JPH09194611A - Preimpregnated material and its composite - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a preimpregnated material (prepreg) having excellent tackiness and draping property even if a high elastic modulus carbon fiber is used or a reinforced fiber is highly contained. SOLUTION: This prepreg comprises a reinforced fiber and a matrix resin being a thermosetting resin, and has a complex viscosity η* of the matrix resin in the range of 200-2,000Pa.s when dynamic viscoelasticity is measured at 50 deg.C and at measured frequency of 0.5Hz and an energy loss, tanδ, in the range of 0.3-5, and a composite molded therefrom is also provided.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a prepreg and a composite (fiber reinforced composite material), and more particularly to a composite suitable for use in sports equipment and aerospace parts and a prepreg used for molding the composite.

[0002]

2. Description of the Related Art Composites (fiber reinforced composite materials) having a prepreg consisting of reinforcing fibers and a matrix resin as an intermediate base material are particularly excellent in mechanical properties, so that they are used in sports such as golf clubs, tennis rackets, and fishing rods. It is widely used for aerospace applications and general industrial applications, including product applications.

Various methods are used for manufacturing composites, but a method using a prepreg which is a sheet-shaped intermediate base material in which reinforcing fibers are impregnated with a matrix resin is widely used. In this method, a molded product is usually obtained by heating a plurality of prepregs after laminating them.

As the matrix resin used in the prepreg, both thermosetting resins and thermoplastic resins are used, but in most cases thermosetting resins are used, and of these epoxy resins are mainly used.

When handling a prepreg using an epoxy resin, it is often the problem of tackiness (adhesion) between the prepregs and drapability (suppleness) of the prepreg. These properties greatly affect the workability when handling the prepreg.

That is, if the tackiness of the prepreg is too small, the prepreg that has been pressed against the prepreg immediately peels off in the prepreg laminating step, which hinders the laminating operation. In such a case, it becomes necessary to raise the working environment temperature until a suitable tackiness is obtained. On the other hand, if the tackiness of the prepreg is too great, the prepreg will be stuck due to its own weight, for example, if it is accidentally overlaid, and it will be difficult to peel it off and correct it.

If the drape property of the prepreg is poor, the prepreg is stiff, so that the laminating workability is significantly reduced, and the laminated prepreg does not exactly follow the curved surface of the mold or the shape of the mandrel, and becomes wrinkled. The reinforcing fibers are broken, resulting in defects in the molded product. Even in such a case, it is necessary to raise the working environment temperature, but it is difficult to balance with the tackiness, and these are very serious problems in the molding work.

These problems are particularly likely to occur when molding a golf shaft, a fishing rod or the like by winding a prepreg around a mandrel. If the balance between tackiness and drapeability is improper, the wound prepreg may peel off and molding may not be possible.

In recent years, in particular, the weight reduction has been promoted for use in sports equipment such as golf shafts and fishing rods, and there is a demand for a prepreg suitable for a lightweight design. As a reinforcing fiber, a prepreg using a high elastic modulus fiber, particularly a high elastic modulus carbon fiber has recently been demanded particularly in such a market because it facilitates a lightweight design. Moreover, the demand for prepregs having a high content of reinforcing fibers is also increasing.

However, when a high elastic modulus carbon fiber is used as the reinforcing fiber, the drape property tends to be low.
Also, when using a prepreg with a high reinforcing fiber content,
Since the amount of resin distributed on the surface of the prepreg is small, it tends to exhibit the property of low tackiness. In particular, a prepreg using a high elastic modulus carbon fiber and having a high reinforcing fiber content tends to have low tackiness and drapability. Therefore, when the conventional resin is used, there is a problem that either tackiness, drapeability, or both of them are insufficient.

An epoxy resin composition containing a high-molecular-weight epoxy resin for the purpose of optimizing tackiness and drapeability of a prepreg and improving molding workability is disclosed in JP-A-62-127317 and JP-A-62-127317. 63-30802
No. 6 discloses this. In addition, JP-A-2-2054
Japanese Patent Publication No. 6 discloses an epoxy resin composition containing a nitrile rubber-modified epoxy resin for the purpose of optimizing drapeability and resin flow.

However, these methods give satisfactory results when it is difficult to achieve both tackiness and drapeability, such as prepregs having a high content of reinforcing fibers, which use carbon fibers of high elastic modulus as reinforcing fibers. Can't get

As a method for improving the tackiness of the prepreg, it is known to blend an epoxy resin with an organic polymer compound such as a thermoplastic resin or an elastomer. For example, JP-A-58-8724 and JP-A-SHO-6
No. 2-169829, a method of blending a polyvinyl formal resin, JP-A-55-27342, JP-A-55-108443, and JP-A-56-2.
119, a method for adding a polyvinyl acetal resin, JP-A-52-30187, a method for adding a polyvinyl butyral resin, JP
A method of blending the polyester polyurethane disclosed in JP-A-117423 and a method of blending polyvinyl ether disclosed in JP-A-4-130156 are known.

However, in general, in the method of adding an organic polymer compound to an epoxy resin, there is a restriction that the resin viscosity increases with the addition and the drape property deteriorates. With the prepreg,
It is difficult to find a resin that has both satisfactory tackiness and drapeability. These publications do not disclose any guidelines for achieving both tackiness and drapeability.

Further, JP-A-2-92920 and JP-A-4-46923 disclose compositions comprising an epoxy resin, a polyester thermoplastic elastomer and a curing agent. However, in each of these publications, the purpose is to improve the tensile strength and impact resistance of the composite material, and no consideration has been given to the problem of improving tackiness without sacrificing drapeability and impregnation. And does not suggest a solution.

Further, European Patent No. 381625 (corresponding to JP-A-2-233754) comprises a liquid copolymer based on epoxy resin, butadiene and acrylonitrile and a segmented copolymer comprising copolyester, copolyamide and the like. , An epoxy resin composition used for a structural hot-melt adhesive or a matrix resin or a surface coating is disclosed, but similar to the above, regarding the problem of improving tackiness without sacrificing drapeability and impregnation Has not been examined, nor does it suggest a solution.

On the other hand, many attempts have been made to improve the interlaminar toughness in order to improve the impact resistance, particularly the compressive strength after impact, of the fiber-reinforced composite material obtained by laminating and curing prepregs. For example, US Pat. No. 3,472,730
U.S. Pat. No. 4,539,253 (corresponding JP-A-60-231738), U.S. Pat. No. 4,60.
4,319, JP-A-51-58484 (JP-B-58-31296), JP-A-54-3879, JP-A-56-115216, and JP-A-60-4.
No. 4334, No. 60-63229, No. 63-162732, No. 58-20575.
Japanese Patent Publication No. 8 and Japanese Patent Publication No. 61-29265 disclose a technique of disposing a film or fine particles of a thermosetting resin or a thermoplastic resin between layers to improve the interlayer strength.

However, unlike the case where the composition obtained by dissolving a thermoplastic resin in an epoxy resin is used as a matrix resin, such a technique exists as a completely different phase between the thermoplastic resin and the epoxy resin composition. Therefore, when the thermoplastic resin takes the form of a film and covers the entire surface, the surface loses tackiness. Further, when the particles of the thermoplastic resin are used, the epoxy resin composition does not lose its tackiness because it is sufficiently exposed on the surface, but the tackiness when the particles are not used can be almost maintained. ,
No further improvement in tackiness can be expected.

[0019]

SUMMARY OF THE INVENTION An object of the present invention is to provide a prepreg which is excellent in tackiness and drapability, even if a high elastic modulus carbon fiber is used or a high reinforcing fiber content is used. Especially.

[0020]

The present inventors have found that a prepreg using a matrix resin having a specific viscoelasticity is excellent in both tackiness and drapeability, and arrived at the present invention. That is, the prepreg of the present invention comprises a reinforcing fiber and a matrix resin, the matrix resin is a thermosetting resin, and the complex viscosity of the matrix resin in dynamic viscoelasticity measurement at a measurement frequency of 0.5 Hz and 50 ° C. η ^* is in the range of 200 to 2,000 Pa · s, and energy loss tan δ is in the range of 0.3 to 5, which is a prepreg.

Further, the composite according to the present invention is a composite obtained by curing the above prepreg.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION

(Explanation of Matrix Resin) The prepreg of the present invention comprises a reinforcing fiber and a matrix resin, and a thermosetting resin is used as the matrix resin. As the matrix resin, a composition made of an epoxy resin, a phenol resin, a vinyl ester resin, an unsaturated polyester resin, a bismaleimide resin, a cyanate resin, a urethane resin or the like is used, and an epoxy resin composition is particularly preferably used.

The epoxy resin composition used in the prepreg of the present invention is preferably an epoxy resin composition comprising at least (1) epoxy resin (2) curing agent (3) organic polymer compound.

As the epoxy resin, a compound having a plurality of epoxy groups in the molecule is used. In particular, an epoxy resin having an amine, a phenol, or a compound having a carbon-carbon double bond as a precursor is preferable. For example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin or other bisphenol type epoxy resin, naphthalene type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin or other novolac type epoxy resin, tetra Glycidylamine-type epoxy resins such as glycidyldiaminodiphenylmethane, triglycidylaminophenol, and tetraglycidylxylenediamine, glycidylether-type epoxy resins such as tetrakis (glycidyloxyphenyl) ethane and tris (glycidyloxy) methane, and combinations thereof. Is preferably used.

Examples of such bisphenol type epoxy resin include bisphenol A type "Epicoat" 828, "Epicoat" 1001, "Epicoat" 1004 (produced by Yuka Shell Epoxy Co., Ltd.) and YD1.
28 (manufactured by Tohto Kasei Co., Ltd.), "Epiclon" 840,
"Epiclone" 850, "Epiclone" 855, "Epiclone" 860, "Epiclone" 1050 (manufactured by Dainippon Ink and Chemicals, Inc.), ELA128 (Sumitomo Chemical Co., Ltd.)
Commercially available products such as PRODUCT PRODUCTS, DER331 and DER331 (made by Dow Chemical Co.) can be used.

As the bisphenol F type, "Epiclone" 830 (manufactured by Dainippon Ink and Chemicals, Inc.),
"Epicoat" 807 (made by Yuka Shell Epoxy Co., Ltd.)
Etc. can be used.

Examples of the phenol novolac type epoxy resin include "Epicoat" 152 and "Epicoat" 154.
Commercially available products such as (Yukaka Shell Epoxy Co., Ltd.), DER485 (manufactured by Dow Chemical Co., Ltd.), and EPN1138, 1139 (manufactured by Ciba-Geigy Co.) can be used.

As the curing agent, a compound having an active group capable of reacting with an epoxy group or a compound serving as a polymerization catalyst can be used. Such curing agents include aromatic amines such as diaminodiphenylmethane, diaminodiphenylsulfone, aliphatic amines, imidazole derivatives, dicyandiamide, tetramethylguanidine, thiourea-added amines, and carboxylic acids such as methylhexahydrophthalic anhydride. Examples thereof include acid anhydrides, carboxylic acid hydrazides, carboxylic acid amides, polyphenol compounds, novolac resins, polymercaptans, and Lewis acid complexes such as boron trifluoride ethylamine complex. Also, microcapsules of these curing agents can be preferably used in order to enhance the storage stability of the prepreg.

These hardening agents may be combined with a suitable hardening aid to enhance the hardening activity. As a preferred example, 3- (3,4-dichlorophenyl) -1,1-dimethylurea (DCMU) is added to dicyandiamide.
And the like, and examples of combining a carboxylic acid anhydride or a novolac resin with a tertiary amine as a curing aid. Further, the epoxy resin and the curing agent, or a product obtained by pre-reacting a part of them may be blended in the composition.

Further, an organic polymer compound such as a thermoplastic resin or an elastomer is blended for controlling viscoelasticity. As a preferable example of the thermoplastic resin, as a polyvinyl acetal resin, a compatibility with an epoxy resin, a reason that it does not adversely affect the physical properties of the composite,
"Denka Butyral" and "Denka Formal" (manufactured by Denki Kagaku Kogyo Co., Ltd.), "Vinilec" (Chisso Co., Ltd.)
), As a phenoxy resin, "UCAR" PKHP
(Manufactured by Union Carbide), "Macromelt" (manufactured by Henkel Hakusui Co., Ltd.) as a polyamide resin, "Amilan" CM4000 (manufactured by Toray Co., Ltd.), "Ultem" (manufactured by General Electric Co.) as a polyimide,
“Matrimid” 5218 (manufactured by Ciba), “Victrex” as polysulfone (Mitsui Toatsu Chemicals, Inc.)
Manufactured by Union Carbide).

As the polyvinyl acetal resin, one having polyvinyl formal having a vinyl formal portion of 60% by weight or more is preferable because it is excellent in mechanical properties.

Of these thermoplastic resins, those having a flexural modulus of 10 MPa or more at room temperature, specifically 25 ° C., are preferable because it is difficult to reduce the modulus of elasticity of the cured product of the epoxy resin composition. .

It is preferable that these thermoplastic resins are thermodynamically soluble in the epoxy resin at least in a high temperature state during addition and mixing. Further, even if it is soluble, if the solubility is remarkably low, a sufficient effect of enhancing the physical properties of the composite cannot be obtained. Therefore, it is preferable that the solubility is not less than a certain level.

It is preferable that the elastomer is also thermodynamically soluble in the epoxy resin at least in a high temperature state during addition and mixing. Examples of such an elastomer include a copolymer containing at least butadiene and acrylonitrile, and a polyester or polyamide thermoplastic elastomer.

The polyester-based or polyamide-based thermoplastic elastomer is a block copolymer composed of a hard segment component and a soft segment component, and has a structure in which the hard segment component is a polyester unit or a polyamide unit and has a temperature of room temperature or lower. It is a polymer having a glass transition temperature and a melting point above room temperature.

The following are possible examples of the structural unit of the hard segment component. A plurality of these structures may be contained in the same polymer. It is also possible to have either or both of a polyester unit and a polyamide unit as a hard segment component. Since the melting point of the polyester or polyamide thermoplastic elastomer affects the heat resistance of the epoxy resin composition after curing, it is preferably 100 ° C. or higher, and more preferably 140 ° C. or higher. As the soft segment component, a structural unit containing an aliphatic polyether or an aliphatic polyester is suitable.

In addition to these, it is possible to include other copolymerization components and structures. As such other copolymerization component, for example, a compound containing a phenolic hydroxyl group,
Specific examples include bisphenol A and hydroxybenzoic acid, and examples of other structures include a copolymer block having a carbonic acid ester bond, a urethane bond, or the like.

The thermoplastic elastomer is synthesized by a known method. A typical example is Japanese Patent Publication No. Sho 48-411.
5, Japanese Patent Publication No. 48-4116, Japanese Patent Laid-Open No. 47-
25295, JP-A-48-29896, JP-A-48-19696, and JP-A-48-29896.
JP, JP-A-50-159586, JP, JP-A-51
-111894, JP-A-51-127198, JP-A-51-144490, and JP-A-52-456.
93, JP-A-55-147546, JP-A-55-133424, and JP-A-3-47835.

Also, many commercially available products can be used. As a commercially available polyester-based thermoplastic elastomer, Toray
DuPont's "Hytrel", Toyobo Co., Ltd.'s "Perprene", Akzo's "ARNITEL", General Electric's "LOMOND" can be mentioned. As the polyamide thermoplastic elastomer,
Examples thereof include "VESTAMID" manufactured by Huls, "PEBAX" manufactured by ATOCHEM, "Grelax A" manufactured by EMS, and "NOVAMID" manufactured by Mitsubishi Chemical Corporation.

The above organic polymer compounds can be used as a mixture of plural kinds. The preferred blending amount of the organic polymer compound is 1 to 20 parts by weight with respect to 100 parts by weight of the epoxy resin.

Further, additives such as a reactive diluent, an antioxidant and organic or inorganic particles may be included depending on the purpose.

As the reactive diluent, a monofunctional epoxy compound is preferably used. Specifically, butyl glycidyl ether, 2-ethylhexyl glycidyl ether, phenyl glycidyl ether, cresyl glycidyl ether, p-sec-butyl glycidyl ether, p-ter
Examples thereof include t-butyl glycidyl ether.

Examples of the antioxidant include phenol antioxidants such as 2,6-di-tert-butyl-p-cresol (BHT), butylated hydroxyanisole and tocophenol, and dilauryl 3,3'-thiodipropio. A sulfur-based antioxidant such as nate and distearyl 3,3′-thiodipropionate is preferably used.

As the organic particles, fine particles made of thermoplastic resin, thermosetting resin, elastomer or the like can be used. As the thermoplastic resin, particles made of polyamide resin, as the thermosetting resin, particles made of a cured product such as epoxy resin and phenol resin, as the elastomer, crosslinked rubber particles, elastomer such as butyl acrylate copolymer. Core-shell type rubber particles coated with a non-elastomeric polymer such as polymethyl acrylate can be used. These organic particles are blended mainly for improving the toughness.

As the inorganic particles, silica, alumina, smectite, synthetic mica, metal, carbon black and the like can be used. These inorganic particles are blended for the purpose of coloring, imparting thixotropy, improving elastic modulus, improving abrasion resistance, imparting conductivity, and the like.

The tackiness and drapability of the prepreg correlates with the viscoelasticity of the matrix resin. A dynamic viscoelasticity measuring method using a parallel plate is usually used for measuring the viscoelasticity of the resin. The dynamic viscoelasticity changes depending on the measurement temperature and the measurement frequency, but as a value representative of the viscoelastic behavior near room temperature, the measurement temperature is 50 ° C. and the measurement frequency is 0.5 Hz.
Complex viscosity η ^* and energy loss ta under
When nδ is in a specific range, particularly excellent prepreg characteristics are obtained, which is preferable.

The complex viscosity η ^* is particularly correlated with the drapability, and the complex viscosity η ^* is required to be 200 to 2,000 Pa · s in order to exhibit an appropriate drapability. In the case of a high-viscosity resin having a complex viscosity η ^* exceeding such a range, the drape property of the prepreg may be insufficient, or impregnation into the reinforcing fiber may be difficult. In addition, if the complex viscosity η ^* is less than the above range, the shape retention when used in a unidirectional prepreg may deteriorate.

On the other hand, the energy loss tan δ particularly correlates with the tack property, and the prepreg using the matrix resin having the smaller energy loss tan δ tends to have the better tack property.

It is necessary that the complex viscosity η ^* is in the above range and the energy loss tan δ is 0.3 to 5 in order to achieve both the drape property and the tack property. If the energy loss tan δ exceeds the range, the tackiness of the prepreg may be insufficient, and if it is less than the range, the impregnation property becomes extremely poor.

Complex viscosity η ^* and energy loss ta
In order to optimize nδ within the above range, for example, the following method can be used.

The energy loss tan δ can be controlled by appropriately selecting the type and amount of the organic polymer compound used. If the amount of addition is increased, the energy loss tan δ tends to decrease.

The complex viscosity η ^* can be controlled by appropriately selecting the type of epoxy resin used, the compounding ratio, the type and molecular weight of the organic polymer compound used, the amount added, and the like. In the case of epoxy resin or organic polymer compound consisting of the same repeating unit, the one with the larger molecular weight is
Greatly increases the complex viscosity η ^* .

In particular, a polyester-based or polyamide-based thermoplastic elastomer is preferable because it has a larger effect of lowering the energy loss tan δ with respect to the addition amount than usual thermoplastic resins and the viscoelasticity is easily adjusted.

Since the epoxy resin composition according to the present invention needs to have the energy loss tan δ within a relatively small specific range, the addition amount of the organic polymer compound is determined depending on the kind of the organic polymer compound used. Almost limited to a specific range. The complex viscosity η ^* is controlled exclusively by controlling the epoxy resin composition. Specifically, a method of blending at least two kinds of epoxy resins having a large difference in complex viscosity η ^* and adjusting the composition ratio of these is used.

As a specific example, the case of an epoxy resin composition mainly containing a general bisphenol A type epoxy resin or a bisphenol F type epoxy resin is shown. A low molecular weight liquid bisphenol A type epoxy resin or bisphenol F type epoxy resin is shown. It is possible to control the viscosity of an epoxy resin composition used by mixing a bifunctional epoxy resin such as an epoxy resin and a high molecular weight solid bisphenol A type epoxy resin or bisphenol F type epoxy resin. The liquid bisphenol A type epoxy resin or bisphenol F type epoxy resin preferably has an average molecular weight in the range of 200 to 600, more preferably 300 to 400. The solid bisphenol A type epoxy resin or bisphenol F type epoxy resin has an average molecular weight of 800 to 10,000.
Is preferable, and more preferably 850 to 4,000.
Are preferred.

Liquid bisphenol A type epoxy resin,
Commercially available bisphenol F type epoxy resins include "Epicote" 828, "Epicote" 807, "Epiclone" 850, "Epiclone" 855 and "Epiclone" 8.
30, ELA128, DER331 and the like. Moreover, "Epicoat" 1001, "Epicoat" 1005, "Epiclon" 1050 etc. can be mentioned as a commercial item of a solid bisphenol A type epoxy resin.

For controlling the complex viscosity η ^* , the addition of a reactive diluent having a lower viscosity can be used together.

(Explanation of Reinforcing Fiber) As the reinforcing fiber used in the prepreg of the present invention, carbon fiber, glass fiber, aramid fiber, boron fiber, alumina fiber, silicon carbide fiber and the like can be used. In particular, carbon fibers having excellent specific strength and specific elastic modulus are preferably used. As the form of the reinforcing fibers, long fibers aligned in one direction, tows, woven fabrics, mats, knits, braids and the like are used.

In order to manufacture lightweight golf shafts, fishing rods, and other sports goods, it is preferable to use reinforcing fibers having a high elastic modulus in the prepreg so that a small amount of material can exhibit sufficient product rigidity. The tensile modulus of elasticity of such reinforcing fibers is preferably 400 GPa or more.

(Explanation of prepreg) By impregnating a reinforcing resin with a matrix resin, a prepreg as an intermediate base material of a fiber reinforced composite material is manufactured. As a method for producing a prepreg, there are methods such as a wet method in which a matrix resin is dissolved in a solvent such as methyl ethyl ketone or methanol to reduce its viscosity to impregnate it, and a hot melt method (dry method) in which it is reduced in viscosity by heating and impregnated.

The wet method is a method in which the reinforcing fiber is dipped in the epoxy resin composition solution and then pulled up, and the solvent is evaporated using an oven or the like to obtain a prepreg. In the hot melt method, a film in which an epoxy resin composition is coated on release paper or the like is first prepared, and then the film is laminated from both sides or one side of the reinforcing fiber, and a prepreg impregnated with the resin is produced by heating and pressing. Is the way to do it. The residual solvent is likely to remain in the prepreg prepared by the wet method, which may cause voids in the composite. Therefore, the hot melt method is preferable as the manufacturing method.

The strength and elastic modulus of the obtained composite are
It is almost determined by the content of reinforcing fibers. Therefore, when a certain amount of reinforcing fiber is contained, the weight of the product can be reduced while maintaining the performance of the composite and the final product substantially constant as the amount of the matrix resin contained is reduced. For this purpose, a prepreg having a high reinforcing fiber content is preferably used. In this case, the reinforcing fiber content of the prepreg is preferably 60 to 90% by weight,
Further, it is preferably 70 to 85% by weight. When using a prepreg with a high reinforcing fiber content,
By using the matrix resin of the present invention, it is possible to obtain excellent properties such as tackiness and drapeability which have not been obtained in the past.

(Description of Composite) Molding of a composite using a prepreg is usually carried out by laminating patterns obtained by cutting the prepreg and then heating and curing the resin while applying pressure to the laminate.

The method of applying heat and pressure includes a press molding method, an autoclave method, a bagging molding method, a sheet winding method, an internal pressure molding method and the like. Particularly for sports goods, the sheet winding method and the internal pressure molding method are preferable. Adopted.

The sheet winding method is a method of forming a cylindrical product by winding a prepreg around a cored bar such as a mandrel, and is suitable for manufacturing a rod-shaped body such as a stick such as a golf shaft or hockey. In particular,
To wrap the prepreg around the mandrel and to secure the prepreg so that it does not separate from the mandrel, and
In order to apply molding pressure to the prepreg by using the heat shrinkability of the tape, wrap a film tape (wrapping tape) on the outside of the prepreg, heat cure the resin, and then remove the core metal to form a cylindrical shape. Get the body.

In the internal pressure molding method, a prepreg is wound around the inner pressure imparting body made of a bag-shaped thermoplastic resin and set in a mold, and a high pressure fluid (for example, high pressure air) is introduced into the inner pressure imparting body and pressurized. At the same time, the molding is performed by heating the mold. Special shaped golf shaft, bat,
In particular, when molding a complicated shape such as a racket for tennis or badminton, the internal pressure molding method is preferably used.

Further, it is possible to prepare a composite by using the above-mentioned epoxy resin composition according to the present invention and the reinforcing fiber by a molding method such as a filament winding method, a pultrusion method, a resin injection molding method or the like. is there.

[0068]

The present invention will be described in more detail with reference to the following examples. The dynamic viscoelasticity, tackiness, drapeability, etc. were evaluated under the following conditions. A. Dynamic viscoelasticity Dynamic viscoelasticity was measured using a dynamic analyzer RDAII type manufactured by Rheometrics. The measurement was performed using a parallel plate having a radius of 25 mm, and the complex viscosity η ^* and the energy loss tan δ under the conditions of the measurement temperature of 50 ° C. and the measurement frequency of 0.5 Hz were obtained.

B. Tackiness of prepreg After the prepregs were pressure-bonded to each other, the peeling force was measured. This measurement method has many parameters such as load stress, velocity, and time. These may be appropriately determined in consideration of the usage state of the prepreg. Regarding the evaluation of tackiness in this example, an "Instron" 4201 universal material testing machine (manufactured by Instron Japan Co., Ltd.) was used as a measuring device, and the tackiness was measured under the following conditions.・ Sample: 50 × 50 mm ・ Load speed: 1 mm / min ・ Adhesive load: 0.12 MPa ・ Load time: 5 ± 2 sec ・ Peeling speed: 10 mm / min

C. Drapability of prepreg It is desirable to evaluate the drapability of prepreg by a method that can fully grasp the characteristics of the prepreg depending on the usage environment. Therefore, in the evaluation of the drape property in this example, the flexural modulus of the prepreg was measured. The method for measuring the flexural modulus was generally in accordance with JIS K7074 “Bending test method for fiber reinforced plastic”. However, since the prepreg is usually quite thin, it is necessary to set appropriate conditions. For evaluation in this example, "Instron" 4201 universal material testing machine (manufactured by Instron Japan Co., Ltd.) was used as a measuring device, and measurement was performed under the following conditions. -Sample: 85 mm (fiber direction) x 15 mm-Load speed: 5 mm / min-Span length: 40 mm (L / D = 40 / 0.06) -Indenter diameter: 4 mmφ

The tackiness and drapeability were measured by setting the conditions as described above. However, the conditions may be appropriately set depending on the environment in which the prepreg is used, the amount of reinforcing fiber used in the prepreg, the thickness, and the like. is necessary. Further, these evaluation methods can be used not only for prepregs but also for resin films and adhesive tapes.

D. Wrapability of prepreg around mandrel The wrapability of the prepreg around the mandrel was evaluated as follows. Temperature of prepreg is 23 ℃, humidity is 40
10% diameter and 1000 mm length under% RH atmosphere
The steel column was wrapped around the steel column such that the direction of alignment of the reinforcing fibers was at an angle of 45 ° with respect to the longitudinal direction of the column and left for 3 hours, and the winding state was observed. In the evaluation, the case where there is no lifting at the end point was marked with ◯, the case where partial lifting was observed was marked with Δ, and the case where lifting was found was marked with x.

Example 1 (1) Preparation of Matrix Resin Composition The following raw materials were kneaded using a kneader to prepare a matrix resin composition. Bisphenol A type epoxy resin: 35 parts by weight (Okaka Shell Epoxy Co., Ltd., "Epicoat" 828) Bisphenol A type epoxy resin: 30 parts by weight (Okaka Shell Epoxy Co., Ltd., "Epicoat" 1001) Phenol Novolac Type epoxy resin: 35 parts by weight (Yukaka Shell Epoxy Co., Ltd., "Epicote" 154) Polyester thermoplastic elastomer: 4 parts by weight (Toray DuPont Co., Ltd., "Hytrel" HTC2551) Polyvinyl formal resin: 4 Parts by weight ("Vinilec" K, manufactured by Chisso Corporation) Dicyandiamide: 4 parts by weight DCMU: 4 parts by weight

(2) Preparation of prepreg A resin film was prepared by applying the above resin composition onto release paper using a reverse roll coater. Next, carbon fiber “Torayca” M with elastic modulus of 435 GPa arranged in one direction
A resin film was laminated on both sides of 46J-6K (manufactured by Toray Industries, Inc.) and impregnated with the resin by heating and pressurizing (130 ° C., 0.4 MPa) to prepare a prepreg having a reinforcing fiber content of 76% by weight. The tackiness, drapeability, and wrapping property around the mandrel of this prepreg were good.

(3) Preparation of Fiber Reinforced Composite Material After cutting and stacking the prepreg, the temperature is 135 ° C. and the pressure is 0.1
Molding was performed in an autoclave for 2 hours under the condition of 3 MPa.
The wrap around the tack, drape and mandrel of this prepreg was good (see Table 1).

Example 2 (1) Preparation of matrix resin composition The following raw materials were kneaded using a kneader to prepare a matrix resin composition. Bisphenol A type epoxy resin: 35 parts by weight (Okaka Shell Epoxy Co., Ltd., "Epicoat" 828) Bisphenol A type epoxy resin: 30 parts by weight (Okaka Shell Epoxy Co., Ltd., "Epicoat" 1001) Phenol Novolac Type epoxy resin: 35 parts by weight (Yukaka Shell Epoxy Co., Ltd., "Epicote" 154) Polyester thermoplastic elastomer: 5 parts by weight (Toray DuPont Co., Ltd., "Hytrel" HTC2551) Polyethersulfone: 3 Parts by weight ("Victrex" PES5003P, manufactured by Mitsui Toatsu Chemicals, Inc.) Dicyandiamide: 4 parts by weight DCMU: 4 parts by weight

(2) Preparation of prepreg A prepreg was prepared in the same manner as in Example 1. The tackiness, drapeability and wrapping around the mandrel of the prepreg were good (see Table 1).

Example 3 (1) Preparation of Matrix Resin Composition The following raw materials were kneaded using a kneader to prepare a matrix resin composition. Bisphenol A-type epoxy resin: 30 parts by weight (Okaka Shell Epoxy Co., Ltd., "Epicoat" 828) Bisphenol A-type epoxy resin: 35 parts by weight (Okaka Shell Epoxy Co., Ltd., "Epicoat" 1001) Phenol Novolac Type epoxy resin: 35 parts by weight (Yukaka Shell Epoxy Co., Ltd., "Epicoat" 154) Polyester thermoplastic elastomer: 5 parts by weight (Toyobo Co., Ltd., "Perprene" S2001) Polyvinyl formal resin: 5 parts by weight Part (manufactured by Chisso Corporation, “Vinylec” K) Dicyandiamide: 4 parts by weight DCMU: 4 parts by weight

(2) Preparation of prepreg A prepreg was prepared in the same manner as in Example 1. The tackiness, drapeability and wrapping around the mandrel of the prepreg were good.

Example 4 (1) Preparation of Matrix Resin Composition The following raw materials were kneaded using a kneader to prepare a matrix resin composition. Bisphenol A-type epoxy resin: 30 parts by weight (Okaka Shell Epoxy Co., Ltd., "Epicoat" 828) Bisphenol A-type epoxy resin: 35 parts by weight (Okaka Shell Epoxy Co., Ltd., "Epicoat" 1001) Phenol Novolac Type epoxy resin: 35 parts by weight (Yukaka Shell Epoxy Co., Ltd., "Epicoat" 154) Polyamide thermoplastic elastomer: 10 parts by weight (ATOCHEM, "PEBAX" 4033) Dicyandiamide: 4 parts by weight DCMU: 4 parts by weight Department

(2) Preparation of prepreg A prepreg was prepared in the same manner as in Example 1. The tackiness, drapeability and wrapping around the mandrel of the prepreg were good.

Comparative Example 1 (1) Preparation of Matrix Resin Composition The following raw materials were kneaded using a kneader to prepare a matrix resin composition. Bisphenol A-type epoxy resin: 30 parts by weight (Okaka Shell Epoxy Co., Ltd., "Epicoat" 828) Bisphenol A-type epoxy resin: 35 parts by weight (Okaka Shell Epoxy Co., Ltd., "Epicoat" 1001) Phenol Novolac Type Epoxy resin: 35 parts by weight (Yukaka Shell Epoxy Co., Ltd., "Epicoat" 154) Polyvinyl formal resin: 10 parts by weight (Chisso Co., Ltd., "Vinilec" K) Dicyandiamide: 4 parts by weight DCMU: 4 parts by weight Department

(2) Preparation of prepreg A prepreg was prepared in the same manner as in Example 1. The tackiness of the prepreg was good. However, since the prepreg is stiff and the drape is poor, the wrapping around the mandrel is poor.

Comparative Example 2 (1) Preparation of Matrix Resin Composition The following raw materials were kneaded using a kneader to prepare a matrix resin composition. Bisphenol A-type epoxy resin: 30 parts by weight (Okaka Shell Epoxy Co., Ltd., "Epicoat" 828) Bisphenol A-type epoxy resin: 35 parts by weight (Okaka Shell Epoxy Co., Ltd., "Epicoat" 1001) Phenol Novolac Type epoxy resin: 35 parts by weight (Yukaka Shell Epoxy Co., Ltd., "Epicoat" 154) Polyester thermoplastic elastomer: 5 parts by weight (Toray DuPont Co., Ltd., "Hytrel" HTC2551) Dicyandiamide: 4 parts by weight DCMU: 4 parts by weight

(2) Preparation of prepreg A prepreg was prepared in the same manner as in Example 1. The tackiness of the prepreg was weak and the handleability was poor. Moreover, since the tackiness was weak, the winding property around the mandrel was poor.

Comparative Example 3 (1) Preparation of Matrix Resin Composition The following raw materials were kneaded using a kneader to prepare a matrix resin composition. Bisphenol A-type epoxy resin: 30 parts by weight (Okaka Shell Epoxy Co., Ltd., "Epicoat" 828) Bisphenol A-type epoxy resin: 35 parts by weight (Okaka Shell Epoxy Co., Ltd., "Epicoat" 1001) Phenol Novolac -Type epoxy resin: 35 parts by weight (Yukaka Shell Epoxy Co., Ltd., "Epicoat" 154) Dicyandiamide: 4 parts by weight DCMU: 4 parts by weight

(2) Preparation of prepreg A prepreg was prepared in the same manner as in Example 1. The tackiness of the prepreg was weak and the handleability was poor. Moreover, since the tackiness was weak, the winding property around the mandrel was poor.

[0088]

[Table 1]

[0089]

As described above, according to the present invention,
By using a prepreg that uses a matrix resin that has a dynamic viscoelasticity in a specific range, it is possible to achieve both a high level of tackiness and drapeability of the prepreg. A highly efficient, lightweight, high-strength composite can be produced with good workability.

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Claims (8)

[Claims] 1. A reinforcing fiber and a matrix resin,
The matrix resin is a thermosetting resin, and the complex viscosity η ^{* of the} matrix resin in dynamic viscoelasticity measurement at a measurement frequency of 0.5 Hz and 50 ° C. is 200 to 2,000 P.
The energy loss tan δ is 0.3 in the range of a · s.
A prepreg characterized by being in the range of ~ 5. 2. The prepreg according to claim 1, wherein the reinforcing fiber content is in the range of 70 to 85% by weight. 3. The prepreg according to claim 1 or 2, wherein the matrix resin is an epoxy resin composition. 4. The epoxy resin composition, wherein the matrix resin is at least (1) epoxy resin (2) curing agent (3) organic polymer compound.
Prepreg according to any one of. 5. The prepreg according to claim 1, wherein the reinforcing fibers are carbon fibers. 6. The prepreg according to claim 1, wherein the tensile elastic modulus of the reinforcing fiber is 400 GPa or more. 7. The prepreg according to any one of claims 1 to 6, wherein the reinforcing fibers include fiber bundles that are aligned in one direction. 8. A composite obtained by curing the prepreg according to claim 1.