin composition and reinforcing fibers, and the epoxy resin composition includes, as an epoxy resin component, a novolac type epoxy resin, a bisphenol A type epoxy resin, and a bisphenol F type epoxy resin. The content ratio of the novolac type epoxy resin in the entire epoxy resin component is 2% by mass to 19% by mass, and the mass ratio of the bisphenol A type epoxy resin and the bisphenol F type epoxy resin in the epoxy resin component (bisphenol) A type epoxy resin / bisphenol F type epoxy resin) is 0.3 to 3.0, and the epoxy equivalent (g / eq) of the entire epoxy resin component is 200 to 400, and the epoxy resin composition is cured. The product has a swelling rate of 20% by mass to 44% in methyl ethyl ketone. Characterized in that it is a%.

  As epoxy resin component, it contains novolac type epoxy resin, bisphenol A type epoxy resin and bisphenol F type epoxy resin, and by controlling these contents, the prepreg tack and drape properties are improved The toughness and strength of the cured product of the resin composition can be improved. The swelling ratio with the methyl ethyl ketone is an index of the crosslinking density of the epoxy resin composition. A cured product of the epoxy resin composition having a swelling rate with methyl ethyl ketone falling within the above range has an appropriate elongation and excellent adhesion to reinforcing fibers. As a result, the fiber-reinforced epoxy resin molded product obtained from the prepreg of the present invention has an improved interfacial strength between the reinforcing fiber and the matrix resin, and the effect of compounding with the reinforcing fiber is increased. The mechanical strength is further improved.

  The epoxy resin composition preferably contains dicyandiamide as a curing agent and a urea derivative as a curing accelerator. As said hardening | curing agent, it is preferable to contain 13-40 g of dicyandiamide with respect to 1 mol of epoxy groups of an epoxy resin component. It is preferable that the said epoxy resin composition contains 2 mass parts-12 mass parts of thermoplastic resins further with respect to 100 mass parts of epoxy resin components. As the thermoplastic resin, polyvinyl formal is suitable.

The epoxy resin composition preferably has a content of the reinforcing fiber of 65% by mass to 85% by mass. The reinforcing fibers are preferably carbon fibers. Tensile modulus of the reinforcing fibers ^is preferably ^{10tf / mm 2 ~70tf / mm 2} .

  The present invention also includes a fiber reinforced epoxy resin molded body obtained by curing the epoxy resin composition contained in the prepreg, and a tubular body made of a fiber reinforced epoxy resin material formed using the prepreg. As the tubular body, a plurality of prepregs are laminated and the resin composition contained in the prepreg is cured, and the outermost prepreg located on the outermost side is the prepreg of the present invention, and the inner side of the outermost prepreg. It is preferable that at least one prepreg positioned is a prepreg having a density lower than that of the outermost prepreg. The present invention also includes a golf club shaft made of a tubular body made of this fiber-reinforced epoxy resin material.

  When the prepreg of the present invention is used, a tubular body made of a fiber-reinforced epoxy resin material having excellent bending strength can be obtained. Moreover, if the prepreg of this invention is used, the tubular body made from the fiber reinforced epoxy resin material which was excellent in bending strength and reduced in weight will be obtained.

It is explanatory drawing explaining the aspect of a tension test. It is explanatory drawing explaining the aspect of a bending test. It is a figure which shows the lamination | stacking aspect of the fiber reinforced prepreg which comprises the tubular body made from a fiber reinforced epoxy resin material. It is explanatory drawing explaining the bonding aspect of a prepreg.

  The prepreg of the present invention is a prepreg containing an epoxy resin composition and reinforcing fibers, and the epoxy resin composition includes, as an epoxy resin component, a novolac type epoxy resin, a bisphenol A type epoxy resin, and a bisphenol F type epoxy resin. The content ratio of the novolac type epoxy resin in the entire epoxy resin component is 2% by mass to 19% by mass, and the mass ratio of the bisphenol A type epoxy resin and the bisphenol F type epoxy resin in the epoxy resin component (Bisphenol A type epoxy resin / bisphenol F type epoxy resin) is 0.3 to 3.0, epoxy equivalent (g / eq) of the whole epoxy resin component is 200 to 400, and the epoxy resin composition The cured product has a swelling rate of 20% by mass with methyl ethyl ketone. Characterized in that it is a 4% by weight. The prepreg is a molding intermediate material obtained by impregnating a reinforcing fiber with an epoxy resin composition, and the epoxy resin composition is in an uncured or semi-cured state.

  In the present invention, novolac type epoxy resin, bisphenol A type epoxy resin and bisphenol F type epoxy resin are used as the epoxy resin component, and the content of novolac type epoxy resin, and bisphenol A type epoxy resin and bisphenol F type are used. The mass ratio with the epoxy resin is controlled. As a result, the viscosity of the epoxy resin composition can be reduced to improve the tackiness and draping properties of the prepreg, and the toughness and strength of the cured product of the epoxy resin composition can be improved and formed using this prepreg. The strength of the molded fiber reinforced epoxy resin is improved. Further, the swelling ratio with the methyl ethyl ketone indicates the crosslink density of the epoxy resin composition. A cured product of the epoxy resin composition having a swelling rate with methyl ethyl ketone falling within the above range has an appropriate elongation and excellent adhesion to reinforcing fibers. As a result, the fiber-reinforced epoxy resin molded product obtained from the prepreg of the present invention has an improved interfacial strength between the reinforcing fiber and the matrix resin, and the effect of compounding with the reinforcing fiber is increased. The mechanical strength is further improved.

  The epoxy resin composition used in the present invention will be described. The epoxy resin composition contains a novolac type epoxy resin, a bisphenol A type epoxy resin and a bisphenol F type epoxy resin as an epoxy resin component.

  The novolac type epoxy resin is a polyfunctional epoxy resin having more than 2 (preferably 3 or more) epoxy groups in the molecule. By containing the novolac type epoxy resin, the crosslink density of the cured product of the epoxy resin composition can be controlled. It is considered that the interfacial strength between the reinforcing fiber and the epoxy resin is improved by controlling the crosslinking density and setting the elongation of the cured product of the epoxy resin composition within an appropriate range. Although it does not specifically limit as said novolak-type epoxy resin, A phenol novolak-type epoxy resin, o-cresol novolak-type epoxy resin, etc. can be mentioned.

  The content of the novolac-type epoxy resin in the total epoxy resin component contained in the epoxy resin composition is 2% by mass or more, preferably 5% by mass or more, more preferably 7% by mass or more, preferably 19% by mass or less, preferably Is 15% by mass or less, more preferably 10% by mass or less. If the content of the novolac type epoxy resin is 2% by mass or more, the crosslink density is increased and the strength of the cured product of the resin composition is further improved, and if it is 19% by mass or less, the elongation of the cured product of the resin composition is increased. Is maintained, the interfacial strength with the reinforcing fiber is increased, and the strength of the fiber-reinforced epoxy resin molded body is further improved.

  The epoxy equivalent (g / eq) of the novolak type epoxy resin is preferably 50 or more, more preferably 75 or more, further preferably 100 or more, preferably 500 or less, more preferably 400 or less, and further preferably 300 or less. When the epoxy equivalent of the novolak type epoxy resin is within the above range, a crosslinked structure can be effectively formed.

  As commercially available products of phenol novolac type epoxy resins, jER (registered trademark) 152, jER154 (above, manufactured by Mitsubishi Chemical Corporation), EPICLON (registered trademark) N-740, EPICLON N-770, EPICLON N-775 (above, DIC Corporation), PY307, EPN1179, EPN1180 (above, Huntsman Advanced Material Co., Ltd.), YDPN638, YDPN638P (above, Toto Kasei Co., Ltd.), DEN431, DEN438, DEN439 (above, Dow Chemical Co., Ltd.) ), EPR600 (manufactured by Bakelite), EPPN-201 (manufactured by Nippon Kayaku Co., Ltd.), and the like.

  The epoxy resin composition contains a bisphenol A type epoxy resin and a bisphenol F type epoxy resin. The mass ratio of the bisphenol A type epoxy resin to the bisphenol F type epoxy resin (bisphenol A type epoxy resin / bisphenol F type epoxy resin) in the epoxy resin composition is 0.3 or more, preferably 0.4 or more. Preferably it is 0.5 or more, 3.0 or less, preferably 2.5 or less, more preferably 2.0 or less. If the mass ratio is within the above range, the tackiness of the prepreg can be improved while maintaining the strength and toughness of the cured product of the epoxy resin composition. When the mass ratio is less than 0.3, the strength of the cured product of the epoxy resin composition is increased, but the toughness is decreased, and when it exceeds 3.0, the elongation of the cured product is improved, but the strength is decreased.

  As for the bisphenol A type epoxy resin and the bisphenol F type epoxy resin, it is preferable to use one that is liquid at room temperature (25 ° C.) and the other that is solid at room temperature. As such an embodiment, for example, an embodiment using a bisphenol A type epoxy resin that is liquid at room temperature and a bisphenol F type epoxy resin that is solid at room temperature; a bisphenol A type epoxy resin that is solid at room temperature and a liquid at room temperature Of using a bisphenol F type epoxy resin that is liquid at room temperature, a mode of using a bisphenol A type epoxy resin that is solid at room temperature, and a bisphenol F type epoxy resin that is liquid at room temperature; Examples include using a liquid bisphenol A type epoxy resin, a bisphenol F type epoxy resin that is liquid at normal temperature, and a bisphenol F type epoxy resin that is solid at normal temperature. Among these, an embodiment using a bisphenol F type epoxy resin that is solid at room temperature is preferable.

  The viscosity (25 ° C.) of the liquid bisphenol A type epoxy resin at normal temperature is preferably 60 P or more, more preferably 75 P or more, further preferably 90 P or more, preferably 300 P or less, more preferably 250 P or less, Preferably it is 200 P or less. The viscosity of the epoxy resin can be measured with a viscoelasticity measuring device (manufactured by Anton Paar, “MCR301”, applied torque 6 mN · m). The epoxy equivalent (g / eq) of the liquid bisphenol A type epoxy resin at normal temperature is preferably 170 or more, more preferably 175 or more, further preferably 180 or more, preferably 300 or less, more preferably 290 or less. More preferably, it is 280 or less.

  The epoxy equivalent (g / eq) of the bisphenol A type epoxy resin that is solid at room temperature is preferably 300 or more, more preferably 350 or more, still more preferably 400 or more, preferably 20000 or less, more preferably 18000 or less. More preferably, it is 16000 or less.

  Examples of bisphenol A type epoxy resins that are liquid at room temperature include, for example, jER (registered trademark) 827, jER828, jER828EL, jER828XA, jER834 (manufactured by Mitsubishi Chemical Corporation), Epototo (registered trademark) YD-115, Epototo YD- 115G, Epotot YD-115CA, Epotot YD-118T, Epotot YD-127, Epotot YD-128, Epotot YD-128G, Epotot YD-128S (above, manufactured by Toto Kasei), EPICLON (registered trademark) 840, EPICLON 840-S , EPICLON 850, EPICLON 850-S (manufactured by DIC).

  Examples of the bisphenol A type epoxy resin that is solid at normal temperature include, for example, jER1001, jER1002, jER1003, jER1003F, jER1004, jER1004FS, jER1004F, jER1004AF, jER1055, jER1005F, jER1006FS, jER1007FS, jER1008FS, ER1008 Epototo YD-011, Epototo YD-012, Epototo YD-013, Epototo YD-014, Epototo YD-017, Epototo YD-019, Epototo YD-020N, Epototo YD-020H (manufactured by Toto Kasei) , EPICLON 1050, EPICLON 3050, EPICLON 4050, EPICLON 7050 (above, IC Co., Ltd.) and the like.

  The viscosity (25 ° C.) of the liquid bisphenol F type epoxy resin at normal temperature is preferably 9P or more, more preferably 12P or more, further preferably 15P or more, preferably 300P or less, more preferably 250P or less, Preferably it is 200 P or less. The epoxy equivalent (g / eq) of the liquid bisphenol F type epoxy resin at normal temperature is preferably 150 or more, more preferably 155 or more, further preferably 160 or more, preferably 300 or less, more preferably 290 or less. More preferably, it is 280 or less.

  The epoxy equivalent (g / eq) of the bisphenol F type epoxy resin that is solid at normal temperature is preferably 300 or more, more preferably 350 or more, still more preferably 400 or more, preferably 20000 or less, more preferably 18000 or less. More preferably, it is 16000 or less.

  Examples of the bisphenol F type epoxy resin that is liquid at room temperature include jER806, jER807 (above, manufactured by Mitsubishi Chemical Corporation), EPICLON830, EPICLON830-S, EPICLON835 (above, made by DIC). Examples of the bisphenol A type epoxy resin that is solid at room temperature include jER4005P, jER4007P, and jER4010P (manufactured by Mitsubishi Chemical Corporation).

  The epoxy resin composition may contain only the novolac type epoxy resin, bisphenol A type epoxy resin, and bisphenol F type epoxy resin as an epoxy resin component, and in addition to these, two epoxy compounds in the molecule. You may further contain the epoxy resin which has group, ie, a bifunctional epoxy resin. Specific examples of the bifunctional epoxy resin include hydrogenated bisphenol A type epoxy resin, hydrogenated bisphenol F type epoxy resin, bisphenol S type epoxy resin, tetrabromobisphenol A type epoxy resin, and bisphenol AD type epoxy. Examples thereof include bisphenol type epoxy resins such as resins. The bisphenol type epoxy resins may be used alone or in admixture of two or more. The amount of these bisphenol-type epoxy resins used is preferably 97% by mass or less, more preferably 96% by mass or less, and still more preferably 95% by mass or less in the epoxy resin component.

  200 or more are preferable, as for the epoxy equivalent (g / eq) of the whole epoxy resin component contained in the said epoxy resin composition, 250 or more are more preferable, 400 or less are preferable and 350 or less are more preferable. If the epoxy equivalent of the entire epoxy resin component is less than 200, the epoxy resin component becomes liquid at room temperature, and it may be difficult to produce or mold the prepreg. On the other hand, when the epoxy equivalent exceeds 400, the epoxy resin component becomes solid at room temperature, and it becomes difficult to mold the prepreg.

  The epoxy resin composition used in the present invention preferably contains a curing agent. Examples of the curing agent include dicyandiamide; active hydrogen such as 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenylsulfone, 3,3′-diaminodiphenylsulfone, m-phenylenediamine, and m-xylylenediamine. Aromatic amines having; active amines such as diethylenetriamine, triethylenetetramine, isophoronediamine, bis (aminomethyl) norbornane, bis (4-aminocyclohexyl) methane, dimer acid ester of polyethyleneimine; these activities Modified amines obtained by reacting hydrogen-containing amines with compounds such as epoxy compounds, acrylonitrile, phenol and formaldehyde, thiourea; dimethylaniline, triethylenediamine, dimethylbenzylamine, 2, Tertiary amines having no active hydrogen such as 1,6-tris (dimethylaminomethyl) phenol; imidazoles such as 2-methylimidazole and 2-ethyl-4-methylimidazole; polyamide resin; hexahydrophthalic anhydride, Carboxylic anhydrides such as tetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, methyl nadic anhydride, polycarboxylic acid hydrazides such as adipic hydrazide and naphthalenedicarboxylic hydrazide; polyphenol compounds such as novolac resins; Polymercaptans such as esters of thioglycolic acid and polyols; Lewis acid complexes such as boron trifluoride ethylamine complexes can be used. Among these, it is preferable to use dicyandiamide as a curing agent.

  The amount of the dicyandiamide added is preferably 13 g or more, more preferably 15 g or more, still more preferably 17 g or more, preferably 40 g or less, preferably 38 g or less, and more preferably 35 g or less with respect to 1 mol of the epoxy group of the epoxy resin component. preferable. If the addition amount of dicyandiamide is 13 g or more, the curing reaction further proceeds and the strength is further improved, and if it is 40 g or less, the elongation of the cured product of the resin composition is maintained and the interfacial strength with the reinforcing fiber is high. Thus, the strength of the fiber-reinforced epoxy resin molded body is further improved.

  An appropriate curing accelerator can be combined with the curing agent to increase the curing activity. As the curing accelerator, a urea derivative in which at least one hydrogen bonded to urea is substituted with a hydrocarbon group is preferable. The hydrocarbon group may be further substituted with, for example, a halogen atom, a nitro group, or an alkoxy group. Examples of the urea derivative include 3-phenyl-1,1-dimethylurea, 3- (parachlorophenyl) -1,1-dimethylurea, 3- (3,4-dichlorophenyl) -1,1-dimethylurea, 3- (Orthomethylphenyl) -1,1-dimethylurea, 3- (paramethylphenyl) -1,1-dimethylurea, 3- (methoxyphenyl) -1,1-dimethylurea, 3- (nitrophenyl) Derivatives of monourea compounds such as -1,1-dimethylurea; and N, N-phenylene-bis (N ′, N′-dimethylurea), N, N- (4-methyl-1,3-phenylene) -Derivatives of bisurea compounds such as bis (N ', N'-dimethylurea). Examples of preferred combinations include dicyandiamide, 3-phenyl-1,1-dimethylurea, 3- (3,4-dichlorophenyl) -1,1-dimethylurea (DCMU), 3- (3-chloro-4- Examples include combining urea derivatives such as methylphenyl) -1,1-dimethylurea and 2,4-bis (3,3-dimethylureido) toluene as curing aids. Among these, it is more preferable to combine dicyandiamide with 3- (3,4-dichlorophenyl) -1,1-dimethylurea (DCMU) as a curing accelerator.

  In the present invention, it is particularly preferable to use dicyandiamide (DICY) as a curing agent and a urea derivative as a curing aid. In this case, the content ratio of dicyandiamide (DICY) and the urea derivative is preferably 1.0 or more, more preferably 1.2 or more, and more preferably 1.5 or more in terms of mass ratio (DICY / urea derivative). 0 or less is preferable, 2.8 or less is more preferable, and 2.5 or less is more preferable. The mass ratio (DICY / urea derivative) is most preferably 2. If the mass ratio of DICY / urea derivative is within the above range, the curing rate is fast and the cured product has good physical properties.

  The epoxy resin composition may further contain other components such as oligomers, polymer compounds, organic or inorganic particles.

  As an oligomer that can be blended in the epoxy resin composition used in the present invention, a polyester polyurethane having a polyester skeleton and a polyurethane skeleton, a urethane having a polyester skeleton and a polyurethane skeleton, and further having a (meth) acrylate group at the molecular chain terminal (meta) ) Acrylates, indene oligomers and the like.

  A thermoplastic resin is suitably used as the polymer compound that can be blended in the epoxy resin composition used in the present invention. By blending a thermoplastic resin, the effect of controlling the viscosity of the resin, the handling property of the prepreg sheet, or improving the adhesiveness is preferably increased.

  Examples of the thermoplastic resin include polyvinyl acetal resin such as polyvinyl formal and polyvinyl butyral, polyvinyl alcohol, phenoxy resin, thermoplastic resin having an amide bond, polyamide, polyimide, thermoplastic resin having a sulfonyl group, Examples include polysulfone. Polyamide, polyimide and polysulfone may have a functional group such as an ether bond and a carbonyl group in the main chain. The polyamide may have a substituent on the nitrogen atom of the amide group. The epoxy resin composition used in the present invention preferably contains polyvinyl formal as a thermoplastic resin. If polyvinyl formal is contained, the toughness and elongation of the cured product are further improved.

  As content of the said thermoplastic resin, 2 mass parts or more are preferable with respect to 100 mass parts of epoxy resin components, 3 mass parts or more are more preferable, 4 mass parts or more are more preferable, 12 mass parts or less are preferable, 8 parts by mass or less is more preferable. If content of a thermoplastic resin is 2 mass parts or more, the elongation of an epoxy resin composition will become good and a tack | tuck can be provided. On the other hand, when the content of the thermoplastic resin exceeds 12 parts by mass, the epoxy resin composition may be solidified at room temperature. Therefore, the impregnation property to the reinforcing fiber is lowered, and a void may be caused at the time of producing the prepreg.

  As the organic particles that can be blended in the epoxy resin composition used in the present invention, rubber particles and thermoplastic resin particles are used. These particles have the effect of improving the toughness of the resin and improving the impact resistance of the fiber-reinforced composite material. Further, as rubber particles, cross-linked rubber particles and core-shell rubber particles obtained by graft polymerization of a different polymer on the surface of the cross-linked rubber particles are preferably used.

  As commercially available crosslinked rubber particles, XER-91 (manufactured by Nippon Synthetic Rubber Industry) comprising a crosslinked product of a carboxyl-modified butadiene-acrylonitrile copolymer, CX-MN series (manufactured by Nippon Shokubai Co., Ltd.) comprising acrylic rubber fine particles, YR-500 series (manufactured by Toto Kasei Co., Ltd.) or the like can be used. Commercially available core-shell rubber particles include paraloid EXL-2655 (manufactured by Kureha Chemical Co., Ltd.) made of butadiene / alkyl methacrylate / styrene copolymer, staphyloid AC-3355 made of acrylic ester / methacrylic ester copolymer, TR-2122 (manufactured by Takeda Pharmaceutical Co., Ltd.), PARALOIDEXL-2611, EXL-3387 (registered trademark, trade name, manufactured by Rohm & Haas) made of butyl acrylate / methyl methacrylate copolymer can be used. .

  As the thermoplastic resin particles, polyamide or polyimide particles are preferably used. As a commercially available polyamide particle, the Toray company make, brand name: SP-500, the ATOCHEM company make, Orgasol (trademark), etc. can be used.

  As inorganic particles that can be blended in the epoxy resin composition, silica, alumina, smectite, synthetic mica and the like can be blended. These inorganic particles are blended in the epoxy resin composition mainly for rheology control, that is, for thickening and thixotropic imparting.

  In the present invention, the cured product of the epoxy resin composition has a swelling ratio with methyl ethyl ketone of preferably 20% by mass or more, more preferably 25% by mass or more, preferably 44% by mass or less, and more preferably 38% by mass or less. . The swelling rate with the methyl ethyl ketone indicates the degree of crosslinking of the cured product of the epoxy resin composition. If the swelling ratio is less than 20% by mass, the crosslink density is too high, and the elongation of the cured product of the epoxy resin composition decreases. If it exceeds 44% by mass, the crosslink density is too small and the cured product of the epoxy resin composition Strength decreases.

  The tensile property (= maximum stress × elongation at that time / 2) of the cured product of the epoxy resin composition is preferably 100 MPa ·% or more, more preferably 150 MPa ·% or more, further preferably 200 MPa ·% or more, and 6000 MPa ·%. The following is preferable, 5500 MPa ·% or less is more preferable, and 5000 MPa ·% or less is further preferable.

  The tensile strength (maximum stress) of the cured product of the epoxy resin composition is preferably 20 MPa or more, more preferably 30 MPa or more, further preferably 50 MPa or more, preferably 500 MPa or less, more preferably 450 MPa or less, and further preferably 400 MPa or less. . Further, the elongation (breaking elongation) of the cured product of the epoxy resin composition is preferably 2% or more, more preferably 3% or more, preferably 300% or less, and more preferably 200% or less. The measuring method of tensile strength and elongation will be described later.

  The resin component of the prepreg of the present invention is preferably composed only of the epoxy resin composition, but a commercially available epoxy resin composition may be used in combination as long as the effects of the present invention are not impaired. When a commercially available epoxy resin composition is used in combination, the content of the commercially available epoxy resin composition in the resin component is preferably 95% by mass or less, more preferably 90% by mass or less, and 80% by mass. More preferably, it is as follows.

  The content of the resin component in the prepreg of the present invention is preferably 15% by mass or more, more preferably 20% by mass or more, still more preferably 25% by mass or more, and preferably 65% by mass or less, more preferably 60% by mass. Hereinafter, it is more preferably 55% by mass or less. This is because if the content of the reinforcing fiber is within the above range, a good fiber-reinforced epoxy resin molded body that can fully utilize the high strength of the resin is obtained.

  In the present invention, examples of the reinforcing fiber used for the prepreg include carbon fiber, glass fiber, aramid fiber, boron fiber, alumina fiber, and silicon carbide fiber. Also, two or more of these fibers can be mixed. Among these, it is preferable to use carbon fiber.

  Examples of the carbon fibers include acrylic, pitch, and rayon carbon fibers. Among them, acrylic carbon fibers having high tensile strength are preferable. As for the form of the carbon fiber, carbon fiber obtained by twisting and firing the precursor fiber, so-called twisted yarn, untwisted carbon fiber, so-called untwisted yarn, substantially twisted on the precursor fiber Non-twisted yarn that is heat-treated without being subjected to heat treatment can be used. Non-twisted yarn or untwisted yarn is preferable in consideration of the balance between formability and strength characteristics of the fiber-reinforced composite material, and further, non-twisted yarn is preferable from the viewpoint of handleability such as adhesion between prepreg sheets. Moreover, the carbon fiber in this invention can also contain a graphite fiber.

Tensile modulus of the reinforcing fibers is preferably at least ^{10tf / mm 2 (98GPa),} 24tf / mm 2 (235GPa) or ^more, and is preferably from ^{70tf / mm 2 (686GPa),} 50tf / mm 2 (490GPa) The following is more preferable. The tensile elastic modulus is measured in accordance with JIS R7601: 1986 “Carbon fiber test method”. When the tensile elastic modulus of the reinforcing fiber is within the above range, a tubular body having high bending strength can be obtained.

  The content of the reinforcing fiber in the prepreg of the present invention is preferably 35% by mass or more, more preferably 50% by mass or more, further preferably 65% by mass or more, particularly preferably 70% by mass or more, and 85% by mass or less. More preferably, it is 84 mass% or less, More preferably, it is 80 mass% or less, Most preferably, it is 75 mass% or less. This is because if the content of the reinforcing fibers is within the above range, a good fiber-reinforced epoxy resin material that can fully utilize the high strength of the resin is obtained.

  Examples of the form of the reinforcing fiber in the prepreg include a long fiber aligned in one direction, a bi-directional woven fabric, a multiaxial woven fabric, a non-woven fabric, a mat, a knit, and a braid. Here, the long fiber means a single fiber or a fiber bundle substantially continuous for 10 mm or more. A so-called unidirectional prepreg using long fibers aligned in one direction has a high fiber strength direction and a high strength utilization rate in the fiber direction because the fibers are less bent. In addition, when the unidirectional prepreg is formed by appropriately laminating a plurality of prepregs so that the arrangement directions of the reinforcing fibers are different, the elastic modulus and strength in each direction of the molded product can be easily designed.

  The shape of the prepreg of the present invention is preferably a sheet shape. When the prepreg is formed into a sheet, the thickness is preferably 0.01 mm or more, more preferably 0.03 mm or more, preferably 1.0 mm or less, more preferably 0.9 mm or less.

The density of the prepreg of the present invention is preferably 1.45 g / cm ³ or more, more preferably 1.47 g / cm ³ or more, still more preferably 1.48 g / cm ³ or more, and 1.75 g / cm ³ or less. Preferably, it is 1.72 g / cm ³ or less, more preferably 1.69 g / cm ³ or less. This is because, if the density is within the above range, a good fiber-reinforced epoxy resin material that can fully utilize the reinforcing effect of the carbon fiber can be obtained.

  A known method is used as a method for producing the prepreg of the present invention. For example, a prepreg can be produced by impregnating the epoxy resin composition into a reinforcing fiber such as carbon fiber. Specifically, a wet method in which the epoxy resin composition is dissolved in a solvent such as methyl ethyl ketone and methanol to lower the viscosity and impregnated into the reinforcing fiber, and a hot method in which the epoxy resin composition is reduced in viscosity by heating and impregnated into the reinforcing fiber. It can be produced by a method such as a melt method. The wet method is a method of obtaining a prepreg by evaporating a solvent while evaporating a reinforcing fiber after being immersed in a solution made of an epoxy resin composition and heating using an oven or the like. In the hot melt method, a method in which a reinforcing fiber is directly impregnated with an epoxy resin composition whose viscosity has been reduced by heating, or a film in which an epoxy resin composition is once coated on a release paper is prepared, and then a reinforcing fiber is prepared. There is a method of making a prepreg by impregnating the epoxy resin composition by overlapping and heating such a film from both sides or from one side. The hot melt method is preferable because the solvent does not substantially remain in the prepreg.

  The fiber reinforced epoxy resin molded product is obtained by curing the epoxy resin composition contained in the prepreg of the present invention. As a method for producing a tubular body made of a fiber reinforced epoxy resin material using the prepreg of the present invention, a known method is used. For example, the prepreg can be cut into the shape of each material constituting the tubular body, and after lamination, a method of applying pressure while heating the laminated body can be mentioned.

  Examples of methods for applying pressure while heating the prepreg laminate include a wrapping tape method and an internal pressure molding method. The wrapping tape method is a method of obtaining a molded body by winding a prepreg around a mandrel or the like. Specifically, a prepreg is wound around a mandrel, a wrapping tape made of a thermoplastic resin film is wound around the outside of the prepreg for fixing and applying pressure, and the resin is heated and cured in an oven, and then a cored bar. This is a method for removing the slag to obtain a tubular molded body. The surface of the tubular molded body may be cut and painted.

  In the internal pressure molding method, a prepreg is wound around an internal pressure applying body such as a tube made of a thermoplastic resin to form a preform, which is then placed in a mold, and then a high pressure gas is introduced into the internal pressure applying body to increase the pressure. It is a method of molding by heating and mold.

  The number of laminated prepregs constituting the tubular body made of a fiber reinforced epoxy resin material, the content of reinforcing fibers, the thickness of one prepreg, and the like are preferably appropriately changed according to desired characteristics. In particular, a bias prepreg in which the array of reinforcing fibers is arranged to be inclined with respect to the axis of the tubular body, a straight prepreg in which the array of reinforcing fibers is arranged in parallel to the axis of the tubular body, and a tubular body It is preferable to appropriately arrange a hoop prepreg in which an array of reinforcing fibers is arranged at right angles to the axis to give the tubular body necessary rigidity and strength. The surface of the tubular molded body may be cut and painted.

  The tubular body is preferably formed by winding and laminating a plurality of prepregs and curing the resin composition contained in these prepregs. The number of laminated prepregs constituting the tubular body is preferably 5 layers or more, more preferably 7 layers or more, still more preferably 9 layers or more, preferably 30 layers or less, more preferably 28 layers or less, still more preferably 26. Below the layer.

  When the tubular body is composed of a plurality of prepregs, it is preferable to use the prepreg of the present invention as the outermost prepreg located on the outermost side. The initial failure of the tubular body occurs from the outermost layer of the tubular body. Therefore, by using the prepreg of the present invention, which is excellent in mechanical strength, as the outermost layer, it is possible to prevent the tubular body from being initially destroyed and to further increase the strength of the tubular body. When the tubular body is composed of three or more prepregs, it is preferable to use the prepreg of the present invention for the outermost prepreg and the prepreg inscribed in the outermost prepreg. The outermost prepreg and the prepreg inscribed in the outermost prepreg may use different prepregs, but preferably use the same prepreg.

The tensile elastic modulus of the reinforcing fiber contained in the outermost prepreg and / or the prepreg inscribed in the outermost prepreg is preferably 10 tf / mm ² (98 GPa) or more, more preferably 15 tf / mm ² (147 GPa) or more, more preferably It is 20 tf / mm ² (196 GPa) or more, preferably 38 tf / mm ² (373 GPa) or less, and more preferably _30 tf / mm ² (294 GPa) or less. If the tensile elastic modulus of the reinforcing fiber contained in these prepregs is within the above range, the initial fracture of the tubular body can be further suppressed.

  Moreover, it is preferable to use at least one prepreg having a density lower than that of the outermost prepreg (hereinafter sometimes referred to as a lightweight prepreg) as the other prepreg positioned inside the outermost prepreg. By using a prepreg having a low density, the tubular body can be reduced in weight. Moreover, since a prepreg having a low density usually has a small content of reinforcing fibers, the use of such a prepreg tends to lower the mechanical strength of the tubular body. However, since the initial fracture is suppressed by using the prepreg of the present invention as the outermost prepreg, the weight can be reduced while maintaining the mechanical strength of the tubular body.

The density difference between the outermost prepreg and the light prepreg (outermost prepreg−light prepreg) is preferably 0.08 g / cm ³ or more, more preferably 0.10 g / cm ³ or more, and further preferably 0.12 g / cm ³ and preferably from 0.28 g / cm ³ or less, more preferably 0.26 g / cm ³ or less, further preferably 0.24 g / cm ³ or less. If the difference in density is within the above range, the weight can be reduced while maintaining the strength.

The lightweight prepreg is not particularly limited, and a known prepreg can be used. In addition, it is also preferable to use the prepreg of the present invention as the lightweight prepreg. The density of lightweight prepreg is preferably 1.35 g / cm ³ or more, more preferably 1.40 g / cm ³ or more, preferably 1.55 g / cm ³ or less, more preferably 1.50 g / cm ³ or less is there.

When using a lightweight prepreg, it is preferable to make the tensile elastic modulus of the reinforcing fiber contained in the lightweight prepreg larger than the tensile elastic modulus of the reinforcing fiber contained in the outermost prepreg. By setting it as such a structure, weight reduction can be achieved, maintaining the mechanical strength of a tubular body. The tensile modulus of the reinforcing fibers, wherein the weight prepreg contains ^is preferably at least 30tf / mm 2 (294GPa), more preferably 40tf ^/ mm 2 (392GPa) or more, more preferably be 46tf ^/ mm 2 (451GPa) or 70 tf / mm ² (686 GPa) or less, more preferably 60 tf / mm ² (588 GPa) or less, and still more preferably 50 tf / mm ² (490 GPa) or less. If the tensile elastic modulus of the reinforcing fiber contained in the lightweight prepreg is within the above range, the weight can be reduced while maintaining the mechanical strength of the tubular body.

  The light weight prepreg can reduce the mass of the tubular body as the number of used sheets increases. The position of the lightweight prepreg is not particularly limited, but it is preferable to dispose the lightweight prepreg as much as possible. Therefore, it is preferable that the innermost prepreg located on the innermost side is a lightweight prepreg. Two or more lightweight prepregs may be used. In this case, the order of the prepregs is preferably arranged so that the lightweight prepregs are continuous. That is, it is more preferable that the lightweight prepreg is continuously arranged from the innermost prepreg to a desired number.

  As the tubular body, a plurality of prepregs are wound and laminated, the prepreg of the present invention is used for the outermost prepreg located on the outermost side, and at least one prepreg located on the inner side of the outermost prepreg The aspect which is a lightweight prepreg whose density is smaller than the said outermost prepreg is preferable. Specifically, n prepregs are wound and laminated, the prepreg of the present invention is used as the outermost prepreg and the prepreg inscribed in the outermost prepreg, and from the innermost prepreg to the n-3rd sheet A mode in which a light-weight prepreg is used as the prepreg is preferable (where n is 5 or more). For example, when the tubular body is composed of eight prepregs, the prepreg of the present invention is used for the outermost prepreg (eighth sheet) and the prepreg inscribed in the outermost prepreg (seventh sheet), and the innermost prepreg ( A mode in which a lightweight prepreg is used as the first to fifth prepregs is preferred. The outermost prepreg, the prepreg inscribed in the outermost prepreg, and the lightweight prepreg are preferably prepregs of the present invention having different densities.

  The length of the tubular body is preferably 40 inches (101.6 cm) or more, more preferably 41 inches (104.1 cm) or more, preferably 49 inches (124.5 cm) or less, more preferably 48 inches ( 121.9 cm) or less. If the length of the tubular body is within the above range, the operability of the golf club using the golf club shaft made of this tubular body will be good. Further, the mass of the tubular body is preferably 30 g or more, more preferably 35 g or more, preferably 80 g or less, more preferably 75 g or less. If the mass is 30 g or more, the shaft is sufficiently thick and the mechanical strength is further improved, and if it is 80 g or less, the shaft is not too heavy and the operability is improved.

  The wall thickness of the tubular body is preferably 0.5 mm or more, more preferably 0.6 mm or more, preferably 4 mm or less, more preferably 3.5 mm or less. If the thickness of the tubular body is within the above range, good or bad is obtained. The wall thickness of the tubular body can be controlled by adjusting the position of the thin-walled portion, thereby controlling the center of gravity of the tubular body and the bending position.

  A tubular body made of a fiber reinforced epoxy resin material formed using the prepreg can be suitably used for, for example, a golf club shaft, a fishing rod, a tennis racket, a badminton racket, and the like.

  Hereinafter, the present invention will be described in detail by way of examples. However, the present invention is not limited to the following examples, and all modifications and embodiments without departing from the gist of the present invention are not limited thereto. Included in range.

[Evaluation method]
(1) Preparation of test piece [Preparation of resin tensile test piece and test piece for methyl ethyl ketone swelling test]
An epoxy resin component was dissolved in methyl ethyl ketone (MEK) to prepare an MEK solution of an epoxy resin (MEK content 30%) so as to be the same as the composition of the epoxy resin composition shown in Tables 1 to 4. The obtained MEK solution of epoxy resin was dried, heated and melted, added with a curing agent and a curing aid, and stirred. The obtained epoxy resin composition was poured into a casting mold having a thickness of 2 mm, and cured at 130 ° C. for 2 hours. A tensile test specimen was molded from the cured resin plate according to JIS-K7162 (1994) test specimen 1BA. In addition, a 2 cm × 2 cm square test piece was cut out and used as a test piece for methyl ethyl ketone swelling test.

[Test specimen for tensile test of fiber reinforced epoxy resin molding]
Ten prepregs were cut and laminated so that the fiber direction was constant. It is sandwiched between 0.1 mm release sheets and pressed using a 1 mm spacer under conditions of 80 ° C. × 30 minutes + 130 ° C. × 2 hours to cure the epoxy resin to obtain a fiber reinforced epoxy resin molded body sheet. It was. The obtained fiber-reinforced epoxy resin molded body sheet was cut so that the length: 100 mm in the fiber vertical direction and the width: 10 mm in the fiber direction to prepare a test piece for a tensile test.

(2) Methyl ethyl ketone swelling test The test piece (2 cm square, thickness 2 mm) for methyl ethyl ketone swelling test obtained above was immersed in 100 mL of methyl ethyl ketone and held at 40 ° C for 48 hours. The mass of the test piece before and after immersion was measured, and the methyl ethyl ketone swelling ratio was calculated as follows.
Swelling ratio = 100 × [mass of test piece after swelling test−mass of test piece before swelling test] / mass of test piece before swelling test

(3) Tensile test (maximum stress)
As shown in FIG. 1, the tensile test was performed at a tensile speed of 1 mm / min using a Shimadzu autograph (manufactured by Shimadzu Corporation). Fig.1 (a) is explanatory drawing which illustrates typically the tension test method about the test piece 12 which consists of hardened | cured material of an epoxy resin composition. FIG.1 (b) is the side view which looked at the chuck | zipper 10 which grasps the test piece 12 of Fig.1 (a) from the side surface. In FIG. 1B, unevenness for preventing slipping is provided on the inner side of the chuck 10, but it is not shown. FIG.1 (c) is explanatory drawing which illustrates typically the tension test method about a fiber reinforced epoxy resin molded object. 1A and 1C, the arrow direction is the direction of the tensile test. As shown in FIG. 1 (c), an aluminum tag 14 having a length of 4 mm, a width of 1.5 mm and a thickness of 0.5 mm is attached to a test piece 15 made of a fiber-reinforced epoxy resin molded body with a cyanoacrylate adhesive. A tensile test was performed in a direction perpendicular (90 degrees) to the direction of the reinforcing fibers 16. Moreover, about the hardened | cured material of the epoxy resin composition, the tensile characteristic was shown by the maximum stress x the elongation at that time / 2 (MPa *%).

(4) Three-point bending test As shown in FIG. 2, the tubular body 18 is supported at two points from below so that the distance between the fulcrums 20 and 20 is 300 mm. A load F (peak value) when the tubular body was broken was measured by applying a load F from above. The midpoint 22 where the load F is applied to the tubular body 18 is located at the center of the tubular body. The measurement was performed under the following conditions.
Test apparatus: Shimadzu autograph load speed: 20 mm / min

(5) Prepreg tack test The prepreg tack was measured using an adhesive tester for rubber / adhesive bodies (PICMA tack tester P-2, manufactured by Toyo Seiki Co., Ltd.). The measurement conditions were descending speed: 1000 mm / second, pressure bonding time: 0 second, peeling speed: 1000 mm / second (adhesion time 1 second).

(6) Drapability test The drapeability of the prepreg was evaluated by the ease of winding at the time of producing the tubular body. Those with good workability were marked with “◯”, and those with poor workability were marked with “x”.

[Preparation of prepreg]
The epoxy resin was dissolved in methyl ethyl ketone so as to have the composition shown in Tables 1 to 4 to prepare a MEK solution of the epoxy resin (MEK content: 30% by mass). A curing agent and a curing aid were added to the MEK solution of the obtained epoxy resin and stirred to prepare an epoxy resin composition solution. The epoxy resin composition solution was applied to release paper and dried at 80 ° C. to 90 ° C. for 3 minutes to prepare an epoxy resin composition sheet. An epoxy resin composition sheet obtained on a carbon fiber sheet having a fiber basis weight of 100 g / m ² was impregnated by a hot melt method to prepare a prepreg having a carbon fiber content of 70% by mass.

  The evaluation results for the epoxy resin composition and the prepreg are shown in Tables 1 to 4.

The raw materials used in Tables 1 to 4 are as follows.
Bisphenol A type epoxy resin (epoxy equivalent: 190 g / eq): manufactured by Mitsubishi Chemical Corporation, jER828EL (liquid at normal temperature, viscosity (25 ° C.): 120 to 150 P)
Bisphenol A type epoxy resin (epoxy equivalent: 1975 g / eq): manufactured by Mitsubishi Chemical Corporation, jER1007 (solid at normal temperature)
Bisphenol F type epoxy resin (epoxy equivalent: 165 g / eq): manufactured by Mitsubishi Chemical Corporation, jER806 (liquid at normal temperature, viscosity (25 ° C.): 15-25P)
Bisphenol F type epoxy resin (epoxy equivalent: 1070 g / eq): manufactured by Mitsubishi Chemical Corporation, jER4005P (solid at normal temperature)
Phenol novolac type epoxy resin (epoxy equivalent: 180 g / eq): manufactured by Mitsubishi Chemical Corporation, jER154 (number of epoxy groups per molecule: 3 or more)
Polyvinyl formal: made by JNC, Vinylec (registered trademark) E
Dicyandiamide: manufactured by Mitsubishi Chemical Corporation, DICY7
Urea derivative: DCMU-99 (3- (3,4-dichlorophenyl) -1,1-dimethylurea) manufactured by Hodogaya Chemical Co., Ltd.
T700SC: carbon fiber manufactured by Toray Industries, Inc., trading card T700SC (tensile modulus 24 tf / mm ² (235 GPa))
T800SC: carbon fiber manufactured by Toray Industries Inc., Trading Card (registered trademark) T800SC (tensile elastic modulus 30 tf / mm ² (294 GPa))
M40JB: carbon fiber manufactured by Toray Industries, Inc., trading card M40JB (tensile elastic modulus 40 tf / mm ² (392 GPa))
M50JB: carbon fiber manufactured by Toray Industries, Inc., trading card M50JB (tensile elastic modulus 50 tf / mm ² (490 GPa))
XN-15: Carbon fiber made from Japanese graphite fiber, GRANOC XN-15 (tensile elastic modulus 15 tf / mm ² (147 GPa))
YSH-60A: Carbon fiber made of Japanese graphite fiber, GRANOC YSH-60A (tensile elastic modulus 63 tf / mm ² (618 GPa))
YS-80A: Carbon fiber made from Japanese graphite fiber, GRANOC YS-80A (tensile elastic modulus 80 tf / mm ² (785 GPa))

  From Tables 1 to 4, an epoxy resin composition containing a predetermined amount of a novolac type epoxy resin, a bisphenol A type epoxy resin, and a bisphenol F type epoxy resin, and a cured product having a methyl ethyl ketone swelling ratio of 20% by mass to 44% by mass Prepreg No. using the product. PP1, PP2, PP5 to PP7, and PP9 to PP12 have good tack and drape properties. Moreover, it turns out that the fiber reinforced epoxy resin material which consists of these prepregs has high tensile strength.

  Prepreg No. PP3 and PP4 are inferior in drape because the epoxy equivalent of the entire epoxy resin component is too high. Prepreg No. PP8 has an excessively high methyl ethyl ketone swelling ratio of 45.6% by mass, so that the tensile strength of the fiber-reinforced epoxy resin material is inferior. Prepreg No. Since PP13 and PP14 have a methyl ethyl ketone swelling ratio as low as 19.6 mass% and 13.2 mass%, they are inferior in drapability. Prepreg No. PP15 did not contain a bisphenol F-type epoxy resin, and the methyl ethyl ketone swelling ratio was too low at 13.1% by mass, so a test piece for a tensile test could not be prepared.

[Production of tubular body made of fiber reinforced epoxy resin material]
A tubular body made of a fiber reinforced epoxy resin material was produced by a sheet winding method. That is, as shown in FIG. 3, the prepregs 1 to 8 were wound around a mandrel in order. The prepreg 1 constitutes the innermost layer, and the prepreg 8 constitutes the outermost layer. The prepregs 1, 4, 5, 7, and 8 are straight prepregs in which the reinforcing fibers are arranged in parallel to the axis of the tubular body. The prepregs 2 and 3 are bias prepregs in which the arrangement direction of the reinforcing fibers is inclined with respect to the axis of the tubular body. The prepreg 6 is a hoop prepreg in which the reinforcing fibers are arranged in a direction perpendicular to the axis of the tubular body. As shown in FIG. 4, the prepreg 2 and the prepreg 3, and the prepreg 5 and the prepreg 6 were bonded together so that the inclination directions of the reinforcing fibers intersected. As prepregs 1 to 8, those shown in Tables 5 to 10 were used. A tape was wound around the outer peripheral surface of the obtained wound body and heated to perform a curing reaction. The winding conditions and curing conditions are shown below. 3 and 4, the dimensions are displayed in mm.

Winding conditions:
Rolling speed: 34Hz
Tape: PT-30H manufactured by Shin-Etsu Chemical Co., Ltd., tension 6000 ± 100 gf
Pitch: 2.0mm
Spindle speed: 1870-1890Hz
Curing conditions:
(1) Temperature rise from room temperature to 80 ° C in 30 minutes (2) Hold at 80 ° C ± 5 ° C for 30 minutes ± 5 minutes (3) Temperature rise from 80 ° C to 130 ° C in 30 minutes (4) 130 ° C ± 5 ° C Hold for 120 minutes ± 5 minutes.

P-805S-3: Toray prepreg P805S-3 (carbon fiber: M30S (tensile elastic modulus 30 tf / mm ² (294 GPa)), resin content: 40% by mass, density 1.47 g / cm ³ ), manufactured by Toray Industries, Inc.

  As shown in Table 5, an epoxy resin composition containing a predetermined amount of novolac type epoxy resin, bisphenol A type epoxy resin, and bisphenol F type epoxy resin, and having a cured product with a methyl ethyl ketone swelling ratio of 20% by mass to 44% by mass The tubular body No. 1, 2, 5-7, 9-12 have high three-point bending strength.

  The tubular body made of the fiber reinforced epoxy resin material produced using the prepreg of the present invention can be suitably used for, for example, a golf club shaft, a fishing rod, a tennis racket, a badminton racket and the like.

1-8: Prepreg, 10: Chuck, 12: Test piece made of cured epoxy resin composition, 14: Aluminum tag, 16: Reinforced fiber, 18: Tubular body, 20: Support point, 22: Midpoint between the support points

Claims (17)

A prepreg containing an epoxy resin composition and reinforcing fibers,
The epoxy resin composition contains, as an epoxy resin component, a novolac type epoxy resin, a bisphenol A type epoxy resin and a bisphenol F type epoxy resin,
The bisphenol A type epoxy resin contains a solid bisphenol A type epoxy resin at 25 ° C.,
The bisphenol F-type epoxy resin contains a liquid bisphenol F-type epoxy resin at 25 ° C.,
The content of the novolac type epoxy resin in the entire epoxy resin component is 2% by mass to 19% by mass, and the mass ratio of bisphenol A type epoxy resin to bisphenol F type epoxy resin in the epoxy resin component (bisphenol A type epoxy resin) / Bisphenol F-type epoxy resin) is 0.3 to 2.5 , and the epoxy equivalent (g / eq) of the entire epoxy resin component is 200 to 400,
The cured product of the epoxy resin composition has a swelling ratio with methyl ethyl ketone of 20% by mass to 44% by mass. 2. The prepreg according to claim 1, wherein the bisphenol F-type epoxy resin consists only of a liquid bisphenol F-type epoxy resin at 25 ° C. 3. The prepreg according to claim 1 or 2, wherein the bisphenol A type epoxy resin contains a bisphenol A type epoxy resin that is solid at 25 ° C and a bisphenol A type epoxy resin that is liquid at 25 ° C. The prepreg according to any one of claims 1 to 3, wherein an epoxy equivalent of the bisphenol A type epoxy resin that is solid at 25 ° C is 300 g / eq to 20000 g / eq. The prepreg as described in any one of Claims 1-4 in which the said epoxy resin composition contains 2-12 mass parts of thermoplastic resins further with respect to 100 mass parts of epoxy resin components. The prepreg according to any one of claims 1 to 5, wherein the epoxy resin composition contains dicyandiamide as a curing agent and a urea derivative as a curing accelerator. The prepreg as described in any one of Claims 1-6 in which the said epoxy resin composition contains 13-40 g of dicyandiamide with respect to 1 mol of epoxy groups of an epoxy resin component as a hardening | curing agent. The prepreg according to any one of claims 5 to 7 , comprising polyvinyl formal as the thermoplastic resin. The prepreg according to any one of claims 1 to 8 , wherein a content of the reinforcing fiber is 65% by mass to 85% by mass. The prepreg according to any one of claims 1 to 9 , wherein the reinforcing fiber is a carbon fiber. The tensile modulus of the reinforcing ^{fibers, 10tf / mm 2 ~70tf / mm} 2 a prepreg according to any one of claims 1 to 10 is. The fiber reinforced epoxy resin molding which hardens the epoxy resin composition which the prepreg as described in any one of Claims 1-11 contains. The tubular body made from the fiber reinforced epoxy resin material formed using the prepreg as described in any one of Claims 1-11 . Laminating a plurality of prepregs, curing the resin composition contained in the prepregs,
The outermost prepreg located on the outermost side is the prepreg according to any one of claims 1 to 11 ,
The prepreg located inside the outermost prepreg is a tubular body made of a fiber reinforced epoxy resin material, at least one of which is a prepreg having a density lower than that of the outermost prepreg. The fiber reinforced epoxy according to claim 14 , wherein the tensile elastic modulus of the reinforcing fiber contained in the prepreg having a density lower than that of the outermost prepreg is larger than the tensile elastic modulus of the reinforcing fiber contained in the outermost prepreg. Tubular body made of resin material. The tensile modulus of the reinforcing fibers contained in the outermost prepreg is at 10tf / mm ² or more 38tf / mm ² or less, the tensile modulus of the reinforcing fiber density than the outermost prepreg is contained in a small prepreg 30tf / mm ² or more 70Tf / mm ² or less is claim 14 or fiber-reinforced epoxy resin material made of a tubular body according to 15. A golf club shaft comprising a tubular body made of the fiber-reinforced epoxy resin material according to any one of claims 13 to 16 .

Images