JP5326435B2 - Epoxy resin composition, prepreg, fiber reinforced composite material, and method for producing fiber reinforced composite material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an epoxy resin composition capable of providing a fiber reinforced composite material excellent in heat resistance, elastic modulus, and elongation percentage, and to provide a prepreg using the epoxy resin composition and a method for producing the fiber reinforced composite material. <P>SOLUTION: The epoxy resin composition comprises [A] 30-55 pts.wt. of an amine type epoxy resin, [B] 45-70 pts.wt. of a bisphenol type epoxy resin, [C] 2-10 pts.wt. of diaminodiphenyl sulfone, [D] dicyandiamide or its derivative, [E] a urea compound, and [F] a thermoplastic resin. The reaction rate of the composition when it is cured at 150&deg;C for 1 hour is 90% or higher. The prepreg is obtained by impregnating a fiber substrate with the epoxy resin composition. The fiber reinforced composite material is obtained by curing the prepreg. The method for producing the fiber reinforced composite material includes curing the prepreg at 150-170&deg;C for 1 hour or less. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to an epoxy resin composition, a prepreg, and a method for producing a fiber reinforced composite material that can provide a fiber reinforced composite material excellent in heat resistance, elastic modulus, and elongation.

  More specifically, for example, various frames, pipes, shafts, wheels, and curved plates thereof, or shafts for golf clubs, fishing rods in airplanes, ships, automobiles, bicycles, and industrial machines such as pumps and brush cutters. Tubular bodies such as ski poles, badminton racket shafts, tent posts, or various sports / leisure products such as skis, snowboards, golf club heads, bicycle rims, bicycle wheels, or civil engineering and construction materials Further, the present invention relates to a method for producing a fiber-reinforced composite material that can be suitably used for repair and reinforcement thereof, a prepreg for obtaining the same, and an epoxy resin composition suitably used for obtaining the same.

  Fiber reinforced composite materials using carbon fibers, aramid fibers, etc. as reinforcing fibers make use of their high specific strength and specific modulus to make structural materials such as aircraft and automobiles, tennis rackets, golf shafts, fishing rods, bicycles, etc. Widely used in sports and general industrial applications. The fiber reinforced composite material manufacturing method uses a prepreg, which is a sheet-like intermediate material in which unreinforced matrix resin is impregnated into reinforcing fibers, and a method in which multiple sheets are laminated and then heat-cured, or placed in a mold A resin transfer molding method in which a liquid resin is poured into the reinforced fiber and heat-cured is used. Among these production methods, the method using a prepreg has an advantage that it is easy to obtain a high-performance fiber-reinforced composite material because the orientation of the reinforcing fibers can be strictly controlled and the design freedom of the laminated structure is high. As the matrix resin used for the prepreg, a thermosetting resin is mainly used from the viewpoint of heat resistance and productivity, and an epoxy resin is preferably used from the viewpoint of mechanical properties such as adhesion to reinforcing fibers. .

  In recent years, sports fiber-reinforced composite materials have been used for bicycle applications requiring weight reduction, that is, bicycle structures and bicycle parts. Among bicycle components, bicycle wheels are generally made of metal such as steel, aluminum, and aluminum alloys, but competition wheels are required to be lighter and carbon fiber. The fiber reinforced composite material is mainly used, and it is integrally formed with a disk wheel bonded with an aluminum honeycomb sandwiched in the center of the fiber reinforced composite plate and a fiber reinforced composite material with spokes having a constant cross-sectional shape. Things that have been developed have come to be developed. These wheels can be made lighter and have a structure that cannot be realized with conventional aluminum ones, and this increases the number of users mainly in competition applications.

  However, the fiber-reinforced composite wheel has a problem that was not found in the metal wheel. One of them is heat generated by friction between the brake shoe and the rim portion of the wheel during braking. In general, fiber reinforced composite materials used in conventional sports and general industrial applications do not have a high glass transition temperature to withstand such heat generation. Therefore, at the time of braking, the temperature of the fiber reinforced composite material becomes equal to or higher than the glass transition temperature, and the strength of the fiber reinforced composite material is lowered and deformed.

  Moreover, since the bicycle wheel is subjected to a load from the rider, an impact load from the road surface, etc., excellent strength and impact resistance are required.

  As a method for solving the above problem, a method for producing a bicycle wheel using an aluminum member on a brake contact surface and joined to a carbon fiber composite material member has been proposed (Patent Documents 1 and 2). Such a method is intended to solve these problems by devising the joining method of the aluminum member and the carbon fiber reinforced composite material member and the shape of the carbon fiber composite material member. However, in this case, improvement of heat resistance, strength, and impact resistance of the fiber reinforced composite material has not been studied, and such a method has limitations in improving these characteristics and is not sufficient.

  As a method for improving the heat resistance and compressive strength of the fiber-reinforced composite material, there is a method using a tetraglycidylamine type epoxy resin which has been used as an aircraft common material and a matrix resin of diaminodiphenylsulfone as a curing agent. However, when this resin composition is used as a matrix resin, the temperature required for heating when the prepreg is cured into a fiber reinforced composite material is as high as about 180 ° C., and further, the curing time takes 2 hours or more. Is not preferable for sports and general industries.

  As a method for improving the heat resistance and compressive strength of the fiber reinforced composite material and enabling molding at low temperature, there is a method in which an epoxy resin composition comprising a tetraglycidylamine type epoxy resin, dicyandiamide, and a urea compound is used as a matrix resin. Yes (Patent Document 3). In this method, a fiber reinforced composite material is produced at 100 to 140 ° C. However, the elongation of the cured product obtained from this resin composition is low, and when this is used as a matrix resin, the resulting fiber-reinforced composite material has low impact resistance, which is not preferable for bicycle parts. Moreover, when this fiber strength composite material is shape | molded at 100-140 degreeC, hardening of an epoxy resin composition is not completed. For this reason, since the hardening of an epoxy resin composition advances with the heat | fever at the time of braking after preparation and the obtained fiber reinforced composite material is distorted, it is unpreferable.

There is also a method in which an epoxy resin composition comprising a glycidylamine type epoxy resin, dicyandiamide, diaminodiphenylsulfone, a urea compound, or the like is used as a matrix resin (Patent Document 4). In this method, the fiber reinforced composite material is molded at 90 to 130 ° C. However, also in this case, since the curing temperature is not sufficient, curing of the epoxy resin composition is not completed.
US Pat. No. 5,975,645 US Pat. No. 6,991,298 JP 2000-17090 A Japanese Patent Laid-Open No. 02-151623

  In view of the background of such prior art, the present invention provides an epoxy resin composition capable of providing a fiber-reinforced composite material excellent in heat resistance, elastic modulus and elongation, and a prepreg using such an epoxy resin composition. Furthermore, the present invention provides a method for producing a fiber-reinforced composite material obtained by curing such a prepreg.

  ADVANTAGE OF THE INVENTION According to this invention, the fiber reinforced composite material which can be used conveniently for bicycle components, especially the fiber reinforced composite material suitable for a bicycle wheel can be provided.

The present invention employs the following means in order to solve such problems. That is, the epoxy resin composition of the present invention contains the following [A] to [F], the reaction rate when cured at 150 ° C. for 1 hour is 90% or more, and cured when cured at 150 ° C. for 1 hour. The glass transition temperature of the product is 140 to 170 ° C., and the three-point bending deflection specified by the following (I) is 5 mm or more.
[A] Amine type epoxy resin 30 to 55 parts by weight with respect to 100 parts by weight of all epoxy resin components
[B] Bisphenol type epoxy resin 45 to 70 parts by weight with respect to 100 parts by weight of all epoxy resin components [C] Diaminodiphenylsulfone 2 to 9 parts by weight with respect to 100 parts by weight of all epoxy resin components [D] Dicyandiamide or a derivative thereof [E ] Urea compound [F] thermoplastic resin
(I) After defoaming the uncured epoxy resin composition in a vacuum, in a mold set to a thickness of 2 mm with a 2 mm thick “Teflon (registered trademark)” spacer, at 150 ° C. for 1 hour Cured to obtain a cured resin having a thickness of 2 mm. A test piece having a width of 10 mm and a length of 60 mm was cut out from the cured resin, and the length between spans was measured using an Instron universal testing machine (Instron). Is set to 32 mm, the crosshead speed is set to 2.5 mm / min, and three-point bending is performed according to JIS K7171 (1994), and the average value of the bending deflection amount at n = 5 is defined as the three-point bending deflection amount.
A preferred embodiment of such an epoxy resin composition is:
(1) The total amount of active hydrogen groups of the [C] component and the [D] component is in the range of 0.6 to 1.0 equivalent with respect to 1 equivalent of epoxy groups of all epoxy resin components,
(2) 1 to 3 parts by weight of the [E] component with respect to 100 parts by weight of all epoxy resin components,
(3) The epoxy resin composition has a three-point bending elastic modulus specified by the following (II) of 3.5 GPa or more.
(II) After defoaming the uncured epoxy resin composition in a vacuum, in a mold set to a thickness of 2 mm with a 2 mm thick “Teflon (registered trademark)” spacer, at 150 ° C. for 1 hour Cured to obtain a cured resin having a thickness of 2 mm. A test piece having a width of 10 mm and a length of 60 mm was cut out from the cured resin, and the length between spans was measured using an Instron universal testing machine (Instron). Is set to 32 mm, the crosshead speed is set to 2.5 mm / min, and three-point bending is performed according to JIS K7171 (1994), and an average value of bending elastic modulus at n = 5 is defined as a three-point bending deflection amount.

  The prepreg of the present invention is characterized by impregnating a fiber base material with such an epoxy resin composition.

  Moreover, the fiber reinforced composite material of the present invention is obtained by curing the prepreg.

A preferred embodiment of the fiber-reinforced composite material of the present invention is:
(1) A prepreg formed by impregnating a fiber base material with an epoxy resin composition containing the above [A] to [F] and having a reaction rate of 90% or more when cured at 150 ° C. for 1 hour is cured. A fiber reinforced composite material, wherein the fiber reinforced composite material constitutes a bicycle part;
(2) The bicycle part is a bicycle wheel;
(3) The glass transition temperature of the cured product when the epoxy resin composition is cured at 150 ° C. for 1 hour is 140 to 170 ° C., and the three-point bending deflection specified in (I) above is 5 mm or more,
(4) The epoxy resin composition has a three-point bending elastic modulus specified by (II) above of 3.5 GPa or more.

  The method for producing a fiber-reinforced composite material of the present invention is characterized in that the prepreg is cured at 150 to 170 ° C. under curing conditions within 1 hour.

  According to the present invention, it is possible to provide a fiber-reinforced composite material having excellent heat resistance, elastic modulus, compressive strength, impact resistance, and the like, so that it is suitably used as a bicycle component, particularly a bicycle wheel.

  The present invention has been intensively studied on the above-mentioned problems, that is, an epoxy resin composition that can provide a fiber-reinforced composite material having excellent heat resistance, elastic modulus, and elongation, and an epoxy resin composition comprising specific components. However, when the blending was controlled so that the reaction rate when cured under specific curing conditions was within a specific range, it was found that such problems could be solved all at once.

That is, the epoxy resin composition of the present invention is an epoxy resin composition containing a predetermined amount of the following [A] to [F]. Moreover, in the range which does not lose the effect of this invention, you may contain epoxy resins other than [A]-[F], and another component.
[A] Amine type epoxy resin 30 to 55 parts by weight with respect to 100 parts by weight of all epoxy resin components
[B] Bisphenol type epoxy resin 45 to 70 parts by weight with respect to 100 parts by weight of all epoxy resin components [C] Diaminodiphenylsulfone 2 to 9 parts by weight with respect to 100 parts by weight of all epoxy resin components [D] Dicyandiamide or a derivative thereof [E ] Urea compound [F] Thermoplastic resin In the epoxy resin composition of the present invention, the component [A] is an amine type epoxy resin and an epoxy resin contained in the epoxy resin composition of the present invention (hereinafter referred to as all epoxy resin components). ) It is necessary to include 30 to 55 parts by weight of 100 parts by weight, and preferably 40 to 50 parts by weight. An amine-type epoxy resin refers to an epoxy resin having at least one amino group bonded to at least two glycidyl groups in the molecule, and having such a structure has a crosslinked structure having a high crosslinking density when a cured product is formed. Therefore, characteristics with high heat resistance and high elastic modulus can be obtained. When the blending amount of the component [A] is less than 30 parts by weight, the crosslink density of the cured product is low, resulting in insufficient heat resistance and elastic modulus. Moreover, when this compounding quantity exceeds 55 weight part, the crosslinking density of hardened | cured material becomes high too much, and although heat resistance and elastic modulus of hardened | cured material are enough, elongation is insufficient.
As such an amine type epoxy resin, for example, tetraglycidyldiaminodiphenylmethane, triglycidylaminophenol, triglycidylaminocresol, tetraglycidylxylylenediamine, halogens thereof, alkyl-substituted products, hydrogenated products, and the like can be used. .

  Examples of the tetraglycidyldiaminodiphenylmethane include “Sumiepoxy (registered trademark)” ELM434 (manufactured by Sumitomo Chemical Co., Ltd.), YH434L (manufactured by Tohto Kasei Co., Ltd.), and “jER (registered trademark)” 604 (Japan Epoxy Resin Co., Ltd.). ), “Araldide (registered trademark)” MY720, MY721 (manufactured by Huntsman Advanced Materials), etc. can be used. As triglycidylaminophenol or triglycidylaminocresol, “Sumiepoxy (registered trademark)” ELM100, ELM120 (manufactured by Sumitomo Chemical Co., Ltd.), “Araldide (registered trademark)” MY0500, MY0510, MY0600 (Huntsman Advanced Materials) And “jER (registered trademark)” 630 (Japan Epoxy Resin Co., Ltd.) and the like can be used. As tetraglycidylxylylenediamine and hydrogenated products thereof, “TETRAD (registered trademark)”-X, “TETRAD (registered trademark)”-C (manufactured by Mitsubishi Gas Chemical Co., Inc.) and the like can be used.

  In the epoxy resin composition of the present invention, the [B] component needs to contain 45 to 70 parts by weight, preferably 50 to 60 parts by weight, of 100 parts by weight of the total epoxy resin component of the bisphenol type epoxy resin. When the blending amount of the component [B] is less than 45 parts by weight, the cured product has sufficient heat resistance, but the elongation is insufficient. Moreover, when this compounding quantity exceeds 70 weight part, although elongation is enough, heat resistance is insufficient. Here, the bisphenol type epoxy resin is obtained by glycidylation of two phenolic hydroxyl groups of a bisphenol compound.

  The [B] component is not particularly limited as long as it is a bisphenol-type epoxy resin, and is bisphenol A-type, bisphenol F-type, bisphenol AD-type, bisphenol S-type, or halogens, alkyl-substituted products of these bisphenols, water Accessories are used. Moreover, not only a monomer but the high molecular weight body which has several repeating units can also be used conveniently.

  As commercial products of such bisphenol A type epoxy resins, jER825, jER828, jER834, jER1001, jER1002, jER1003, jER1003F, jER1004, jER1004AF, jER1005F, jER1006FS, jER1007, jER1009, jER1010 (above, Japan Epoxy Resins Co., Ltd.) "jER" includes the company's registered trademark (hereinafter the same). Examples of the brominated bisphenol A type epoxy resin include jER505, jER5050, jER5051, jER5054, jER5057 (manufactured by Japan Epoxy Resin Co., Ltd.) and the like. Examples of commercially available hydrogenated bisphenol A type epoxy resins include ST5080, ST4000D, ST4100D, and ST5100 (manufactured by Tohto Kasei Co., Ltd.).

  Commercially available products of the bisphenol F type epoxy resin include jER806, jER807, jER4002P, jER4004P, jER4007P, jER4009P, jER4010P (above made by Japan Epoxy Resin Co., Ltd.), Epototo YDF2001, Epototo YDF2004 (above made by Toto Kasei Co., Ltd.) "Epototo" is a registered trademark of the company). Examples of the tetramethylbisphenol F type epoxy resin include YSLV-80XY (manufactured by Nippon Steel Chemical Co., Ltd.).

  Examples of the bisphenol S-type epoxy resin include “Epiclon (registered trademark)” EXA-154 (manufactured by Dainippon Printing Chemical Co., Ltd.).

Of these, bisphenol A type epoxy resins and bisphenol F type epoxy resins are preferred because of a good balance between elastic modulus, toughness and heat resistance.
The average epoxy equivalent of the [B] component bisphenol-type epoxy resin is preferably 300 to 2,000, more preferably 500 to 1,000. When the average epoxy equivalent of the [B] component is less than 300, the crosslink density becomes too high, so that the heat resistance of the cured product is sufficient, but the elongation decreases. On the other hand, when the average epoxy equivalent exceeds 2000, the crosslinking density becomes too low, and the elongation of the cured product is sufficient, but the heat resistance is insufficient. Such an average epoxy equivalent can be determined by, for example, a known titration test as described in JIS K7236 (1995). However, when a plurality of epoxy resins having known epoxy equivalents are used in combination, the average epoxy equivalent can be estimated as follows. For example, the calculation method will be described by taking as an example the case of using three types of epoxy resins together. An epoxy resin X with an epoxy equivalent of Ex (g / eq) is Wx parts by weight, an epoxy resin Y with an epoxy equivalent of Ey (g / eq) is Wy parts by weight, and an epoxy resin Z with an epoxy equivalent of Ez (g / eq). When blending Wz parts by weight, the average epoxy equivalent is determined by the following formula.

Average epoxy equivalent = (Wx + Wy + Wz) / (Wx / Ex + Wy / Ey + Wz / Ez)
Controlling such that the average epoxy equivalent of the bisphenol type epoxy resin of the [B] component is in the range of 300 to 2000 may use an epoxy resin compound in such a range, or a plurality of epoxy having different epoxy equivalents. It can also be achieved by appropriately mixing resin compounds.

In the following, (sometimes abbreviated as later DDS) [C] component diaminodiphenylsulfone of the epoxy resin composition of the present invention are formulated as an epoxy resin curing agent. Such component [C] is required to be from 2 to 9 parts by weight per 100 parts by weight of total epoxy resin component is preferably 4 to 8 parts by weight. By blending the [C] component in the epoxy resin composition within this range, the elastic modulus can be improved without decreasing the elongation of the cured resin. Further, the reinforcing fiber and the matrix resin are more firmly bonded. When the blending amount is less than 2 parts by weight, the blended effect of the cured product is not recognized, which is not preferable. On the other hand, when the blending amount exceeds 9 parts by weight, the elastic modulus is sufficient, but the elongation is lowered, which is not preferable.

  DDS is a compound belonging to an aromatic amine curing agent, and in the present invention, fine particles are used. In DDS, there are structural isomers depending on the substitution position of the amino group on the aromatic ring. In the present invention, any isomer can be used, but by selecting the type of isomer, matrix resin, And the properties of the resulting composite material can be controlled. For example, when 3,3′-DDS is used, the elastic modulus is improved as compared with the case where 4,4′-DDS is used.

  Moreover, the dicyandiamide or its derivative of [D] component of the epoxy resin composition of this invention is also an epoxy resin hardening | curing agent. Such a [D] component is excellent in the balance of curability at low temperature, elastic modulus and elongation, and is excellent in the storage stability of the resin composition. Such a dicyandiamide derivative is obtained by bonding various compounds to dicyandiamide, and includes a reaction product with an epoxy resin, a reaction product with a vinyl compound or an acrylic compound. It is preferable that the compounding quantity of this [D] component is 1-10 weight part with respect to 100 weight part of all the epoxy resin components from a viewpoint of heat resistance or a mechanical characteristic. When the blending amount of the [D] component is less than 1 part by weight, the crosslink density of the cured product is not sufficient, and the elastic modulus is insufficient. When the blending amount exceeds 10 parts by weight, the cross-linking density of the cured product becomes too high, so that the plastic deformation ability becomes small and the elongation is inferior.

  Examples of such commercially available dicyandiamide include DICY-7 and DICY-15 (manufactured by Japan Epoxy Resin Co., Ltd.).

Furthermore, the total amount of the [C] and [D] components of the epoxy resin composition of the present invention is in the range of 0.6 to 1.0 equivalent of active hydrogen groups with respect to 1 equivalent of epoxy groups of all epoxy resin components. It is preferable to include an amount, and more preferably to include an amount in the range of 0.7 to 0.9 equivalent. Here, the active hydrogen group means a functional group capable of reacting with the epoxy group of the [C] and [D] components, and when the active hydrogen group is less than 0.6 equivalent, the reaction rate of the cured product, In some cases, the heat resistance and the elastic modulus are insufficient, and the glass transition temperature and strength of the fiber reinforced composite material may be insufficient. When the active hydrogen group exceeds 1.0 equivalent, the reaction rate, glass transition temperature, and elastic modulus of the cured product are sufficient, but the plastic deformation ability is insufficient, so that the impact resistance of the fiber reinforced composite material is low. There may be a shortage.
Such an epoxy resin curing agent may be used in combination with diaminodiphenylsulfone, dicyandiamide or a derivative thereof, and other epoxy resin curing agents other than these as long as the effects of the present invention are not lost. Other epoxy resin curing agents include aromatic amines, amines such as alicyclic amines, acid anhydrides, polyaminoamides, organic acid hydrazides, isocyanates, and the like.

    Moreover, the urea compound of the [E] component of the epoxy resin composition of this invention needs to be mix | blended as a curing catalyst of an epoxy resin. Such an [E] component is preferably included in an amount of 1 to 3 parts by weight, more preferably 1.5 to 3 parts by weight, based on 100 parts by weight of the total epoxy resin component.

  When the compounding quantity of this urea compound is less than 1 weight part, reaction does not fully advance and the elasticity modulus and heat resistance of hardened | cured material are insufficient. In addition, when the blending amount of the urea compound exceeds 3 parts by weight, the self-polymerization reaction of the epoxy resin inhibits the reaction between the epoxy resin and the curing agent diaminodiphenylsulfone, dicyandiamide or a derivative thereof. The toughness is insufficient and the elastic modulus is also lowered.

  Examples of such urea compounds include N, N-dimethyl-N ′-(3,4-dichlorophenyl) urea, toluenebis (dimethylurea), 4,4′-methylenebis (phenyldimethylurea), and 3-phenyl-1 , 1-dimethylurea can be used.

  Commercially available products of such urea compounds include DCMU99 (manufactured by Hodogaya Chemical Co., Ltd.), Omicure 24, Omicure 52, Omicure 94 (above CVCCS Specialty Chemicals, Inc.).

  As such an epoxy resin curing catalyst, a urea compound and other epoxy resin curing catalyst other than these may be used in combination as long as the effects of the present invention are not lost. Other epoxy resin curing catalysts include tertiary amines and salts thereof, imidazole and salts thereof, Lewis acids and Bronsted acids and salts thereof, and the like.

  Furthermore, the epoxy resin composition according to the present invention includes improvements such as control of rheological properties when the resin is in an uncured state, improvement in rigidity and toughness of the matrix resin, tack control of the prepreg, and improvement in adhesion between the reinforcing fiber and the matrix resin. In order to bring about an effect, it is necessary to contain a thermoplastic resin as the [F] component, and it is preferably contained in an amount of 0.1 to 10 parts by weight, more preferably 0. 3 to 7 parts by weight, particularly preferably 1 to 5 parts by weight. When the amount of the thermoplastic resin is less than 0.1 parts by weight, the above effect cannot be obtained sufficiently, and when it exceeds 10 parts by weight, the viscosity of the epoxy resin becomes too high, so that the processability is remarkably high. Getting worse.

As such a thermoplastic resin, a thermoplastic resin soluble in an epoxy resin, organic particles such as rubber particles and thermoplastic resin particles, and the like can be blended. As the thermoplastic resin soluble in such an epoxy resin, a thermoplastic resin having a hydrogen bonding functional group that can be expected to improve the adhesion between the resin and the reinforcing fiber is preferably used.
As such a thermoplastic resin that is soluble in an epoxy resin and has a hydrogen bonding functional group, a thermoplastic resin having an alcoholic hydroxyl group, a thermoplastic resin having an amide bond, or a thermoplastic resin having a sulfonyl group can be used.
Examples of the thermoplastic resin having an alcoholic hydroxyl group include polyvinyl acetal resins such as polyvinyl formal and polyvinyl butyral, polyvinyl alcohol, and phenoxy resins. Examples of the thermoplastic resin having an amide bond include polyamide, polyimide, Polyvinyl pyrrolidone can be mentioned, and as a thermoplastic resin having a sulfonyl group, polysulfone can be mentioned. 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.

  Examples of commercially available thermoplastic resins soluble in epoxy resins and having hydrogen bonding functional groups include Denkabutyral and “Denka Formal (registered trademark)” (manufactured by Denki Kagaku Kogyo Co., Ltd.), “ “Vinylec (registered trademark)” (manufactured by Chisso Corporation), “UCAR (registered trademark)” PKHP (manufactured by Union Carbide) as a phenoxy resin, “Macromelt (registered trademark)” (manufactured by Henkel Hakusui Co., Ltd.) as a polyamide resin ), “Amilan (registered trademark)” CM4000 (manufactured by Toray Industries, Inc.), “Ultem (registered trademark)” (manufactured by General Electric) as polyimide, “Matrimid (registered trademark)” 5218 (manufactured by Ciba), and polysulfone “Victrex (registered trademark)” (manufactured by Mitsui Chemicals, Inc.), “UD L (registered trademark) "(manufactured by Union Carbide Corporation), as polyvinylpyrrolidone," Luviskol (registered trademark) "can be exemplified (BASF Japan Ltd.).

  In addition, the acrylic resin has high compatibility with the epoxy resin, and is preferably used for controlling the viscoelasticity. Examples of commercially available acrylic resins include “Dianal (registered trademark)” BR series (manufactured by Mitsubishi Rayon Co., Ltd.), “Matsumoto Microsphere (registered trademark)” M, M100, M500 (Matsumoto Yushi Seiyaku Co., Ltd.) Manufactured).

  The epoxy resin composition according to the present invention can contain rubber particles. As such 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 from the viewpoint of handleability and the like.

  Commercially available products of the crosslinked rubber particles include FX501P (made by Nippon Synthetic Rubber Industry) made of a crosslinked product of carboxyl-modified butadiene-acrylonitrile copolymer, CX-MN series made by acrylic rubber fine particles (made by Nippon Shokubai Co., Ltd.). ), YR-500 series (manufactured by Toto Kasei Co., Ltd.) and the like can be used.

  Commercially available core-shell rubber particles include, for example, “Paraloid (registered trademark)” EXL-2655 (manufactured by Kureha Chemical Co., Ltd.), acrylic ester / methacrylic ester, composed of a butadiene / alkyl methacrylate / styrene copolymer. "STAPHYLOID (registered trademark)" AC-3355 made of a copolymer, TR-2122 (manufactured by Takeda Pharmaceutical Co., Ltd.), "PARALOID (registered trademark)" EXL made of a butyl acrylate / methyl methacrylate copolymer -2611, EXL-3387 (manufactured by Rohm & Haas), “Kane Ace (registered trademark)” MX series (manufactured by Kaneka Corporation), and the like can be used.

  As the thermoplastic resin particles, polyamide particles and polyimide particles are preferably used, and as commercially available products of polyamide particles, SP-500 (manufactured by Toray Industries, Inc.), “Orgasol (registered trademark)” (manufactured by Arkema), etc. Can be used.

  In addition, the epoxy resin composition of the present invention includes the [A] component or the [A] component for the purpose of improving workability by adjusting viscoelasticity when uncured or improving the elastic modulus and heat resistance of the cured resin. B] An epoxy resin other than the component can be added as long as the effects of the present invention are not lost. These may be added in combination of not only one type but also a plurality of types. Specific examples include phenol novolac type epoxy resins, cresol novolac epoxy resins, resorcinol type epoxy resins, phenol aralkyl type epoxy resins, dicyclopentadiene type epoxy resins, epoxy resins having a biphenyl skeleton, and urethane-modified epoxy resins.

  Commercially available products of such phenol novolac type epoxy resins include “Epicoat (registered trademark)” 152, “Epicoat (registered trademark)” 154 (manufactured by Japan Epoxy Resin Co., Ltd.), and “Epicron (registered trademark)” N-740. "Epiclon (registered trademark)" N-770, "Epiclon (registered trademark)" N-775 (manufactured by Dainippon Ink & Chemicals, Inc.), and the like.

  Examples of commercially available cresol novolac epoxy resins include “Epicron (registered trademark)” N-660, “Epicron (registered trademark)” N-665, “Epicron (registered trademark)” N-670, and “Epicron (registered trademark)”. “N-673”, “Epicron (registered trademark)” N-695 (above, manufactured by Dainippon Ink & Chemicals, Inc.), EOCN-1020, EOCN-102S, EOCN-104S (above, manufactured by Nippon Kayaku Co., Ltd.) ) And the like.

  Specific examples of the resorcinol type epoxy resin include “Denacol (registered trademark)” EX-201 (manufactured by Nagase ChemteX Corporation).

  Commercially available dicyclopentadiene type epoxy resins include “Epicron (registered trademark)” HP7200, “Epicron (registered trademark)” HP7200L, “Epicron (registered trademark)” HP7200H (above, Dainippon Ink & Chemicals, Inc.) , Tactix 558 (manufactured by Huntsman Advanced Materials), XD-1000-1L, XD-1000-2L (manufactured by Nippon Kayaku Co., Ltd.), and the like.

  As commercially available products of epoxy resins having a biphenyl skeleton, “Epicoat (registered trademark)” YX4000H, “Epicoat (registered trademark)” YX4000, “Epicoat (registered trademark)” YL6616 (above, manufactured by Japan Epoxy Resins Co., Ltd.), NC-3000 (made by Nippon Kayaku Co., Ltd.) etc. are mentioned.

  Examples of commercially available urethane and isocyanate-modified epoxy resins include AER4152 (produced by Asahi Kasei Epoxy Co., Ltd.) and ACR1348 (produced by Asahi Denka Co., Ltd.) having an oxazolidone ring.

  For preparing the epoxy resin composition of the present invention, a kneader, a planetary mixer, a three-roll extruder, a twin-screw extruder, or the like is preferably used. The epoxy resin [A] component, the [B] component, and the thermoplastic resin [F] component are added, and the temperature of the epoxy resin is raised to an arbitrary temperature of 100 to 180 ° C. while stirring, and the [A] component, [B] ] Component and [F] component are dissolved. After obtaining a transparent viscous liquid in which these are dissolved, the temperature is preferably lowered to a temperature of 100 ° C. or lower, more preferably 80 ° C. or lower with stirring, and the diaminodiphenyl sulfone of the [C] component and the [D] component are reduced. A method of adding and kneading dicyandiamide or a derivative thereof and a urea compound as the component [E] is preferably used because of excellent storage stability of the resin composition.

  The cured product is produced as follows. After the defoaming of the epoxy resin composition in a vacuum, the void was removed by curing for 1 hour at a temperature of 150 ° C. in a mold set to a thickness of 2 mm with a 2 mm thick “Teflon (registered trademark)” spacer. No plate-like cured product is obtained. When the curing temperature is less than 150 ° C., the reaction rate of the cured product is less than 90%, which is not preferable. In addition, when the curing temperature exceeds 150 ° C., a large amount of energy is required to produce a cured product, which is not preferable.

In the epoxy resin composition of the present invention, it is important that the reaction rate when cured at 150 ° C. for 1 hour (hereinafter simply referred to as reaction rate) is 90% or more, preferably 95% or more. . When the reaction rate is less than 90%, the cured product is not preferable because it tends to deform when exposed to heat or light. In the present invention, the reaction rate refers to the reaction rate of the glycidyl group in the epoxy resin component, and can be determined as follows. That is, it calculates from the area ratio of the absorbance of the benzene ring peak and the oxirane ring peak of the epoxy resin composition and the cured resin using an infrared spectrum. Specifically, using a Fourier transform infrared spectrophotometer and measuring the area of the absorbance of the epoxy resin composition and cured resin respective benzene ring peak (1510 cm ^-1) and oxirane ring peak (910 cm ^-1), For each, the area ratio of the oxirane ring to the benzene ring {(area of the oxirane ring peak) / (area of the peak of the benzene ring)} is obtained, and the reaction rate of the cured resin is obtained by the following formula.

Reaction rate = (1− (area ratio of cured resin) / (area ratio of epoxy resin composition)) × 100
In order for the reaction rate to be 90% or more, the total amount of the [C] component and the [D] component is not less than the amount at which the active hydrogen groups are 0.6 equivalents with respect to 1 equivalent of the epoxy groups of all epoxy resin components. In addition, the [E] component is preferably 1 part by weight or more with respect to 100 parts by weight of the total epoxy resin component.

The glass transition temperature of the cured product of such an epoxy resin composition may to be 140 to 170 ° C., more preferably from 0.99 ° C. to 160 ° C.. When the glass transition temperature is less than 140 ° C., the heat resistance of the fiber reinforced composite material is insufficient in a bicycle wheel or the like. In addition, when the glass transition temperature exceeds 170 ° C., the thermal stress remaining in the fiber reinforced composite material tends to increase or the cured product tends to become brittle, and the strength characteristics of the resulting fiber reinforced composite material may deteriorate. .

  Moreover, when this glass transition temperature is less than 140 degreeC, a glass transition temperature can be improved by performing the at least 1 or more method of the following adjustment method within the scope of the present invention.

  (1) Increase the component [A].

  (2) Decrease the epoxy equivalent of [B] component.

  (3) Decrease the [C] component.

  (4) Increase the total amount of the [C] component and the [D] component.

  (5) Increase the component [E].

  Furthermore, when the glass transition temperature exceeds 170 ° C., the glass transition temperature can be lowered by performing at least one of the following adjustment methods within the scope of the present invention.

  (1) Reduce [A] component.

  (2) Increasing the epoxy equivalent of [B] component.

  (3) Increase the component [C].

  (4) Reduce the total amount of the [C] component and the [D] component.

  (5) Decrease the [E] component.

Furthermore, the three-point bending elastic modulus of the cured product is preferably 3.5 GPa or more, and more preferably 3.7 GPa or more. When the three-point bending elastic modulus of the cured product is less than 3.5 GPa, the compression strength of the obtained fiber-reinforced composite material is lowered, which is not preferable.

  When the flexural modulus is less than 3.5 GPa, the flexural modulus can be set to 3.5 GPa or more by performing at least one of the following adjustment methods within the scope of the present invention. .

  (1) Increase the component [A].

  (2) Decrease the epoxy equivalent of [B] component.

  (3) Increase the component [C].

  (4) Increase the total amount of the [C] and [D] components.

  (5) Increase the component [E].

3 point bending deflection amount whether mow the cured product may as being 5mm or more, more preferably 7mm or more. When the three-point bending deflection of the cured product is less than 5 mm, the resulting fiber-reinforced composite material has low impact resistance, which is not preferable.

  When the bending deflection amount is less than 5 mm, the bending deflection amount can be set to 5 mm or more by performing at least one of the following adjustment methods within the scope of the present invention.

  (1) Reduce [A] component.

  (2) Increasing the epoxy equivalent of [B] component.

  (3) Reduce the total amount of the [C] and [D] components.

  (4) Reduce the [E] component.

The prepreg and the fiber reinforced composite material of the present invention are configured using reinforced fibers, but such reinforced fibers are not particularly limited, and are glass fiber, carbon fiber, aramid fiber, boron fiber, alumina fiber, carbonized fiber. Silicon fiber or the like is used. Two or more of these fibers may be mixed and used. Among these, it is preferable to use carbon fibers from which a lightweight and highly rigid fiber-reinforced composite material can be obtained.

  The form of the reinforcing fiber is not particularly limited, and for example, a long fiber aligned in one direction, a tow, a woven fabric, a mat, a knit, a braid, a short fiber chopped to a length of less than 10 mm, and the like are used. As used herein, long fibers refer to single fibers or fiber bundles that are substantially continuous for 10 mm or more. A short fiber is a fiber bundle cut to a length of less than 10 mm. In particular, an array in which reinforcing fiber bundles are aligned in a single direction is most suitable for applications that require a high specific strength and specific elastic modulus. Arrangements are also suitable for the present invention.

  The prepreg of the present invention is constituted by impregnating the fiber base material composed of the reinforcing fibers with the epoxy resin composition of the present invention. Examples of the impregnation method include 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 impregnation, and a hot melt method (dry method) in which the viscosity is reduced by heating and impregnation. it can.

  The wet method is a method in which the reinforcing fiber is immersed in a solution of the epoxy resin composition and then pulled up, and the solvent is evaporated using an oven or the like. The hot melt method is an epoxy resin composition whose viscosity is reduced by heating. A method of impregnating a fiber substrate made of reinforcing fibers directly, or a film in which an epoxy resin composition is once coated on a release paper or the like, and then producing the film from both sides or one side of the fiber substrate made of the reinforcing fibers This is a method in which a resin is impregnated into a fiber base material composed of the reinforcing fibers by stacking films and heating and pressing. The hot melt method is preferable because substantially no solvent remains in the prepreg.

The prepreg preferably has a reinforcing fiber amount per unit area of 70 to 200 g / m ² . When the amount of the reinforcing fibers is less than 70 g / m ^2, it is necessary to increase the number of laminated layers in order to obtain a predetermined thickness at the time of forming the fiber reinforced composite material, and the work may be complicated. On the other hand, when the amount of reinforcing fibers exceeds 200 g / m ² , the prepreg drapability tends to deteriorate. The fiber weight content is preferably 60 to 90% by weight, more preferably 65 to 85% by weight, and still more preferably 70 to 80% by weight. When the fiber weight content is less than 60% by weight, the amount of the resin is too large to obtain the advantages of the fiber reinforced composite material excellent in specific strength and specific elastic modulus, or when the fiber reinforced composite material is produced at the time of curing. The amount of heat generated may be too high. On the other hand, if the fiber weight content exceeds 90% by weight, poor resin impregnation may occur, and the resulting composite material may have many voids.

  After shaping and / or laminating the prepreg, the composite material according to the present invention is produced by a method of heat-curing the resin while applying pressure to the shaped product and / or laminate.

  As a method for applying heat and pressure, a press molding method, an autoclave molding method, a bagging molding method, a wrapping tape method, an internal pressure molding method, or the like can be appropriately used.

  The wrapping tape method is a method of winding a prepreg around a mandrel or other core metal to form a tubular body made of a fiber-reinforced composite material, and is a method suitable for producing a rod-shaped body such as a golf shaft or fishing rod. . More specifically, a prepreg is wound around a mandrel, a wrapping tape made of a thermoplastic 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 extracting a tube to obtain a tubular body.

  Also, the internal pressure molding method is to set a preform in which a prepreg is wound on an internal pressure applying body such as a tube made of a thermoplastic resin in a mold, and then introduce a high pressure gas into the internal pressure applying body to apply pressure. At the same time, the mold is heated and molded. This method is preferably used when molding a complicated shape such as a golf shaft, a bad, a racket such as tennis or badminton, or a bicycle wheel.

  As a manufacturing method of the fiber reinforced composite material of this invention, it is preferable to make it harden within 1 hour at 150-170 degreeC. When the curing temperature is less than 150 ° C., the reaction rate of the epoxy resin composition that is a matrix resin may be less than 90%, which is not preferable. Moreover, when exceeding 170 degreeC, since a lot of energy is needed, it is unpreferable. Furthermore, when the curing time exceeds 1 hour, a large amount of energy is required, which is not preferable.

  A fiber reinforced composite material obtained by curing a prepreg constituted by using the epoxy resin composition of the present invention as a matrix resin is suitably used for sports applications, general industrial applications, and aerospace applications. More specifically, in sports applications, it is used for golf shafts, fishing rods, tennis and badminton rackets, hockey sticks, and ski poles. In general industrial applications, structural materials for moving bodies such as automobiles, ships, and railway vehicles, drive shafts, leaf springs, windmill blades, pressure vessels, flywheels, paper rollers, roofing materials, cables, and repair reinforcement materials, etc. Used for. More preferably, it is used for bicycle parts and bicycle wheels.

  Hereinafter, the present invention will be described in more detail with reference to examples. Various physical properties were measured by the following methods. These physical properties were measured in an environment at a temperature of 23 ° C. and a relative humidity of 50% unless otherwise specified.

(1) Preparation of resin composition In kneader, a predetermined amount of components other than diaminodiphenylsulfone, dicyandiamide and its derivatives and urea compound are added, and the mixture is kneaded, heated to 160 ° C, and kneaded at 160 ° C for 1 hour. Thus, a transparent viscous liquid was obtained. The temperature was lowered while kneading to 80 ° C., and a predetermined amount of diaminodiphenylsulfone, dicyandiamide and derivatives thereof and a urea compound were added and kneaded to obtain an epoxy resin composition. The component blend ratios of the examples and comparative examples are as shown in Table 1. The molecular weight and the like of the raw materials used here are as shown below.
<Amine type epoxy resin>
Triglycidyl-p-amino-o-methylphenol ("SUMI Epoxy (registered trademark)" ELM100, epoxy equivalent: 106, manufactured by Sumitomo Chemical Co., Ltd.)
Tetraglycidyl diaminodiphenyl methane (“Sumiepoxy (registered trademark)” ELM434, manufactured by Sumitomo Chemical Co., Ltd., epoxy equivalent: 125)
<Bisphenol type epoxy resin>
-Bisphenol A type epoxy resin ("jER (registered trademark)" 828, epoxy equivalent: 189, manufactured by Japan Epoxy Resins Co., Ltd.)
-Bisphenol A type epoxy resin ("jER (registered trademark)" 1001, epoxy equivalent: 475, manufactured by Japan Epoxy Resins Co., Ltd.)
-Bisphenol A type epoxy resin ("jER (registered trademark)" 1009, epoxy equivalent: 3300, manufactured by Japan Epoxy Resins Co., Ltd.)
<Diaminodiphenylsulfone>
・ 4,4'-Diaminodiphenylsulfone ("Seika Cucca" -S, Wakayama Seika Kogyo Co., Ltd.)
<Dicyandiamide or its derivative>
・ Dicyandiamide (DICY7, manufactured by Japan Epoxy Resin Co., Ltd.)
<Urea compound>
DCMU99 (3- (3,4-dichlorophenyl) 1,1-dimethylurea, manufactured by Hodogaya Chemical Co., Ltd.)
<Thermoplastic resin>
・ "Vinylec (registered trademark)" E (polyvinyl formal, manufactured by Chisso Corporation)
(2) Measurement of flexural modulus and amount of flexure of resin-cured product After defoaming the uncured resin composition in vacuum, a mold set to a thickness of 2 mm with a 2 mm thick Teflon (registered trademark) spacer Inside, it hardened at the temperature as described in each Example and a comparative example for 1 hour, and the resin cured material of thickness 2mm was obtained. From this cured resin, a test piece having a width of 10 mm and a length of 60 mm was cut out, an Instron universal tester (Instron) was used, the span length was 32 mm, and the crosshead speed was 2.5 mm / min. Three-point bending was performed according to JIS K7171 (1994) to obtain a flexural modulus and a bending deflection. The number of samples was n = 5, and the average value was compared.
(3) Reaction rate measurement of resin cured product Using Fourier transform infrared spectrophotometer (IR Prestige-21: manufactured by Shimadzu Corporation), the epoxy resin composition and the benzene ring peak (1510 cm ⁻¹ ) of the resin cured product The absorbance area of the oxirane ring peak (910 cm ⁻¹ ) was measured to obtain the area ratio of the oxirane ring to the benzene ring. The area ratio of the oxirane ring to the benzene ring was determined from (the area of the oxirane ring peak) / (the area of the benzene ring peak). The reaction rate of the cured resin was calculated from (1- (area ratio of cured resin) / (area ratio of epoxy resin composition)) × 100.
(4) Measurement of glass transition temperature of resin cured product A sample having a width of 13 mm and a length of 50 mm was cut out from the plate-shaped resin cured product prepared according to (2) above using a diamond cutter. Using a dynamic viscoelasticity measuring device (Rheometer RDA2: manufactured by Rheometrics), the sample was heated at a rate of temperature increase of 5 ° C./min, and the storage elastic modulus was measured in a torsion mode with a frequency of 1.0 Hz. It was. The onset temperature of the storage elastic modulus at this time was defined as the glass transition temperature. The number of measurements was n = 3, and the average value was compared.
(5) Preparation of prepreg The resin composition prepared according to the above (1) was applied to a release paper using a reverse roll coater to prepare a resin film. Next, two resin films are placed on both sides of the carbon fiber on a carbon fiber “Torayca (registered trademark)” T700S (manufactured by Toray Industries, Inc., tensile elastic modulus: 230 GPa, tensile strength: 4900 MPa) aligned in one direction in a sheet shape. Then, the resin composition was impregnated by heating and pressing to prepare a T700S unidirectional prepreg having a carbon fiber weight of 125 g / m ² per unit area and a fiber weight content of 68%.
(6) Measurement of glass transition temperature of fiber reinforced composite material T700S unidirectional prepreg produced according to (5) above was laminated in one direction so as to have a 20-layer structure, and then each example and comparative example in an autoclave. And cured by heating and pressing at 0.3 MPa for 1 hour to prepare a fiber-reinforced composite material. A sample having a width of 13 mm and a length of 50 mm was cut out from the obtained fiber-reinforced composite material using a diamond cutter. Using a dynamic viscoelasticity measuring device (Rheometer RDA2: manufactured by Rheometrics), the sample was heated at a rate of temperature increase of 5 ° C./min, and the storage elastic modulus was measured in a torsion mode with a frequency of 1.0 Hz. It was. The onset temperature of the storage elastic modulus at this time was defined as the glass transition temperature. The number of measurements was n = 3, and the average value was compared.
(7) Measurement of compressive strength of fiber reinforced composite material A fiber reinforced composite material was produced in the same manner as in (6) above. A test piece was cut out from the obtained fiber-reinforced composite material with the shape and size of the A method test piece of JIS K7076, and the 0 ° compressive strength was measured. The number of measurements was n = 5, and the average value was obtained.
(8) Measurement of Charpy impact value of fiber reinforced composite material T700S unidirectional prepreg produced in accordance with (5) above was laminated in one direction so as to form a 30-layer structure, and then each example and comparative example in an autoclave. And cured by heating and pressing at 0.3 MPa for 1 hour to prepare a fiber-reinforced composite material having a thickness of 32 mm. A sample having a width of 10 mm and a length of 80 mm was cut out from the obtained fiber-reinforced composite material using a diamond cutter. This sample was subjected to a Charpy impact test in accordance with JIS K7077 to obtain a Charpy impact value. The number of samples was n = 5, and the average value was compared.

  The epoxy resin composition, prepreg and fiber reinforced composite material were prepared for each Example and Comparative Example by the above method, and the results of measuring the properties are summarized in Tables 1 and 2.

Example 1
As shown in Table 1, 35 parts of ELM100 as an amine type epoxy resin, 40 parts of jER828 as a bisphenol type epoxy resin and 25 parts of jER1001, 3 parts of Seikacure-S as diaminodiphenylsulfone, 5 parts of DICY7 as dicyandiamide or a derivative thereof An epoxy resin composition was prepared using 3 parts of DCMU99 as a urea compound and 4 parts of Vinylec E as a thermoplastic resin. The average epoxy equivalent of the bisphenol type epoxy resin component at this time is 300, and the total number of active hydrogen groups [C] and [D] with respect to 1 equivalent of the epoxy groups of all epoxy resin components (hereinafter abbreviated as the number of active hydrogen groups). ) Was 0.8 equivalents. The obtained epoxy resin composition was cured at 150 ° C. to obtain a cured resin. The reaction rate at this time was 100%. Moreover, the fiber reinforced composite material was produced at 150 degreeC using this epoxy resin composition. The properties of the cured resin and fiber reinforced composite material obtained from this epoxy resin composition were good as shown in Table 1.

(Example 2)
An epoxy resin composition was prepared in the same manner as in Example 1 except that 35 parts of ELM434 was used as the amine type epoxy resin. The average epoxy equivalent of the bisphenol-type epoxy resin component at this time was 300, and the number of active hydrogen groups was 0.8 equivalent. The obtained epoxy resin composition was cured at 150 ° C. to obtain a cured resin. The reaction rate at this time was 100%. Moreover, the fiber reinforced composite material was produced at 150 degreeC using this epoxy resin composition. The properties of the cured resin and fiber reinforced composite material obtained from this epoxy resin composition were good as shown in Table 1.

(Example 3)
An epoxy resin composition was prepared in the same manner as in Example 2 except that 50 parts of ELM434 was used as the amine type epoxy resin and 25 parts of jER828 and 25 parts of jER1001 were used as the bisphenol type epoxy resin. On the other hand, the average epoxy equivalent of the bisphenol type epoxy resin component at this time was 332. The obtained epoxy resin composition was cured at 150 ° C. to obtain a cured resin. The reaction rate at this time was 98%, and the number of active hydrogen groups was 0.8 equivalent. The bending elastic modulus and glass transition temperature of the cured resin were improved as compared with Example 2. Moreover, the fiber reinforced composite material was produced at 150 degreeC using this epoxy resin composition. Table 1 shows the characteristics of the cured resin and the fiber-reinforced composite material obtained from this epoxy resin composition. The Charpy impact value of the obtained fiber reinforced composite material was slightly lower than that of Example 2, but was good, and the glass transition temperature and 0 ° compressive strength were improved as compared with Example 2.

Example 4
An epoxy resin composition was prepared in the same manner as in Example 3, except that 30 parts of jER828 and 20 parts of jER1009 were used as the bisphenol type epoxy resin. The average epoxy equivalent of the bisphenol type epoxy resin component at this time was 1433. The obtained epoxy resin composition was cured at 150 ° C. to obtain a cured resin. The reaction rate at this time was 98%, and the number of active hydrogen groups was 0.8 equivalent. Moreover, the fiber reinforced composite material was produced at 150 degreeC using this epoxy resin composition. Table 1 shows the characteristics of the cured resin and the fiber-reinforced composite material obtained from this epoxy resin composition. Although the glass transition temperature of this cured resin was lower than that in Example 3, it was at a level causing no problem in practice, and the bending elastic modulus and the amount of bending deflection were improved as compared with Example 3. Further, the 0 ° compressive strength and the Charpy impact value of this fiber reinforced composite material were both improved as compared with Example 3.

(Example 5)
An epoxy resin composition was prepared in the same manner as in Example 3 except that 5 parts of Seikacure-S was used as diaminodiphenylsulfone. The average epoxy equivalent of the bisphenol-type epoxy resin component at this time was 332, and the number of active hydrogen groups was 0.8 equivalent. The obtained epoxy resin composition was cured at 150 ° C. to obtain a cured resin. The reaction rate at this time was 95%. Moreover, the fiber reinforced composite material was produced at 150 degreeC using this epoxy resin composition. Table 1 shows the characteristics of the cured resin and the fiber-reinforced composite material obtained from this epoxy resin composition. Compared to Example 3, the flexural modulus of the cured resin was improved. As a result, the 0 ° compressive strength of the fiber-reinforced composite material was also improved.

(Example 6)
An epoxy resin composition was prepared in the same manner as in Example 3 except that 9 parts of Seikacure-S was used as diaminodiphenylsulfone. The average epoxy equivalent of the bisphenol-type epoxy resin component at this time was 332, and the number of active hydrogen groups was 0.9 equivalent. The obtained epoxy resin composition was cured at 150 ° C. to obtain a cured resin. The reaction rate at this time was 92%. Moreover, the fiber reinforced composite material was produced at 150 degreeC using this epoxy resin composition. Table 1 shows the characteristics of the cured resin and the fiber-reinforced composite material obtained from this epoxy resin composition. Compared with Example 3, the glass transition temperature of this cured resin was lowered, but the flexural modulus was greatly improved, and the glass transition temperature of the fiber reinforced composite material was lowered and the 0 ° compression strength was also greatly improved. .

(Example 7)
An epoxy resin composition was prepared in the same manner as in Example 5 except that 25 parts of jER828, 15 parts of jER1001, and 10 parts of jER1009 were used as the bisphenol type epoxy resin. The average epoxy equivalent of the bisphenol-type epoxy resin component at this time was 897, and the number of active hydrogen groups was 0.9 equivalent. The obtained epoxy resin composition was cured at 150 ° C. to obtain a cured resin. The reaction rate at this time was 96%. Moreover, the fiber reinforced composite material was produced at 150 degreeC using this epoxy resin composition. Table 1 shows the characteristics of the cured resin and the fiber-reinforced composite material obtained from this epoxy resin composition. Both the flexural modulus and the amount of flexure of the cured resin obtained from this epoxy resin composition are greatly improved as compared to Example 3, and the 0 ° compressive strength and Charpy impact value of the fiber reinforced composite material are also shown in Examples. Compared to 3, it was greatly improved.

(Comparative Example 1)
An epoxy resin composition was prepared in the same manner as in Example 1, except that 25 parts of ELM434 was used as the amine type epoxy resin, 25 parts of jER828 and 50 parts of jER1001 were used as the bisphenol type epoxy resin. At this time, the average epoxy equivalent of the bisphenol-type epoxy resin component was 380, and the number of active hydrogen groups was 1.0 equivalent. The obtained epoxy resin composition was cured at 150 ° C. to obtain a cured resin. Moreover, the fiber reinforced composite material was produced at 150 degreeC using this epoxy resin composition. Table 2 shows the properties of the cured resin and fiber-reinforced composite material obtained from this epoxy resin composition. The reaction rate of the cured resin was 100%, but this cured resin had a low glass transition temperature and an insufficient elastic modulus. Further, the fiber reinforced composite material had insufficient glass transition temperature and 0 ° compressive strength.

(Comparative Example 2)
An epoxy resin composition was prepared in the same manner as in Example 1 except that 60 parts of ELM434 was used as the amine type epoxy resin, 20 parts of jER828 and 20 parts of jER1001 were used as the bisphenol type epoxy resin. The average epoxy equivalent of the bisphenol-type epoxy resin component at this time was 332, and the number of active hydrogen groups was 0.7 equivalent. The obtained epoxy resin composition was cured at 150 ° C. to obtain a cured resin. Moreover, the fiber reinforced composite material was produced at 150 degreeC using this epoxy resin composition. Table 2 shows the properties of the cured resin and fiber-reinforced composite material obtained from this epoxy resin composition. The cured resin had a low reaction rate of 88% and an insufficient amount of bending deflection. Further, the fiber reinforced composite material had an insufficient Charpy impact value.

(Comparative Example 3)
An epoxy resin composition was prepared in the same manner as in Example 1 except that diaminodiphenyl sulfone was not blended. The average epoxy equivalent of the bisphenol-type epoxy resin component at this time was 387, and the number of active hydrogen groups was 0.8 equivalent. The obtained epoxy resin composition was cured at 150 ° C. to obtain a cured resin. Moreover, the fiber reinforced composite material was produced at 150 degreeC using this epoxy resin composition. Table 2 shows the properties of the cured resin and fiber-reinforced composite material obtained from this epoxy resin composition. The reaction rate of the cured resin was 97%, but the glass transition temperature was low and the flexural modulus was insufficient. Further, the fiber reinforced composite material had insufficient glass transition temperature and 0 ° compressive strength.

(Comparative Example 4)
An epoxy resin composition was prepared in the same manner as in Example 4 except that 11 parts of Seikacure-S as diaminodiphenylsulfone and 4 parts of DICY7 as dicyandiamide or a derivative thereof were used. At this time, the average epoxy equivalent of the bisphenol-type epoxy resin component was 1433, and the number of active hydrogen groups was 0.9 equivalent. The obtained epoxy resin composition was cured at 150 ° C. to obtain a cured resin. Moreover, the fiber reinforced composite material was produced at 150 degreeC using this epoxy resin composition. Table 2 shows the properties of the cured resin and fiber-reinforced composite material obtained from this epoxy resin composition. The reaction rate of the cured resin was 90%. Further, the glass transition temperature was low and the bending deflection amount was insufficient. Further, the fiber reinforced composite material had insufficient glass transition temperature and Charpy impact value.

(Comparative Example 5)
An epoxy resin composition was prepared in the same manner as in Example 3, except that 28 parts of Seikacure-S was used as diaminodiphenylsulfone and dicyandiamide or a derivative thereof was not used. The average epoxy equivalent of the bisphenol-type epoxy resin component at this time was 332, and the number of active hydrogen groups was 0.8 equivalent. The obtained epoxy resin composition was cured at 150 ° C. to obtain a cured resin. Moreover, the fiber reinforced composite material was produced at 150 degreeC using this epoxy resin composition. Table 2 shows the properties of the cured resin and fiber-reinforced composite material obtained from this epoxy resin composition. The reaction rate of the cured resin was 70%, which was insufficient. Further, the glass transition temperature was low and the bending deflection amount was insufficient. Further, the fiber reinforced composite material had insufficient glass transition temperature and Charpy impact value.

(Comparative Example 6)
An epoxy resin composition was prepared in the same manner as in Example 4 except that the urea compound was not used. At this time, the average epoxy equivalent of the bisphenol type epoxy resin component was 1433, and the number of active hydrogen groups was 0.8 equivalent. The obtained epoxy resin composition was cured at 150 ° C. to obtain a cured resin. Moreover, the fiber reinforced composite material was produced at 150 degreeC using this epoxy resin composition. Table 2 shows the properties of the cured resin and fiber-reinforced composite material obtained from this epoxy resin composition. The reaction rate of the cured resin was 86%, which was insufficient, and the glass transition temperature, bending elastic modulus, and bending deflection were all insufficient. Further, the fiber reinforced composite material had insufficient glass transition temperature, 0 ° compressive strength, and Charpy impact value.

(Comparative Example 7)
An epoxy resin composition was prepared in the same manner as in Comparative Example 1 except that 75 parts of jER828 as a bisphenol type epoxy resin and 6 parts of Vinylec E as a thermoplastic resin were used. The average epoxy equivalent of the bisphenol-type epoxy resin component at this time was 189, and the number of active hydrogen groups was 0.8 equivalent. The obtained epoxy resin composition was cured at 150 ° C. to obtain a cured resin. Moreover, the fiber reinforced composite material was produced at 150 degreeC using this epoxy resin composition. Table 2 shows the properties of the cured resin and fiber-reinforced composite material obtained from this epoxy resin composition. The reaction rate of the cured resin was 100%, but all of the glass transition temperature, bending elastic modulus, and bending deflection were insufficient. Further, the fiber-reinforced composite material was insufficient in both 0 ° compressive strength and Charpy impact value.

(Comparative Example 8)
Prepare an epoxy resin composition in the same manner as in Comparative Example 1 except that 15 parts of jER828 and 60 parts of jER1009 as bisphenol type epoxy resin, 4 parts of DICY7 as dicyandiamide or its derivative were used, and no thermoplastic resin was used. did. At this time, the average epoxy equivalent of the bisphenol-type epoxy resin component was 2678, and the number of active hydrogen groups was 1.0 equivalent. The obtained epoxy resin composition was cured at 150 ° C. to obtain a cured resin. Moreover, the fiber reinforced composite material was produced at 150 degreeC using this epoxy resin composition. Table 2 shows the properties of the cured resin and fiber-reinforced composite material obtained from this epoxy resin composition. The reaction rate of the cured resin was 100%, but the glass transition temperature and bending elastic modulus were insufficient. Further, the fiber reinforced composite material had insufficient glass transition temperature and 0 ° compressive strength.

(Comparative Example 9)
An epoxy resin composition was prepared in the same manner as in Example 7, except that 1 part of DICY7 was used as dicyandiamide or a derivative thereof and 1 part of DCMU99 was used as the urea compound. At this time, the average epoxy equivalent of the bisphenol-type epoxy resin component was 332, and the number of active hydrogen groups was 0.4 equivalent. The obtained epoxy resin composition was cured at 150 ° C. to obtain a cured resin. Moreover, the fiber reinforced composite material was produced at 150 degreeC using this epoxy resin composition. Table 2 shows the properties of the cured resin and fiber-reinforced composite material obtained from this epoxy resin composition. The reaction rate of the cured resin was 85%, which was insufficient, and the glass transition temperature and the amount of bending deflection were also insufficient. Further, the fiber reinforced composite material had insufficient glass transition temperature and Charpy impact value.

  When Example 1 and Example 2 are compared, as a result of using tetraglycidyldiaminodiphenylmethane instead of triglycidyl-p-amino-o-methylphenol as the amine-type epoxy resin, the glass transition temperature of the cured resin and the fiber reinforced composite material It was confirmed that tetraglycidyldiaminodiphenylmethane is more preferable as the amine-type epoxy resin.

  When Example 2 is compared with Example 3, the amount of the amine-type epoxy resin tetraglycidyldiaminodiphenylmethane is increased, and the amount of the bisphenol-type epoxy resin is decreased accordingly. It was confirmed that the glass transition temperature and the flexural modulus of the cured resin were improved by setting the ratio of the blending amount within the more preferable range of the present invention. Moreover, although the Charpy impact value of the fiber reinforced composite material was slightly reduced by such blending, it was confirmed that the 0 ° compressive strength was greatly improved.

  Comparison of Example 3, Example 5, and Example 6 confirmed the effect of the amount of diaminodiphenyl sulfone. That is, the other blending compositions were the same, and the comparison was made with the blending amount of diaminodiphenyl sulfone being 3, 5 and 9 parts. As a result, compared with Example 3 in which 5 parts of diaminodiphenol sulfone was blended in the preferred range of the present invention was blended in Example 3 in which 3 parts were blended and Example 6 in which 9 parts were blended, It was confirmed that the glass transition temperature, the flexural modulus, and the amount of bending deflection were good, and the glass transition temperature, 0 ° compressive strength, and Charpy impact value of the fiber reinforced composite material were also good.

  By comparing Examples 3 and 4, the influence of the average epoxy equivalent of the bisphenol type epoxy resin component was confirmed. It should be noted that the average epoxy equivalent may be regarded as an index corresponding approximately to the average molecular weight when compared within the range of the bisphenol type epoxy resin component. That is, Example 4 in which the average epoxy equivalent of the bisphenol-type epoxy resin component was 1433 within the more preferable range of the present invention was compared with Example 3 in which the average epoxy equivalent was 332, and the glass transition temperature of the cured resin product. However, it was confirmed that both the bending elastic modulus and the bending deflection were improved. In addition, the balance between the 0 ° compressive strength and the Charpy impact value of the fiber reinforced composite material was improved, and as a whole, more favorable characteristics were obtained.

  In Example 7, the amount of the amine type epoxy resin and the bisphenol type epoxy resin, the average epoxy equivalent of the bisphenol type epoxy resin component, and the amount of diaminodiphenol sulfone were more preferably within the range of the present invention. Even when compared with the examples, it was confirmed that the glass transition temperature, the flexural modulus, and the amount of bending deflection of the cured resin were all the best or almost the same as the best. Also, the glass transition temperature, 0 ° compressive strength, and Charpy impact strength of the fiber reinforced composite material are all the best or almost the same as those of the best examples, as with the resin cured product. It was confirmed that.

  In Comparative Examples 1 and 2, the compounding amount of the amine type epoxy resin and the bisphenol type epoxy resin is outside the scope of the present invention. As a result, in Comparative Example 1, the glass transition temperature and the bending elastic modulus were insufficient, and in Comparative Example 2, the reaction rate of the cured product and the amount of bending deflection were insufficient. For this reason, in Comparative Example 1, the glass transition temperature and 0 ° compressive strength of the fiber reinforced composite material were insufficient, and in Comparative Example 2, the Charpy impact value of the fiber reinforced composite material was insufficient.

  In Comparative Example 3, diaminodiphenyl sulfone, which is an essential component of the present invention, is not blended (otherwise the same blending as in Example 1). As a result, the glass transition temperature and bending elastic modulus of the cured product were insufficient. For this reason, the glass transition temperature and 0 ° compressive strength of the fiber reinforced composite material were insufficient.

  In Comparative Example 4, the blending amount of diaminodiphenol sulfone is outside the scope of the present invention (otherwise, the blending is the same as in Example 4). As a result, the glass transition temperature and the flexural modulus of the cured product became insufficient. For this reason, the Charpy impact value of the fiber reinforced composite material became insufficient.

  In Comparative Example 5, the amount of diaminodiphenol sulfone is outside the scope of the present invention, and dicyandiamide or a derivative thereof, which is an essential component of the present invention, is not blended (otherwise, the same as in Example 3) Formulation). As a result, the reaction rate, glass transition temperature, and bending deflection of the cured product were insufficient. For this reason, the glass transition temperature and Charpy impact value of the fiber reinforced composite material were insufficient.

  In Comparative Example 6, the urea compound, which is an essential component of the present invention, is not blended (otherwise the same blending as in Example 4). As a result. The reaction rate, glass transition temperature, bending elastic modulus and bending deflection of the cured product were insufficient. For this reason, the glass transition temperature, 0 ° compressive strength, and Charpy impact value of the fiber-reinforced composite material were insufficient.

  In Comparative Examples 7 and 8, in addition to the compounding amount of the amine type epoxy resin and the bisphenol type epoxy resin being outside the range of the present invention, the average epoxy equivalent of the bisphenol type epoxy resin is outside the preferable range of the present invention. . As a result, compared with Comparative Example 1, in Comparative Example 7, the amount of bending deflection of the cured product was further reduced, so that all of the glass transition temperature, the elastic modulus, and the bending deflection amount became insufficient, and the glass transition of the fiber-reinforced composite material. The temperature, 0 ° compressive strength, and Charpy impact value were all insufficient. In Comparative Example 8, the glass transition temperature and flexural modulus of the cured product were greatly reduced, and the glass transition temperature, 0 ° compressive strength, and Charpy impact value of the fiber reinforced composite material were insufficient.

  Although the comparative example 9 contained all the essential components of this invention within the required range, the reaction rate of hardened | cured material was inadequate and the glass transition temperature and the bending deflection amount were also inadequate. As a result, the glass transition temperature and Charpy impact value of the fiber reinforced composite material were also insufficient.

  According to the present invention, it is possible to provide an epoxy resin composition that provides a cured product having excellent heat resistance, elastic modulus, elongation, etc., and fiber reinforcement that has excellent heat resistance, compressive strength, impact resistance, etc. A composite material can be obtained.

  The epoxy resin composition, prepreg and fiber reinforced composite material according to the present invention can be used for golf club shafts, fishing rods, badminton racket shafts, wheelchair frames, hockey sticks, etc. More preferably, it can be used as a bicycle wheel.

Claims (11)

The following [A] to [F] are included, the reaction rate when cured at 150 ° C. for 1 hour is 90% or more, and the glass transition temperature of the cured product when cured at 150 ° C. for 1 hour is 140 to 170 ° C. And an epoxy resin composition characterized in that the three-point bending deflection specified by the following (I) is 5 mm or more.
[A] Amine type epoxy resin 30 to 55 parts by weight with respect to 100 parts by weight of all epoxy resin components
[B] Bisphenol type epoxy resin 45 to 70 parts by weight with respect to 100 parts by weight of all epoxy resin components [C] Diaminodiphenylsulfone 2 to 9 parts by weight with respect to 100 parts by weight of all epoxy resin components [D] Dicyandiamide or a derivative thereof [E ] Urea compound [F] thermoplastic resin
(I) After defoaming the uncured epoxy resin composition in a vacuum, in a mold set to a thickness of 2 mm with a 2 mm thick “Teflon (registered trademark)” spacer, at 150 ° C. for 1 hour Cured to obtain a cured resin having a thickness of 2 mm. A test piece having a width of 10 mm and a length of 60 mm was cut out from the cured resin, and the length between spans was measured using an Instron universal testing machine (Instron). Is set to 32 mm, the crosshead speed is set to 2.5 mm / min, and three-point bending is performed according to JIS K7171 (1994), and the average value of the bending deflection amount at n = 5 is defined as the three-point bending deflection amount. 2. The epoxy according to claim 1, wherein the total amount of active hydrogen groups of the [C] component and the [D] component is in the range of 0.6 to 1.0 equivalent to 1 equivalent of epoxy groups of all epoxy resin components. Resin composition. The epoxy resin composition of Claim 1 or 2 which contains 1-3 weight part of said [E] with respect to 100 weight part of all the epoxy resin components. The epoxy resin composition according to any one of claims 1 to 3, wherein the epoxy resin composition has a three-point bending elastic modulus specified by the following (II) of 3.5 GPa or more.
(II) After defoaming the uncured epoxy resin composition in a vacuum, in a mold set to a thickness of 2 mm with a 2 mm thick “Teflon (registered trademark)” spacer, at 150 ° C. for 1 hour Cured to obtain a cured resin having a thickness of 2 mm. A test piece having a width of 10 mm and a length of 60 mm was cut out from the cured resin, and the length between spans was measured using an Instron universal testing machine (Instron). Is set to 32 mm, the crosshead speed is set to 2.5 mm / min, and three-point bending is performed according to JIS K7171 (1994), and an average value of bending elastic modulus at n = 5 is defined as three-point bending elastic modulus. A prepreg obtained by impregnating a fiber base material with the epoxy resin composition according to claim 1. A fiber-reinforced composite material obtained by curing the prepreg according to claim 5. The manufacturing method of the fiber reinforced composite material which hardens the prepreg of Claim 5 on 150-170 degreeC on the hardening conditions within 1 hour. Fibers obtained by curing a prepreg comprising a fiber base material impregnated with an epoxy resin composition containing the following [A] to [F] and having a reaction rate of 90% or more when cured at 150 ° C. for 1 hour. A fiber reinforced composite material, wherein the fiber reinforced composite material constitutes a bicycle part.
[A] Amine type epoxy resin 30 to 55 parts by weight with respect to 100 parts by weight of all epoxy resin components
[B] Bisphenol type epoxy resin 45 to 70 parts by weight with respect to 100 parts by weight of all epoxy resin components [C] Diaminodiphenylsulfone 2 to 9 parts by weight with respect to 100 parts by weight of all epoxy resin components [D] Dicyandiamide or a derivative thereof [E ] Urea compound [F] thermoplastic resin The fiber-reinforced composite material according to claim 8, wherein the bicycle component is a bicycle wheel. When the epoxy resin composition is cured at 150 ° C. for 1 hour, the glass transition temperature of the cured product is 140 to 170 ° C., and the three-point bending deflection specified by (I) below is 5 mm or more. The fiber-reinforced composite material according to claim 8 or 9, wherein
(I) After defoaming the uncured epoxy resin composition in a vacuum, in a mold set to a thickness of 2 mm with a 2 mm thick “Teflon (registered trademark)” spacer, at 150 ° C. for 1 hour Cured to obtain a cured resin having a thickness of 2 mm. A test piece having a width of 10 mm and a length of 60 mm was cut out from the cured resin, and the length between spans was measured using an Instron universal testing machine (Instron). Is set to 32 mm, the crosshead speed is set to 2.5 mm / min, and three-point bending is performed according to JIS K7171 (1994), and the average value of the bending deflection amount at n = 5 is defined as the three-point bending deflection amount. The fiber-reinforced composite material according to any one of claims 8 to 10, wherein the epoxy resin composition has a three-point bending elastic modulus specified by the following (II) of 3.5 GPa or more.
(II) After defoaming the uncured epoxy resin composition in a vacuum, in a mold set to a thickness of 2 mm with a 2 mm thick “Teflon (registered trademark)” spacer, at 150 ° C. for 1 hour Cured to obtain a cured resin having a thickness of 2 mm. A test piece having a width of 10 mm and a length of 60 mm was cut out from the cured resin, and the length between spans was measured using an Instron universal testing machine (Instron). Is set to 32 mm, the crosshead speed is set to 2.5 mm / min, and three-point bending is performed according to JIS K7171 (1994), and an average value of bending elastic modulus at n = 5 is defined as three-point bending elastic modulus.