JPH1143547A - Production of prepreg - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a prepreg excellent in surface smoothness, handleability and resin flow, when molded, by heating a matrix resin composition comprising a thermosetting resin composition, a radically polymerizable compound and a polymerization initiator in a process for immersing reinforcing fibers in the matrix resin composition, thus allowing the polymerization reaction of the radically polymerizable unsaturated compound to proceed at the same time as the immersion. SOLUTION: This prepreg is obtained by heating a resin composition comprising 100 pts.wt. of a thermosetting resin composition (preferably a composition comprising an epoxy resin and a curing agent), 1-20 pts.wt. of a radically polymerizable unsaturated compound (e.g. triethylene glycol diacrylate), and a thermally radical-generating polymerization initiator (e.g. 2,2' azobisisobutyronitrille) at a temperature (e.g. 40-140 deg.C) substantially not causing the reaction of the thermosetting resin in the composition in the process for immersing the reinforcing fibers (preferably carbon fibers, etc.,).

Description

DETAILED DESCRIPTION OF THE INVENTION

The present invention comprises a reinforcing material such as glass fiber, carbon fiber, aramid fiber and boron fiber and a thermosetting resin, which are used for structural materials such as aircraft, vehicles, ships and buildings, and sports equipment. The present invention relates to a prepreg used for producing a fiber-reinforced composite material and a method for producing the same.

[0002]

2. Description of the Related Art Fiber-reinforced composite materials comprising a reinforcing fiber and a matrix resin are lightweight and have excellent mechanical properties. Therefore, structural materials for aircraft, vehicles, ships, buildings, etc., golf shafts, fishing rods, tennis rackets, etc. Widely used for sports equipment.

[0003] Various methods are used for the production of fiber-reinforced composite materials, and a method using a prepreg, which is a sheet-like, tape-like, or string-like intermediate substrate in which a matrix resin is impregnated with reinforcing fibers, is widely used. Used. In this method, after laminating a plurality of prepregs, a molded product is obtained by heating.

[0004] As the matrix resin used for the prepreg, both thermosetting resins and thermoplastic resins are used. In most cases, thermosetting resins are used. In this case, a prepreg obtained by impregnating an uncured thermosetting resin with a reinforcing fiber is used as a prepreg, and after laminating, a fiber-reinforced composite material is manufactured.

[0005] In order to increase the specific strength and the specific elastic modulus of the fiber-reinforced composite material, it is necessary to increase the volume content of the reinforcing fibers. Therefore, in fields where high performance is required, prepregs that use long fibers, which are advantageous to increase the volume content, as reinforcing fibers, especially reinforced long fibers, which can maximize the volume content, in one direction Prepreg used as a fiber is preferably used.

[0006] In the field of sporting goods such as fishing rods and golf shafts, demand for prepregs having a particularly high volume content of reinforcing fibers and prepregs having a small thickness has been increasing in order to reduce the weight.

In general, in the production of prepreg, there are many advantages that the viscosity of the matrix resin is lower. In particular, when producing a prepreg having a high volume content of reinforcing fibers or a thin sheet-shaped prepreg, it is desirable that the viscosity of the uncured matrix resin is as low as possible. For example, when a sheet-shaped prepreg is produced, as a method of impregnating a matrix resin into a reinforcing fiber, two types of release paper coated with a matrix resin or two types of release paper coated with a matrix resin and a release paper not coated are used. Is generally sandwiched from above and below, but in this case, if the viscosity of the matrix resin is high, various problems occur.

First, when the viscosity of the matrix resin is high, it is difficult to sufficiently impregnate the inside of the reinforcing fiber bundle with the matrix resin. Therefore, when using a matrix resin with high viscosity, it is necessary to raise the temperature and lower the resin viscosity in order to perform sufficient impregnation,
When a heat history of a certain degree or more is added to the thermosetting resin, the curing reaction of the resin composition proceeds, or the curing agent in the resin composition dissolves or deteriorates, thereby causing a problem of shortening the pot life of the prepreg. . This is a serious problem particularly when a matrix resin having a low curing temperature is used. If the viscosity of the matrix resin is sufficiently low, such problems are unlikely to occur because the impregnation of the reinforcing fibers becomes easy, the speed of the production line can be increased, and the productivity can be improved.

Second, if the viscosity of the matrix resin is high, the strands of the reinforcing fibers are less likely to spread during impregnation, resulting in insufficient surface smoothness. In particular, such a problem often occurs when a thin prepreg is manufactured. Then, in order to expand the strand in a state where the resin viscosity is relatively high and sufficiently impregnate the matrix resin, it is necessary to perform impregnation by increasing the external pressure such as roller pressure, but when the fiber is pressed with a high pressure, Especially in the case of a twisted reinforcing fiber such as false twist, the fiber bundle is once expanded by pressure, but if the obtained prepreg is left unattended, the fiber bundle returns to its original state over time. A phenomenon of so-called springback is likely to occur. When springback occurs, the amount of resin on the prepreg surface decreases, and the tackiness (adhesion) of the prepreg decreases over time.

[0010] Further, in the case of producing not only a thin prepreg but also a sheet-like prepreg, if the viscosity of the matrix resin is low, the strand is likely to spread during impregnation, so that a fiber bundle having a large number of single fibers can be used. In that case, in general, reinforcing fibers having a large number of single fibers constituting a fiber bundle are economically advantageous because they can be obtained at a low cost, and also have a low productivity because the number of strands required is small. Also improve.

Further, when the viscosity of the matrix resin is sufficiently low, a method in which a release paper is not necessarily required, for example, a method in which a reinforcing fiber is passed through an immersion layer filled with a resin composition, or a method in which a reinforcing fiber is passed at a constant speed Thus, a prepreg can be manufactured without difficulty even by a method of passing through a die to which a matrix resin is supplied. Using such a method is not only economically advantageous because it does not require release paper, which is mostly only waste, but it also makes it possible to produce with the method using release paper. It is also possible to manufacture extremely thick prepregs, which are difficult to manufacture, without difficulty.

However, when the viscosity of the matrix resin in the produced prepreg is low, various problems occur. First
Is a resin flow at the time of molding. When a fiber reinforced composite material is manufactured using a prepreg, a method of laminating the prepregs and then heating and pressurizing to cure the matrix resin is used. At this time, a phenomenon in which the resin whose viscosity has decreased due to heating flows out due to pressure, and a resin flow occurs. When the viscosity of the matrix resin is low, the resin flow increases. There is no problem if the resin flow is sufficiently small, but if the resin flow is too large, the weight variation of the molded product occurs, the resin lacks a portion in the molded product, or the voids in the molded product increase, which is preferable. Absent.

[0013] The second is the handling of the prepreg. If the matrix resin of the prepreg has too low viscosity, stickiness on the surface is large and handling becomes difficult. For example, the resin adheres to a worker's hand or a workbench that has touched the prepreg. Further, when the matrix resin has a low viscosity, when the laminated prepreg is peeled off for repair, the resin is peeled off like a string, and the repair work becomes difficult.

Further, when laminating prepregs, appropriate tackiness (adhesion) is required between the stacked prepregs, but if the viscosity of the matrix resin is low, tackiness is insufficient. If the tackiness is insufficient, the stacked prepregs will easily come off. This is a problem particularly when lamination is performed by winding a prepreg around a mandrel having a small radius of curvature as in the manufacture of a fishing rod or a golf shaft. In order for the resin to have no tackiness and to have an appropriate tackiness, the matrix resin needs to have a certain level of high viscosity. Furthermore, if the viscosity of the matrix resin is low, the resin on the prepreg surface will easily sink into the fiber bundle,
There is also a problem that the adhesiveness of the prepreg decreases over time.

When a manufacturing method is used in which prepregs are laminated while unwinding the prepregs from a tape-shaped or string-shaped prepreg wound on a bobbin, unwinding of the prepregs becomes a problem. When the viscosity of the matrix resin decreases, the wound prepregs adhere to each other, and the unwinding property deteriorates.

In the production of prepreg, the matrix resin viscosity is set to an appropriate value in consideration of the above trade-off. However, there is often no resin viscosity range that satisfies all the required conditions, and some performance is sacrificed. There are quite a few cases where it is inevitable or impossible to manufacture. For example, such a problem often occurs when the volume content of the reinforcing fibers of the prepreg is large, when the curing temperature of the matrix resin is low, or when the requirements for the resin flow are severe.

In order to solve the above-mentioned trade-off that exists with respect to the viscosity of the matrix resin, there is a method of impregnating with a low-viscosity matrix resin composition and then increasing the viscosity of the matrix resin by some treatment. Some methods that can be applied for that purpose have been proposed.

In JP-A-52-100574 and JP-A-9-3158, a reinforcing resin is impregnated with a matrix resin containing an epoxy resin and a photopolymerizable compound, and then photopolymerized by light irradiation. A method for increasing the viscosity of a matrix resin is disclosed. Usually, ultraviolet light is used for photopolymerization. This method is effective when the reinforcing fibers transmit ultraviolet light well, such as glass fiber.However, when using reinforcing fibers that do not transmit ultraviolet light, such as carbon fiber, aramid fiber, and boron fiber, the prepreg is used. It is not effective because no internal thickening reaction occurs.

JP-A-58-19332 discloses a method of impregnating a reinforcing fiber with a matrix resin containing an epoxy resin and an acrylate monomer and then polymerizing the acrylate monomer by electron beam irradiation to increase the viscosity of the matrix resin. Have been. This method does not depend on the transparency of the reinforcing fiber, but when applied to a thick prepreg, it is necessary to increase the acceleration voltage. An electron beam irradiator having a high accelerating voltage is large-scale because it shields harmful X-rays generated by electron beam irradiation, and is difficult to incorporate into an ordinary production line.

In JP-A-3-103446, after reinforcing resin is impregnated with a resin composition containing an epoxy resin, a vinyl compound and a vinyl compound having an epoxy group,
A method is disclosed in which either a curing reaction of an epoxy resin or a radical polymerization reaction of a vinyl compound is preliminarily reacted by heat treatment or light irradiation to form a B-stage (increase the viscosity). When the viscosity is increased by heat treatment among these, there is no difficulty seen in the method using light or radiation as described above, but in the publication, as a specific manufacturing method, a resin composition is impregnated into a reinforcing fiber. It is disclosed that after aging at room temperature or higher, it is treated at a high temperature to form a B-stage. In such a method, there is a problem that productivity is impaired because extra steps of aging and B-stage are added as compared with a normal prepreg manufacturing process.

Further, in such a method of aging or B-stage, it is difficult to separate the reaction of the epoxy resin from the reaction of the vinyl compound, and there is a problem that the pot life of the prepreg is shortened. No mention is made of the separation between the reaction of the epoxy resin and the reaction of the vinyl compound.

Further, in the example described in the publication, the reinforcing fibers are impregnated with the matrix resin in a tensionless state.
If the heat treatment is performed for a long period of time, the viscosity of the resin temporarily decreases, so that the resin flows and the fiber is bent, and thus the quality of the prepreg tends to deteriorate.

[0023]

SUMMARY OF THE INVENTION In view of the background of the prior art, the present invention solves the trade-off between the viscosity of a matrix resin, which is required to have a low viscosity during impregnation and a high viscosity during prepreg. Further, it is an object of the present invention to provide a method for producing a prepreg which can be realized without requiring significant modification of a conventional production facility.

[0024]

The present invention employs the following means in order to solve the above-mentioned problems. That is, the method for producing a prepreg of the present invention comprises a resin composition comprising a thermosetting resin composition (A1), a radically polymerizable unsaturated compound (A2), and a polymerization initiator (A3) that generates a radical by heating as essential components. Object A, reinforcing fiber B
In the step of impregnating (A), the resin composition A is heated to advance the polymerization reaction of the A2 component.

[0025]

DETAILED DESCRIPTION OF THE INVENTION The present invention has been made to solve the above-mentioned problems, that is, the need for a large viscosity of a matrix resin, which requires a low viscosity at the time of impregnation and a high viscosity at the time of prepreg, without requiring a major modification of the conventional production equipment. As a result of intensive studies on a method for solving the trade-off, as the resin composition A, A1: a thermosetting resin composition A2: a radically polymerizable unsaturated compound A3: a polymerization initiator which generates a radical by heating as an essential component When the resin composition A is impregnated into the reinforcing fibers, the resin composition has a low viscosity, and the radicals released from the A3 component by heating during the impregnation cause the A2 component to polymerize to a high molecular weight. As a result, the resin composition A is thickened, and thus the prepreg finally obtained is excellent in handleability and resin flow during molding. To solve the problem at once.

The thermosetting resin composition (A1), which is an essential component of the resin composition A of the present invention, has substantially no radical polymerizability, that is, a curing reaction is performed only by an ionic mechanism. A mixture of a prepolymer or a composition in which a curing agent or a curing catalyst is blended is preferably used. Specifically, epoxy resin composition, isocyanate resin composition, phenol resin composition, xylene resin composition, furan resin composition, melamine resin composition, benzoguanamine resin composition, urea resin composition, silicone resin composition, etc. Can be used. Among them, an epoxy resin composition having excellent heat resistance and elastic modulus is particularly preferably used for fiber-reinforced composite materials.

As such an epoxy resin composition, a mixture of an epoxy resin which is a prepolymer having an epoxy group in a molecule and a curing agent is used.

As the epoxy resin, a compound having a plurality of epoxy groups in a molecule is used. For example,
Bisphenol A type epoxy resin, bisphenol F type epoxy resin, naphthalene type epoxy resin, novolak type epoxy resin, glycidylamine type epoxy resin such as tetraglycidyldiaminodiphenylmethane, triglycidylaminophenol, tetraglycidylxylenediamine, tetrakis (glycidyloxy) A glycidyl ether type epoxy resin such as phenyl) ethane or tris (glycidyloxy) methane, or a combination thereof is preferably used.

As such a bisphenol type epoxy resin, for example, as a bisphenol A type, "Epicoat" 828, "Epicoat" 1001, "Epicoat" 1004 (manufactured by Yuka Shell Epoxy Co., Ltd.) or "Epototo" YD128 (Toto Tokyo) "Epiclon" 840, "Epiclon" 850, "Epiclon" 855, "Epiclon" 860, "Epiclon" 1
050 (manufactured by Dainippon Ink and Chemicals, Inc.), ELA1
28 (manufactured by Sumitomo Chemical Co., Ltd.) and DER331 (manufactured by Dow Chemical Company) can be used. Further, as a bisphenol F type, “Epiclon” 830
(Dai Nippon Ink Chemical Industry Co., Ltd.), "Epicoat"
807 (manufactured by Yuka Shell Epoxy Co., Ltd.). Examples of the phenol novolak type epoxy resin include “Epicoat” 152, “Epicoat” 154 (manufactured by Yuka Shell Epoxy), DER485 (manufactured by Dow Chemical Company), and EPN1138 and 1139 (manufactured by Ciba Geigy).
And those marketed under the trade name such as

Examples of the curing agent include aromatic amines such as diaminodiphenylmethane and diaminodiphenylsulfone, aliphatic amines, imidazole derivatives, dicyandiamide, tetramethylguanidine, thiourea-added amines, and the like.
It is possible to use a carboxylic anhydride such as methylhexahydrophthalic anhydride, a carboxylic acid hydrazide, a carboxylic acid amide, a polyphenol compound such as a novolak resin, a polymercaptan, or a Lewis acid complex such as a boron trifluoride ethylamine complex. it can.

These curing agents may be combined with an appropriate curing aid to enhance the curing activity. As a preferred example, 3- (3,4-dichlorophenyl) -1,1-dimethylurea (DCMU) is added to dicyandiamide.
Can be used as a curing aid, and examples of combining a carboxylic acid anhydride or a novolak resin with a tertiary amine as a curing aid can be used. Most curing aids are
As in the examples given here, the epoxy resin alone has the ability to cure the epoxy resin, and in fact, often acts as a curing agent at the same time.

These hardeners and hardeners used in the present invention are used for realizing stability in the step of impregnating the resin composition A into the reinforcing fibers B (step 1) and for preserving the obtained prepreg sufficiently. It is preferable to have a heat-activated type potential in order to provide stability.

The term "thermally active type latent" as used herein means a state in which the activity is low as it is, but after a certain heat history, causes a phase change or a chemical change to change to a state in which the activity is high. Means nature. In the following description, the term “latent” refers to the latent of the heat activated type.

When a curing aid is not used, it is preferable that the curing agent has a potential. When using a curing aid,
It is preferred that at least the curing aid has a potential.
As a curing agent to be used together with the latent curing aid, a curing agent having a potential is naturally preferably used. However, as long as the reactivity alone is low, the curing agent has no particular potential (that is, the latent curing agent has a low thermal history. Curing agents which do not cause a change or a chemical change) are also preferably used.

As one method for imparting potential, a method in which a particulate hardener or hardener is dispersed in an epoxy resin without being dissolved is preferably used. After passing through a certain heat history, these are dissolved in the epoxy resin to form a uniform phase, and the state becomes high.

As a particulate latent curing agent, dicyandiamide is preferably used, but since it alone has a high curing temperature, it is particularly preferred to use this in combination with a particulate latent curing aid. As a particulate curing aid that can be suitably combined with dicyandiamide, a urea derivative substituted with an aryl group is preferably used. In particular, a urea derivative substituted at the 1-position with an aryl group and substituted at a 3-position with two alkyl groups is preferred. Urea derivatives are preferably used. Specific examples of the urea derivative preferably substituted with an aryl group include 1- (3,4-dichlorophenyl) -3,3-dimethylurea, 1- (4-chlorophenyl) -3,3-dimethylurea, 1-dimethyl-3-
Phenylurea, 1- (3,4-dimethylphenyl)-
3,3-dimethylurea, 1- (3,4-dimethylphenyl) -3,3-dimethylurea, 1- (2-hydroxyphenyl) -3,3-dimethylurea, 2,4-bis (N,
(N-dimethylureido) -toluene can be used.

Examples of the particulate latent curing agent include solid imidazole derivatives such as 2-methylimidazole, 2-phenylimidazole and 2-phenyl-4-methylimidazole.
Methyl imidazole, 1- (2-cyanoethyl) -2-
Phenylimidazole or the like, a glycidyl compound added to an imidazole derivative, or a salt of an imidazole derivative with an organic acid such as trimellitic acid or isocyanuric acid can also be used.

Further, these imidazole derivatives can be suitably used in combination with dicyandiamide as a curing agent as a latent curing aid.

As the particulate latent curing agent, solid organic acid hydrazides can be preferably used. Examples of preferably used solid organic acid hydrazides include adipic acid dihydrazide, 2,6-naphthalenedicarboxylic acid dihydrazide, isophthalic acid dihydrazide,
1,3-bis (hydrazinocarboethyl) -5-isopropylhydantoin, 7,11-octadecadien-
1,18-dicarbohydrazide, eicosane diacid dihydrazide and the like can be used.

As the particulate latent curing agent, solid aromatic polyamines can be preferably used. Solid aromatic polyamines preferably used are 3,
3′-diaminodiphenyl sulfone, 4,4′-diaminodiphenyl sulfone and the like can be used.

In addition, those obtained by mixing a curing agent or a curing assistant with a resin to form particles, those coated with another substance to form microcapsules, and those adsorbed on inorganic particles such as viscous minerals, It can be suitably used as a hardening agent or a curing assistant.

As the heat-active latent curing agent or curing aid, a type that generates an active component by a chemical reaction due to heat can be used. In this case, it may be dissolved in an epoxy resin. Examples of such types of latent curing agents and curing assistants include imidazole and transition metal complexes and amine imides.

When a latent curing assistant and a curing agent having low reactivity alone are combined, the curing agent may be particles or may be uniformly dissolved in an epoxy resin. Examples of such combinations include acid anhydrides, polyphenols, and polymercaptans as curing agents, and 3 as curing aids.
Salts of secondary amines, such as tris (dimethylaminomethyl)
A case where phenol tris-ethylhexylate is used is exemplified.

In the present invention, the radical polymerizable unsaturated compound (A2) is a low molecular weight compound or a high molecular weight compound containing a radical polymerizable unsaturated bond, that is, a double bond or a triple bond in a molecule.

As the component A2, a single compound may be used, or a mixture of plural kinds of compounds may be used. When a single compound is used, a compound having a plurality of radically polymerizable unsaturated bonds in the molecule is used. When a mixture of a plurality of compounds is used, one radically polymerizable unsaturated bond is used in the molecule. And a compound having a plurality of radically polymerizable unsaturated bonds in the molecule, and a compound having a plurality of radically polymerizable unsaturated bonds in the molecule.
It is preferable to mix the two components at 50% by weight or more in order to make the high molecular weight component generated by radical polymerization have a crosslinked structure and obtain a large viscosity increasing effect.

Preferred examples of the low molecular weight compound having one radically polymerizable unsaturated bond in the molecule include the following. Phenoxyethyl acrylate (for example, "Biscoat" manufactured by Osaka Organic Chemical Industry Co., Ltd.)
# 192), ethoxydiethylene glycol acrylate (for example, "Light Acrylate" EC manufactured by Kyoeisha Chemical Co., Ltd.)
-A), methoxytriethylene glycol acrylate (for example, “Light Acrylate” MTG manufactured by Kyoeisha Chemical Co., Ltd.)
-A), methoxydipropylene glycol acrylate (for example, “Light Acrylate” DPM manufactured by Kyoeisha Chemical Co., Ltd.)
-A), isobornyl acrylate (for example, “Light Acrylate” IB-XA manufactured by Kyoeisha Chemical Co., Ltd.), phenylglycidyl ether acrylic acid adduct (for example, “Denacol Acrylate” DA-141 manufactured by Nagase Kasei Kogyo Co., Ltd.) or the like is used. Can be.

Preferred examples of the low molecular weight compound having a plurality of radically polymerizable unsaturated bonds in the molecule include a low molecular weight compound having two radically polymerizable unsaturated bonds.
Triethylene glycol diacrylate (eg, “Light Ester” 3EG-A manufactured by Kyoeisha Chemical Co., Ltd.), tetraethylene glycol diacrylate (eg, “Aronix” M-240 manufactured by Toa Gosei Chemical Industry Co., Ltd.), neopentyl glycol diacrylate (eg, Kyoeisha Chemical Co., Ltd.) "Light Ester" NP-A (manufactured by Kyoeisha Chemical Co., Ltd.), 1,6-hexanediol diacrylate (for example, "Light Ester" 1,6HX-A manufactured by Kyoeisha Chemical Co., Ltd.), and diacrylate of bisphenol A propylene oxide adduct (for example, manufactured by Kyoeisha Chemical Co., Ltd.) "Light ester" BP-2PA), bisphenol A
Ethylene oxide adduct diacrylate (for example, "Neomer" BA-641 manufactured by Sanyo Kasei Co., Ltd.), hydrogenated bisphenol A propylene oxide adduct diacrylate (for example, "Neomer" HA-605 manufactured by Sanyo Chemical Co., Ltd.), hydrogenated bisphenol A ethylene oxide adduct Diacrylate (for example, “Neomer” HA-601 manufactured by Sanyo Kasei Co., Ltd.) and diacrylate of bisphenol S ethylene oxide adduct (for example, “Aronix” M-2 manufactured by Toagosei Chemical Industry Co., Ltd.)
05), dimethylolpropane tricyclodecane diacrylate (for example, “Light Ester” D manufactured by Kyoeisha Chemical Co., Ltd.)
CP-A), ethylene glycol dimethacrylate (eg, “Light Ester” EG, manufactured by Kyoeisha Chemical Co., Ltd.), diethylene glycol dimethacrylate (eg, “Light Ester” 2EG, manufactured by Kyoeisha Chemical Co., Ltd.), triethylene glycol dimethacrylate (eg, “manufactured by Sanyo Chemical Co., Ltd.”) Neomer ”
PM-201), 1,4-butanediol dimethacrylate (for example, "Light Ester" 1.4 manufactured by Kyoeisha Chemical Co., Ltd.)
BG), 1,6-hexanediol dimethacrylate (for example, "Light Ester" 1.6H manufactured by Kyoeisha Chemical Co., Ltd.)
X), glycerin dimethacrylate (eg, “Light Ester” G-101P manufactured by Kyoeisha Chemical Co., Ltd.), bisphenol A ethylene oxide adduct dimethacrylate (eg, “Light Ester” BP-2EM manufactured by Kyoeisha Chemical Co., Ltd.), bisphenol A propylene oxide adduct Methacrylate, bis (2-acryloyloxyethyl) (2-hydroxyethyl) cyanurate (eg, “Aronix” M-215 manufactured by Toagosei Chemical Industry Co., Ltd.), bisphenol A diglycidyl ether acrylic acid adduct (eg, “Epoxy” manufactured by Kyoeisha Chemical Co., Ltd.) Ester “3000A), bisphenol A ethylene oxide adduct diglycidyl ether acrylic acid adduct, bisphenol A ethylene oxide adduct diglycidyl ether methacrylic acid adduct, bisphenol A Propylene oxide adduct diglycidyl ether acrylic acid adduct (e.g. Kyoeisha Chemical Co., Ltd. "epoxy ester" 3002A), a bisphenol A propylene oxide adduct diglycidyl ether methacrylic acid adduct (e.g. Kyoeisha Chemical Co., Ltd. "epoxy ester"
3002M), glycerol diglycidyl ether acrylic acid adduct (eg, “Epoxyester” 80MFA manufactured by Kyoeisha Chemical Co., Ltd.), diglycidyl phthalate acrylic acid adduct (eg, “Denacol Acrylate” DA-721 manufactured by Nagase Kasei Kogyo Co., Ltd.), diglycidyl Tetrahydrophthalate acrylic acid adduct (eg, “Denacol Acrylate” DA-722 manufactured by Nagase Kasei Kogyo Co., Ltd.), resorcinol diglycidyl ether methacrylic acid adduct (eg, “Denacol Acrylate” DA manufactured by Nagase Kasei Kogyo Co., Ltd.)
-201), diallyl phthalate, diallyl isophthalate, diallyl terephthalate, and the like, as low molecular weight compounds having three radical polymerizable unsaturated bonds, trimethylolpropane triacrylate (for example, "Aronix" M-309 manufactured by Toa Gosei Chemical Industry Co., Ltd.) Pentaerythritol triacrylate (for example, "Aronix" M-305 manufactured by Toa Gosei Chemical Industry Co., Ltd.), trimethylolpropane trimethacrylate (for example, "Light Ester" TMP manufactured by Kyoeisha Chemical Co., Ltd.), tris (2-acryloyloxyethyl) cyanurate (for example, "Aronix" M-315 manufactured by Toa Gosei Chemical Industry Co., Ltd., tris (2-acryloyloxyethyl) phosphate (for example, "Biscoat" 3PA manufactured by Osaka Organic Chemical Industry Co., Ltd.), glycerol triglycidyl ether Acrylic acid adduct (e.g. Nagase Kasei Kogyo Co., Ltd. "Denacol acrylate" DA-314),
Examples of low molecular weight compounds having three radical polymerizable unsaturated bonds such as triallyl cyanurate include pentaerythritol tetraacrylate (eg, “Light Ester” BP-4A manufactured by Kyoeisha Chemical Co., Ltd.) and glycerin dimethacrylate isophorone diisocyanate adduct (eg, Kyoeisha) Urethane acrylate UA-101I manufactured by Chemical Co., Ltd., glycerin dimethacrylate hexamethylene diisocyanate adduct (for example, urethane acrylate UA-101H manufactured by Kyoeisha Chemical Co., Ltd.), glycerin dimethacrylate tolylene diisocyanate adduct (for example, urethane acrylate UA-101T manufactured by Kyoeisha Chemical Co., Ltd.) ) Such as dipentaerythritol pentaacrylate (for example, "Neomer" manufactured by Sanyo Chemical Industries, Ltd.) as a low molecular compound having five radical polymerizable unsaturated bonds. DA-600), dipentaerythritol hexaacrylate (for example, "Light Ester" DPE-6A manufactured by Kyoeisha Chemical Co., Ltd.), pentaerythritol trimethacrylate isophorone diisocyanate adduct (for example, low molecular weight compounds having six radical polymerizable unsaturated bonds). For example, urethane acrylate UA-306I manufactured by Kyoeisha Chemical Co., Ltd., pentaerythritol trimethacrylate hexamethylene diisocyanate adduct (eg, urethane acrylate UA-306 manufactured by Kyoeisha Chemical Co., Ltd.)
H), pentaerythritol trimethacrylate tolylene diisocyanate adduct (for example, urethane acrylate UA-306T manufactured by Kyoeisha Chemical Co., Ltd.) and the like can be used.

Further, a polymer or an oligomer having a radical polymerizable unsaturated bond at the terminal, side chain or main chain can also be used. For example, those obtained by esterifying terminal hydroxyl groups of polyethylene glycol or polypropylene glycol with an acrylate or methacrylic acid, aliphatic diols such as ethylene glycol, dibasic acids such as adipic acid, and disocyanates such as tolylene diisocyanate. The polyester oligomer containing urethane group, obtained by reacting the above, is obtained by esterifying a terminal hydroxyl group of a urethane group-containing polyester oligomer with acrylic acid or methacrylic acid, polyester containing maleic acid or fumaric acid as an acid component, nadic anhydride or ethynyl phthalic anhydride, etc. For example, polyimide having an amino terminal blocked with an acid anhydride having a radical polymerizable unsaturated bond can be used.

Further, together with radically polymerizable unsaturated bonds, epoxy groups, carboxyl groups, hydroxyl groups, alkoxymethyl groups, primary or secondary amines, amides, 1,2-
A low-molecular or high-molecular compound having a partial structure capable of reacting with the A1 component such as a dicarboxylic anhydride structure or a nitrogen-containing heterocycle can also be used.

Examples of such a compound having one radical polymerizable unsaturated bond include 2-acryloyloxyethyl hydrogen phthalate (for example, "Biscoat"# 2000, manufactured by Osaka Organic Chemical Industry Co., Ltd.) and 2-acryloyloxypropyl Hydrogen phthalate (eg, “Biscoat” # 2100 manufactured by Osaka Organic Chemical Industry Co., Ltd.), 2-methacryloyloxyethyl hydrogen phthalate (eg, “Light Ester” HO-MP manufactured by Kyoeisha Chemical Co., Ltd.), 4-hydroxybutyl acrylate, 2-acryloyloxyethyl 2-Hydroxypropyl phthalate (for example, "Biscoat"# 2311HP manufactured by Osaka Organic Chemical Industry Co., Ltd.), maleic anhydride, nadic anhydride, and the like can be used, and bisphenol A jig having two radically polymerizable unsaturated bonds can be used. Ether acrylate moiety adduct (e.g. Highpolymer Co. "Ripoxy" SP-1509
H1), bis (2-acryloyloxyethyl) 2-hydroxyethyl cyanurate (for example, “Aronix” M-215 manufactured by Toa Gosei Chemical Industry Co., Ltd.) and the like can be used. The compounding of these components forms a chemical bond between the polymer of the A2 component and the A1 component in the final cured product of the resin composition A, and has the effect of improving morphology and physical properties.

The component A2 is blended so as to be suitable for the effect of increasing the viscosity required in a target process. Usually, the compounding amount of the component A2 is 1 to 20 parts by weight based on 100 parts by weight of the component A1. It is good to do.

In the present invention, an azo compound, an organic peroxide or the like can be used as the polymerization initiator (A3) which generates a radical by heating. As the azo compound, 2,2′-azobisisobutyronitrile, 1,1 ′
-Azobis (cyclohexane-1-carbonitrile) and the like can be used.

As the organic peroxide, 1,1-bis (t
-Butylperoxy) -2,2,5-trimethylcyclohexane (for example, "Perhexa" 3M-9 manufactured by NOF Corporation)
5), 1,1-bis (t-butylperoxy) cyclododecane (for example, "Perhexa" CD manufactured by NOF Corporation),
1,1,3,3-tetramethylhydroperoxide (for example, "Perocta" H manufactured by NOF Corporation), 1,1-dimethylbutyl peroxide (for example, "Perhexyl" H manufactured by NOF Corporation), bis (1-t-butyl) Peroxy-1-methylethyl) benzene (for example, "Perbutyl" P manufactured by NOF Corporation), dicumyl peroxide (for example, "Parkmill" D manufactured by NOF Corporation), 2,5-dimethyl-2,5-bis (t-butyl) Peroxy) hexane (eg, “Perhexa” 25B manufactured by NOF Corporation), t-butylcumyl peroxide (eg, “Perbutyl” C manufactured by NOF Corporation), di-t
-Butyl peroxide (eg, “Perbutyl” D manufactured by NOF Corporation), 2,5-dimethyl-2,5-bis (t-butylperoxy) hexine (eg, “Perhexyl” 25B manufactured by NOF Corporation), benzoyl peroxide, Lauroyl oxide (eg, “Perloyl” L manufactured by NOF Corporation), decanoyl peroxide (eg, “Sanperox” -D manufactured by Sanken Kako Co., Ltd.)
PO), dicyclohexyl peroxydicarbonate (eg, “Sanperox” -CD manufactured by Sanken Kako Co., Ltd.), bis (4-t-butylcyclohexyl) peroxydicarbonate (eg, “Perloyl” TC manufactured by NOF Corporation)
P), t-butyl 2-ethylperhexanoate (for example, Perbutyl O manufactured by NOF Corporation), (1,1-dimethylpropyl) 2-ethylperhexanoate (for example, “Trigonox” 121 manufactured by Kayaku Akzo) , (1,1-dimethylbutyl) 2-ethyl perhexanoate (for example, “Kayaester” HO manufactured by Kayaku Akzo Co., Ltd.), t-butyl 3,
5,5-trimethylperhexanoate (for example, "Perbutyl" 355 manufactured by NOF Corporation), O-isopropyl-OO- (1,1-dimethylbutyl) percarbonate (for example, "Perhexyl" I manufactured by NOF Corporation), OO- (t-butyl) -O-isopropyl carbonate (for example, "Perbutyl" I manufactured by NOF Corporation) and OO- (t-butyl) -O- (2-
Ethylhexyl) (for example, "Perbutyl" manufactured by NOF Corporation)
E), OO-t-butyl permaleate (eg, “Perbutyl” MA manufactured by NOF Corporation), t-butyl perlaurate (eg, “Perbutyl” L manufactured by NOF Corporation), t-butyl perbenzoate (Nippon Oil & Fats) "Perbutyl" Z) manufactured by the company can be used. These radical polymerization initiators may be used alone or as a mixture of two or more.

The resin composition A may contain the following components in addition to A1, A2, and A3.

In order to control the reactivity of the polymerization initiator (A3 component) which generates a radical by heating, a polymerization inhibitor or an accelerator can be added to the resin composition A.

As such a polymerization inhibitor, 2,6-di-
t-butyl-p-cresol, 2,2′-methylenebis (4-methyl-6-t-butylphenol), 2,2 ′
-Methylenebis (4-ethyl-6-t-butylphenol), 4,4'-thiobis (2-methyl-6-t-butylphenol), hydroquinone, 2-t-butylhydroquinone, 2,5-di-t-butyl Hydroquinone, p-benzoquinone, 2-ethylanthraquinone, dilaurylthiodipropionate, cuperone, and the like can be used.

As the accelerator, for example, a transition metal salt such as cobalt naphthenate can be used.

The resin composition A used in the present invention may contain a high molecular compound such as a thermoplastic resin, an elastomer or a thermoplastic elastomer. The addition of these polymer compounds has effects such as viscosity adjustment of the epoxy resin composition, prepreg tackiness adjustment, improvement in toughness of the cured product, and improvement in adhesion to reinforcing fibers.

The thermoplastic resin is not particularly limited, but those which can be easily dissolved in other components of the resin composition A are preferably used. Further, a thermoplastic resin that is insoluble in other components of the resin composition A can be preferably blended as long as it is finely divided. Specifically, acrylic resin, polyvinyl acetal, phenoxy resin, polyester, polycarbonate, polyarylene oxide, polysulfone, polyamide, and polyimide are preferably used.

The acrylic resin is a polymer of an acrylate ester or a methacrylate ester.
Polymethyl methacrylate. Commercially available products include "Delpet" (manufactured by Asahi Kasei Corporation) and "Acripet" (manufactured by Mitsubishi Rayon). Polyvinyl acetal is a resin obtained by acetalizing polyvinyl alcohol with a carbonyl compound such as formaldehyde or acetaldehyde, and polyvinyl formal or polyvinyl acetal can be used. Commercial products include "Denka Butyral"
And "Denka Formal" (manufactured by Denki Kagaku Kogyo Co., Ltd.) and "Vinilec" (manufactured by Chisso Corporation). Phenoxy resin is a resin obtained by condensing bisphenol A and epochlorohydrin.
AR "PKHP (manufactured by Union Carbide), etc. Polyester is a polymer having a carboxylic acid ester bond in the main chain. Commercially available products include" Vylon "(manufactured by Toyobo Co., Ltd.). Bisphenol A carbonate is a polymer having a carbonate bond in the main chain, and commercially available products include "PANLITE" (manufactured by Teijin Chemicals Ltd.).

Polyarylene oxide is a resin having a main chain structure in which aromatic divalent groups and oxygen atoms are alternately arranged. Commercially available products include "Noryl" (manufactured by General Electric). Polysulfone is a resin having a sulfonyl group in the main chain. In many cases, the main chain has an ether bond or the like. "Victrex" for commercial products
(Made by Mitsui Toatsu Chemicals, Inc.) and "UDEL" (made by Union Carbide). Polyamide is a resin having a carboxylic acid amide structure in the main chain. Commercial products include
"Macromelt" (manufactured by Henkel Hakusui Co., Ltd.) and "Amilan" CM4000 (manufactured by Toray Industries, Inc.) are available. Polyimide is a resin having a dicarboxylic imide structure in the main chain. Others may have an ether bond or an amide bond. Commercially available products include "Ultem" (manufactured by General Electric), "Matrimid" 5218 and the like.

Of these, polysulfone, polyarylene oxide and polyimide are preferably used for applications requiring both heat resistance and toughness. Polysulfone and polyvinyl formal have an effect of improving the adhesiveness to carbon fibers, and can improve interlayer shear strength, compressive strength, bending strength, and the like.

As the elastomer, a copolymer containing acrylonitrile and butadiene as raw materials is preferably used because of its excellent solubility. In particular, carboxyl groups,
It is particularly preferable to use a thermosetting resin such as an amino group or an epoxy group or a compound having a functional group capable of reacting with a curing agent thereof, since the effect of improving the toughness of the cured product is large.

Further, as another component of the resin composition A, particles containing an insoluble elastomer phase can be preferably used. Although crosslinked elastomer particles themselves can be used, core-shell type elastomer particles in which the surface of an epoxy resin-insoluble elastomer particle is coated with a non-elastomer component can be particularly preferably used. In this case, the component to be coated is preferably one that dissolves or swells like polymethyl methacrylate because the particles can be well dispersed in the epoxy resin. When particles containing such an insoluble elastomer phase are used, there is an advantage that the heat resistance of the cured resin is superior to that of a normal elastomer.

The addition of these elastomers has the effect of improving toughness. Particularly when fine core-shell type elastomer particles having a particle size of about 0.1 to 0.3 μm are blended,
The effect of improving toughness is remarkable.

As the thermoplastic elastomer, those which are easily dissolved in other components of the resin composition A are preferably used. Specifically, a block copolymer having a polyether structure as a soft segment and an aromatic polyester or an aliphatic polyamide structure as a hard segment is preferable. Commercially available polyester-based thermoplastic elastomers include Toray Dupont's "Hytrel", Toyobo's "Perprene", Akzo's "ARNITEL", General Electric's "LOMOND", and commercially available polyamide-based thermoplastic elastomers Hüls “VESTAMID”, ATOCHEM “PE”
BAX ”, EMS“ Greak A ”, Mitsubishi Kasei“ N ”
OVAMID "can be used. The addition of these thermoplastic elastomers has the effect of improving the toughness of the cured product. In addition, the heat resistance of the cured product is superior to the case where a normal elastomer is added.

The resin composition A used in the present invention may further contain inorganic particles such as silica, alumina, titanium oxide, zirconia, viscous minerals, talc, mica, and ferrite. These additions have the effect of imparting thixotropic properties to the uncured resin composition, the effect of improving the elastic modulus and heat resistance of the cured resin, and the effect of improving the wear resistance.
Further, particles of metal, carbon black, copper oxide, tin oxide and the like can be blended for improving conductivity.

In the present invention, in the step of impregnating the reinforcing fiber B with the resin composition A (step 1), the resin composition A is heated to impregnate the reinforcing fiber B simultaneously with the impregnation into the reinforcing fiber.
A prepreg is obtained by advancing a polymerization reaction of two components.

As such reinforcing fibers B, glass fibers,
Examples include carbon fiber, aramid fiber, and boron fiber. In order to obtain particularly excellent mechanical properties, carbon fibers, aramid fibers, and boron fibers are preferably used. The reinforcing fiber is
Since the volume content can be increased, a long fiber is preferably used. As the long fiber of the reinforcing fiber, various forms such as one strand, a bundle of a plurality of strands, a plurality of strands arranged in a parallel sheet, a woven fabric, a knit, and a braid may be used. it can.

The step of impregnating the reinforcing fiber B with the resin composition A (step 1) can be performed by several methods. A method in which a certain amount of the resin composition A is adhered to the reinforcing fiber B using a slit die, a reverse roll or a kiss roll, then sandwiched between sheets, rolls, endless belts, etc., and impregnated by applying heat and pressure. B, a method of impregnating the resin composition A by passing it through a heated die to which the resin composition A is supplied at a constant speed, two release papers coated with the resin composition B,
Alternatively, a method of sandwiching the reinforcing fibers B from above and below with a release paper coated with the resin composition A and a release paper not coated with the resin composition A and applying heat and pressure to impregnate the reinforcing fibers B can be used.

In the step 1, the heating is performed so that the decomposition of the A3 component proceeds, but the curing reaction of the A1 component does not substantially occur. Usually, in order to reduce the viscosity of the resin composition, the reaction is performed by heating to a temperature at which the reaction of the A1 component does not substantially occur, for example, 40 to 180 ° C. A substance that rapidly generates radicals at a temperature and time can be selected and used.

The heat applied in Step 1 decomposes the A3 component to generate radicals. The A2 component causes a polymerization reaction by the generated radical, and the viscosity of the resin composition increases. Once the A3 component is decomposed to generate radicals, the polymerization reaction of the A2 component proceeds even after passing through the step 1, so that a sufficient thickening effect can be obtained even when the time required for the step 1 is extremely short. The present inventors have found that The components A2 and A3 need not be completely reacted and consumed if the viscosity of the resin composition A is sufficiently increased.

In the step 1, although the A3 component is reacted, it is preferable that the A1 component is not substantially reacted because the pot life of the prepreg can be extended. Differential scanning calorimetry (DSC) can be used to find heat treatment conditions that do not substantially react the A1 component. When the heat history of the constant temperature is applied in the step 1 for a fixed time, the isothermal analysis of the A1 component is performed at the temperature used in the step 2, and a heat treatment time shorter than the time when the start of the heat generation of the A1 component may be used. When the heat treatment in the step 1 includes a temperature raising step, a similar temperature raising may be performed in the DSC to confirm that no heat is generated.

Also, DSC can be used to confirm that the A3 component reacts. Step 1
DSC measurement of the resin composition A with a heat history corresponding to
What is necessary is just to confirm the start of heat generation due to the decomposition of the A3 component and the polymerization of the A2 component. If the start of heat generation can be confirmed, it is not necessary to completely terminate the reaction of the decomposition of the A3 component and the polymerization of the A2 component within the range of the heat history.

Further, the increase in viscosity of the resin composition causes A3
Confirmation of the reaction of the components can also be performed. In this method, a heat history corresponding to step 1 is given to the resin composition A using a heating press or the like, and the viscosity at a specific temperature after being left for a while is measured and compared with the viscosity of the resin composition A without heat treatment. It is done by doing. As the value of the viscosity, a viscosity determined by a rotational viscometer or a complex viscosity determined by a dynamic viscoelasticity measuring device can be used. The effect of increasing the viscosity is preferably twice or more at a specific temperature according to the purpose of use. In any case, the heat treatment conditions in the step 1 can adopt the above-mentioned means, but are usually at 60 to 200 ° C. for 1 second to
One minute, preferably 3 seconds to 30 seconds at 80 to 180 ° C.

By subjecting the matrix resin in the prepreg obtained through the step 1 to a heat treatment,
Step of further promoting the polymerization reaction of component A2 (Step 2)
Can also be performed. In this case, the total of the time required for step 1 and the time required for step 2 is preferably within 1 minute.

The prepreg of the present invention produced through step 1 or steps 1 and 2 can be used in the same manner as a prepreg using a usual thermosetting resin to obtain a fiber-reinforced composite material.

The prepreg thus obtained was prepared by polymerizing a substantially unreacted thermosetting resin (component A1) and a radically polymerizable unsaturated compound (component A2) with the polymerization initiator. And the polymer forms a uniform phase with the thermosetting resin or exists as a continuous phase separated from the thermosetting resin. The polymer contained in the matrix resin of the prepreg contains a structure derived from the used polymerization initiator (A3) component. The structure derived from the A3 component means that when the A3 component is t-butyl perlaurate, a radical component generated by decomposition of the A3 component such as a t-butyloxy group and a lauroyl group is an unsaturated component of the A2 component. A structure incorporated into a polymer produced as a result of reacting with a bond.

As described above, it is preferable to use the A2 component containing 50 to 100% by weight of a compound having a plurality of radically polymerizable unsaturated compounds in the molecule. In this case, the polymer has a crosslinked structure, and forms a uniform phase with the thermosetting resin in the matrix resin of the prepreg, or exists as a continuous phase separated from the thermosetting resin. A polymer having a structure crosslinked by (co) polymerization of a compound having a plurality of radically polymerizable unsaturated bonds in a molecule,
For example, rubber particles and the like can be blended in the matrix resin of the prepreg. However, a polymer having a crosslinked structure cannot be dissolved in a thermosetting resin, and therefore can only be added in a particulate form. Therefore, such a prepreg is distinguished from the prepreg of the present invention by the form in which the polymer is present.

As an example of a simple method for confirming that such a polymer forms a uniform phase with the thermosetting resin in the matrix resin or exists as a continuous phase separated from the thermosetting resin, A method of extracting a thermosetting resin component from a prepreg using a suitable solvent and examining that the remaining polymer has a continuous form can be adopted.

The thermosetting resin component in the prepreg obtained according to the present invention hardly changes from the A1 component of the resin composition used for impregnation. Therefore, when an epoxy resin composition is used as the A1 component and a particulate hardener or hardener is used as the component, these are found in the prepreg almost as they are. This means that, for example, microscopic observation or immersion of the prepreg in an appropriate solvent that dissolves only the epoxy resin, the reinforcing fiber and the polymer derived from the A2 component are separated by a wire mesh or the like, and the filtrate is further filtered with a filter paper or membrane. It can be confirmed by filtering with a filter or the like to obtain particles of a curing agent or a curing assistant.

The fiber-reinforced composite material is obtained by laminating a sheet-shaped prepreg, a tape-shaped or a string-shaped prepreg cut into a predetermined shape, and then heating and pressing. In particular, when forming a tubular article, lamination is performed by winding a prepreg around a mandrel. The method of heating and pressurizing is a method using an autoclave, a method using a vacuum bag and a heater, a method of applying pressure by wrapping a wrapping tape and heating in an oven, a method of winding a prepreg around a resin tube, putting it in a mold, and placing the mold. A method of heating and introducing high-pressure air into the resin tube to pressurize from the inside is used.

[0083]

The present invention will be described in more detail with reference to the following examples. In addition, the viscoelasticity data in Examples and the evaluation method of the tackiness of the prepreg were performed under the following conditions.

A. Dynamic Viscoelasticity The dynamic viscoelasticity was measured using a dynamic analyzer RDAII type manufactured by Rheometrics Co., Ltd., and the complex viscosity η * was determined at a temperature of 40 ° C. and a measurement frequency of 0.5 Hz.

B. DSC measurement The measurement was carried out using a Mettler DSC-30 as a measuring device.

C. Tackability of prepreg After the prepregs were pressed together, the peeling force was measured. This measurement method has many parameters such as applied stress, speed, and time. These may be appropriately determined in consideration of the state of using the prepreg and the like. Regarding the evaluation of tackiness in the present example, measurement was performed under the following conditions using "Instron" (registered trademark) 4201 universal tester (manufactured by Instron Japan) as a measuring device.・ Environment: 23.2 ° C., 50 ± 5% RH ・ Sample: 50 × 50 mm ・ Load speed: 1 mm / min. -Adhesive load: 0.12 MPa-Load time: 5 ± 2 sec-Peeling speed: 10 mm / min. Example 1 Preparation of Matrix Resin The following raw materials were mixed to prepare a resin composition (1).

Bisphenol A type epoxy resin 40 parts by weight Bisphenol A type solid epoxy resin 25 parts by weight Phenol novolak type epoxy resin 35 parts by weight Dicyandiamide 4 parts by weight DCMU 4 parts by weight Polyvinyl formal 3 parts by weight DSC of this resin composition (1) The measurement was performed under isothermal conditions of 140 ° C. The exothermic start time was 70 seconds.

Subsequently, the above resin composition (1) and the following raw materials were mixed to prepare a resin composition (2).

Resin composition (1) 111 parts by weight Bisphenol A diglycidyl ether methacrylic acid adduct 12 parts by weight 1,1,3,3-tetramethylbutyl 2-ethylperhexanoate 0.5 part by weight This resin composition When the complex viscosity of the object (2) was measured,
It was 2.3 × 10 ² Pa · s. This resin composition is
Insert between release papers and press with a press machine heated to 140 ° C.
Heat treatment was carried out for 0 seconds. The complex viscosity of the resin composition after the heat treatment was 4.5 × 10 ³ Pa · s.

2. Preparation of Prepreg The above resin composition (2) is applied on release paper so as to have a basis weight of 40 g / m ² . Subsequently, a prepreg is manufactured using the apparatus shown in FIG. Aligned in one direction, basis weight 125g / m
^2. A hot plate heated to 150 ° C. at a line speed of 10 m / min by sandwiching sheet-shaped carbon fiber “Treca” M40JB (manufactured by Toray Industries, Inc.) between release paper and release paper coated with a resin composition. 5, 7) and nip rolls (6, 8 in the figure) were heated and pressurized for impregnation to obtain a prepreg excellent in surface smoothness and tackiness. When the tackiness of the obtained prepreg was measured, it was 120 kPa.

Embodiment 2 1. Preparation of Matrix Resin The following raw materials were mixed to prepare a resin composition (3).

Bisphenol A type epoxy resin 40 parts by weight bisphenol A type solid epoxy resin 25 parts by weight phenol novolak type epoxy resin 35 parts by weight dicyandiamide 4 parts by weight DCMU 4 parts by weight polyvinyl formal 3 parts by weight pentaerythritol triacrylate 5 parts by weight 1, 0.5 parts by weight of 1,3,3-tetramethylbutyl 2-ethylperhexanoate When the complex viscosity of the resin composition (2) was measured,
It was 2.1 × 10 ² Pa · s. This resin composition is
Insert between release papers and press with a press machine heated to 140 ° C.
Heat treatment was carried out for 0 seconds. The complex viscosity of the resin composition after the heat treatment was 4.7 × 10 ³ Pa · s.

2. Preparation of Prepreg A prepreg having excellent surface smoothness and tack was obtained using the above resin composition (3) in the same manner as in Example 1. When the tackiness of the obtained prepreg was measured, it was 119 kPa.

[0094]

Comparative Example 4 Using the resin composition (1) described in Example 1, a prepreg having excellent surface smoothness but poor tackiness was obtained in the same manner as in Example 1. When the tackiness of the obtained prepreg was measured, it was 104 kPa.

[0096]

According to the present invention, it is possible to increase the resin viscosity after impregnation, and to provide a prepreg having excellent surface smoothness, handleability and resin flow during molding with high productivity. Can be.

[Brief description of the drawings]

FIG. 1 is a schematic view showing an example of a manufacturing apparatus used in a method of manufacturing a prepreg according to the present invention.

[Explanation of symbols]

 1: Creel 2: Comb 3: Release roll of release paper 4: Release roll of release paper coated with resin composition A 5, 7: Heating plate for heating 6, 8: Nip roll 9: Roll of release paper 10: Take-up roll of prepreg 101: Carbon fiber 102: Release paper 103: Release paper coated with resin composition A 104: Prepreg

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI C08L 63/00 C08L 63/00 // C08G 59/44 C08G 59/44 B29K 63:00 105: 08

Claims (8)

[Claims] 1. A resin composition A comprising a thermosetting resin composition (A1), a radically polymerizable unsaturated compound (A2), and a polymerization initiator (A3) which generates a radical by heating as essential components, and a reinforcing fiber. In the step of impregnating B (step 1),
A method for producing a prepreg, wherein the polymerization reaction of the A2 component is advanced by heating the resin composition A. 2. The method according to claim 1, wherein in step 1, the A3 component reacts to generate a radical, but the A1 component does not substantially react. 3. The method for producing a prepreg according to claim 1, wherein the time required for the step 1 is 1 minute or less. 4. The method for producing a prepreg according to claim 1, wherein the time required for the step 1 is 30 seconds or less. 5. The prepreg according to claim 1, wherein the A2 component of the resin composition A contains at least 50% by weight of a compound having a plurality of radically polymerizable unsaturated bonds. Method. 6. The method for producing a prepreg according to claim 1, wherein the A1 component of the resin composition A is a resin composition comprising an epoxy resin and a curing agent. 7. The method for producing a prepreg according to claim 6, wherein the curing agent is at least one particulate curing agent selected from dicyandiamide, imidazole derivatives, organic acid hydrazides and aromatic amines. 8. The curing agent is a particulate curing agent made of dicyandiamide, and the A1 component contains a particulate curing aid made of a urea derivative or an imidazole derivative substituted with an aryl group. Claim 6 or 7
A method for producing the prepreg according to the above.