JP4546743B2 - Drawing resin composition, fiber reinforced resin composition, molding method thereof and molded article - Google Patents

Description

  The present invention relates to a resin composition for pultrusion molding, a fiber reinforced resin composition, a molding method thereof, and a molded product.

  In general, thermosetting resins such as unsaturated polyester resins, vinyl ester resins and epoxy resins have excellent mechanical strength and water resistance and chemical resistance when combined with fiber reinforcements such as glass fibers, carbon fibers and aramid fibers. A fiber-reinforced composite material having excellent properties can be produced.

  The fiber reinforced composite material using a thermosetting resin as a matrix resin includes hand lay-up molding, resin injection molding, resin transfer molding (RTM) molding, filament winding (FW) molding, and bulk molding compound. There are (BMC) molding, sheet molding compound (SMC) molding, pultrusion molding and the like. Among them, the pultrusion method generally includes a step of impregnating a fiber base material with a resin composition to which a heat curing catalyst is added and then heat-curing in a mold, and the pultrusion method is industrially produced. In order to perform well, it is important to let this process pass continuously and regularly. In addition, in order to smoothly pull out a molded product having a smooth surface from the mold, the resin impregnated into the fiber base material can be in close contact with the mold until it is sufficiently cured, or it can be pressed with an appropriate pressure. is necessary. However, if the drawing speed is increased to improve productivity, the molded product will be drawn out from the mold while the resin composition is not sufficiently cured. This makes it difficult to perform regular operations due to the residual resin, or to cause a problem that the resin is cut during drawing to cause defects in the molded product. For this reason, in order to improve productivity in the pultrusion molding, a resin composition having an excellent rapid curability that can be sufficiently cured in the mold or immediately after exiting the mold even if the mold is drawn at a high speed. It is important to use.

The resin used for such pultrusion molding is easy to handle, that is, the pot life of the resin containing the curing agent at normal temperature, the excellent quick curability, and the machine of the molded product obtained Radical curable thermosetting resins such as unsaturated polyester resins and vinyl ester resins are widely used because of their excellent mechanical strength and water resistance.
However, radical curable thermosetting resins such as unsaturated polyester resins and vinyl ester resins have excellent rapid curability, but the volume shrinkage of the cured resin is as large as 7 to 8%. Therefore, when pultrusion molding is performed, a crack is generated in the obtained molded product, or a defect is generated that causes cracking in a bending stress state.

For the purpose of preventing defects such as cracks and chips in the molded product, various thermoplastic resins, for example, thermoplastic resins such as polystyrene, polyvinyl acetate, styrene butadiene rubber and polyolefin are generally blended as a low shrinkage agent. It is.
However, these low shrinkage agents have a function of relaxing the stress generated during molding by generating microcracks and voids in the cured resin, but microcracks and voids are present in the resin composition. As a result, the molded product loses transparency due to irregular reflection of light.
In addition, when molding with the addition of a colorant such as toner, the toner is less likely to develop color due to the presence of the above-described microcracks and voids. It is difficult to obtain uniform colorability because defects in various molding appearances such as these are likely to occur.
Further, due to the influence of microcracks and voids present in the cured resin resulting from the blending of the low shrinkage agent, the physical properties of the cured resin are clearly lower than those not blended with the low shrinkage agent.

For the purpose of solving defects in the appearance of the cured resin by blending such a low shrinkage agent, a thermosetting resin such as unsaturated polyester and vinyl ester resin and various heats blended as a low shrinkage agent. Various methods for significantly improving the compatibility of the two components with the plastic resin and adding a compatibilizer as the third component have been studied.
For example, Patent Document 1 shows an example in which a graft copolymer obtained by bonding a chain made of a polyoxyalkylene ether to a chain obtained by a polymerization reaction containing a styrene monomer as a main component is used as a compatibilizing agent. Yes.
Although this compatibilizing agent shows a high compatibilizing effect and can maintain a stable dispersion state for a long time, it cannot solve the problem of deterioration of physical properties due to the incorporation of a low shrinkage agent.

On the other hand, epoxy resin, which is another typical thermosetting resin, does not need to contain a low shrinkage agent because the volume shrinkage of the resin cured product is as small as 1 to 2%. Compared to ester resins and the like, it has excellent adhesion to fiber reinforcements, particularly carbon fibers. Accordingly, the epoxy resin is widely used as a carbon fiber reinforced composite material in the aerospace field, the automobile application field, the railway application field, and the sports field that require characteristics such as high strength, high elasticity, and light weight.
However, these carbon fiber reinforced composite materials are molded by using a prepreg sheet, which is a sheet-like intermediate base material in which fibers are impregnated with a resin, and take several hours at a temperature of 100 ° C. or higher. Since most methods are cured, it is not suitable for a resin composition for pultrusion molding that requires fast curability.

JP 2001-213967 A

  Therefore, an object of the present invention is to provide a resin composition for pultrusion molding, a fiber reinforced resin composition, and a molding method thereof that do not contain a low shrinkage agent and are excellent in colorability, appearance, and physical properties even when pultrusion molding is performed. And providing a molded article.

The present invention relates to an epoxy group-containing vinyl ester obtained by reacting an ethylenically unsaturated carboxylic acid in an amount of 0.2 to 0.7 equivalent to 1 equivalent of an epoxy group of an epoxy resin having two or more epoxy groups. Resin (A), styrene, vinyl styrene, chlorostyrene, methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, hexyl (meth) acrylate, decyl (meth) acrylate, lauryl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, glycidyl methacrylate, dicyclopentenyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, allyl methacrylate, ethylene glycol di (meth) Acrylate, propylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, glycerin tri (meth) acrylate, From glycerin di (meth) acrylate, trimethylolethane tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolethane di (meth) acrylate, pentaerythritol tetra (meth) acrylate, pentaerythritol tri (meth) acrylate radically polymerizable monomer and / or allyl glycidyl ether is selected, phenyl glycidyl ether, butyl glycidyl ether, 2- From tilhexyl glycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, resorcin diglycidyl ether Selected epoxy diluent (B), organic peroxide (C), epoxy resin curing agent (D) based on acid anhydride, microcapsule type latent curing accelerator, heat curing type Selected from imidazoles, amine adduct type latent curing accelerators, organic acid salts of strong base compounds, onium salts, urea adduct type latent curing accelerators and hydrazide type latent curing accelerators A latent epoxy resin curing accelerator (E) which is a mixture with one or more kinds, and the amount of the radical polymerizable monomer and / or epoxy diluent (B) is the epoxy group-containing vinyl ester resin ( The resin composition for pultrusion molding is characterized by being 10% by mass to 50% by mass with respect to A) .
Moreover, this invention is a fiber reinforced resin composition characterized by including the said resin composition for pultrusion molding, and a fiber reinforcement.
Furthermore, this invention is a pultrusion method characterized by performing the pultrusion molding of the said fiber reinforced resin composition on the conditions of the drawing speed of 30-120 cm / min, and the temperature of 100-200 degreeC.

  According to the present invention, since an epoxy group-containing vinyl ester resin obtained by reacting an epoxy resin and an ethylenically unsaturated carboxylic acid in a predetermined quantitative ratio is used, a low shrinkage agent is not blended and the drawing is performed. Even if it shape | molds, the resin composition for pultrusion molding excellent in coloring property, an external appearance, and a physical property, a fiber reinforced resin composition, its molding method, and a molded article can be obtained.

  The resin composition for pultrusion molding of the present invention is obtained by reacting 0.2 to 0.7 equivalents of ethylenically unsaturated carboxylic acid with respect to 1 equivalent of epoxy groups of an epoxy resin having two or more epoxy groups. The resulting epoxy group-containing vinyl ester resin (A), radical polymerizable monomer and / or epoxy diluent (B), organic peroxide (C), and epoxy resin curing agent mainly composed of acid anhydride ( D) and a latent epoxy resin curing accelerator (E).

  The epoxy group-containing vinyl ester resin (A) is obtained by reacting an epoxy resin and an ethylenically unsaturated carboxylic acid at a predetermined ratio.

  The epoxy resin only needs to have two or more epoxy groups in the molecule, and examples thereof include bisphenol-type epoxy resins and novolac-type epoxy resins, which include glycidyl ether obtained by condensation of bisphenol and epihalohydrin. , Novolak-type glycidyl ether obtained by condensation of phenol and cresol novolak with epihalohydrin, halogenated bisphenol and halogenated glycidyl ether obtained by condensation of epihalohydrin, diaminodiphenylmethane, diaminodiphenylsulfone or aminophenol, and epihalohydrin Obtained by condensation of amine-type glycidyl ether, cyanuric acid or isocyanuric acid and epihalohydrin obtained by condensation with Glycidyl ester obtained by condensation of polybasic acid such as triazine type glycidyl ether, phthalic acid, terephthalic acid and isophthalic acid and epihalohydrin, glycidyl ether obtained by condensation of alkylene oxide adduct of bisphenol and epihalohydrin or these The combination of is mentioned.

  It is preferable that the epoxy equivalent of an epoxy resin is 100-1000. When the epoxy equivalent is less than 100, it is not preferable because the physical properties, particularly flexibility, of the cured resin product tends to decrease. On the other hand, when the epoxy equivalent exceeds 1000, the viscosity of the resin composition becomes high. For example, when glass fiber is contained, the impregnation property to the glass fiber tends to decrease, which is not preferable.

  As the ethylenically unsaturated carboxylic acid, acrylic acid, methacrylic acid, crotonic acid, cinnamic acid and the like can be used, and acrylic acid and methacrylic acid are preferable from the viewpoint of reactivity with the epoxy resin.

  The compounding amount of the ethylenically unsaturated carboxylic acid is determined by the equivalent ratio with the epoxy group in the epoxy resin, and the ethylenically unsaturated carboxylic acid is 0.2 to 0.7 with respect to 1 equivalent of the epoxy group of the epoxy resin. The equivalent is preferable, and 0.4 to 0.7 is more preferable. If the blending amount of the ethylenically unsaturated carboxylic acid is less than 0.2 equivalent, the curing rate of the resin composition becomes slow regardless of the type of curing agent for the epoxy resin, which is not preferable. On the other hand, if it exceeds 0.7 equivalents, volume shrinkage of the cured resin becomes large, and cracks and chips are likely to occur during molding, which is not preferable. Furthermore, for example, when mixed with a fiber reinforcing material, a difference in adhesion between the fiber reinforcing material and the resin interface cannot be obtained as compared with a normal vinyl ester resin.

By reacting the epoxy resin with the ethylenically unsaturated carboxylic acid at such an equivalent ratio, an unreacted epoxy group remains in the resin, and 0.8 to 0.3 equivalent (preferably, 0.6 to 0.3 equivalent) epoxy group and 0.2-0.7 equivalent (preferably 0.4-0.7 equivalent) ethylenically unsaturated carboxylic acid ester group coexisting epoxy group-containing vinyl ester resin (A).
The weight average molecular weight of the epoxy group-containing vinyl ester resin (A) is preferably 300 to 5,000. If the weight average molecular weight is less than 300, the cured resin becomes too hard and the toughness becomes poor, such being undesirable. On the other hand, if it exceeds 5000, the viscosity of the resin composition increases, and workability and impregnation into a fiber reinforcing material decrease, which is not preferable.

  The reaction temperature between the epoxy resin and the ethylenically unsaturated carboxylic acid is not particularly limited, and is usually preferably in the range of 90 ° C to 130 ° C. If the reaction temperature is less than 90 ° C., the reaction is slow, and the reaction does not proceed beyond a certain amount over time. On the other hand, when the temperature exceeds 130 ° C., it is not preferable because a side reaction product is easily generated and gelation may occur during the reaction.

  In order to smoothly advance the reaction between the epoxy resin and the ethylenically unsaturated carboxylic acid, a known esterification catalyst can be used. Examples of esterification catalysts include tertiary amines such as toluethylamine and dimethylbenzylamine, quaternary ammonium salts such as trimethylbenzylammonium chloride and triethylbenzylammonium salts, imidazole derivatives such as imidazole and 2-methylimidazole, triethylphosphine, and tributyl. Trialkylphosphines such as phosphine and tri-n-butylphosphine; triphenylphosphine, tri (methylphenyl) phosphine, tri (hydroxyphenyl) phosphine, tri (nonylphenyl) phosphine, diphenyltolylphosphine, tri-m-tolyl Triarylphosphines such as phosphine and tris (2,6-methoxyphenyl) phosphine; triorganophosphines such as triphenylphosphine and triphenylborane Compounds, organic neighboring compounds such as quaternary phosphonium salts such as tetraphenylphosphonium / tetraphenylborate, benzyltriphenylphosphonium chloride, ethyltriphenylphosphonium bromide, organic acid metal salts such as chromium naphthenate, zinc naphthenate, lithium naphthenate Etc. These esterification catalysts can be appropriately selected depending on the purpose, and can be used alone or in combination of two or more.

  The blending amount of the esterification catalyst is preferably 0.01 to 5.0 parts by mass, more preferably 0.05 to 2.0 parts by mass with respect to 100 parts by mass in total of the epoxy resin and the ethylenically unsaturated carboxylic acid. If the blending amount is less than 0.01 parts by mass, the reaction is slow, and the reaction does not proceed beyond a certain amount over time, which is not preferable. On the other hand, if the blending amount exceeds 5.0 parts by mass, the calorific value at the time of reaction is high and a side reaction product is easily generated, and since there are many esterification catalysts after the reaction, the curing characteristics are not stable, and the resin It is not preferable because the physical properties of the cured product are not stable.

In addition, the epoxy group-containing vinyl ester resin (A) includes known hydroquinone, monomethylhydroquinone, t-butylhydroquinone, p-benzoquinone, copper salt and the like for the purpose of adjusting gelation prevention, storage stability and radical polymerization rate during the reaction. The polymerization inhibitor can be used.
The blending amount of the polymerization inhibitor is preferably 0.001 to 1.0 part by mass and more preferably 0.01 to 0.5 part by mass with respect to 100 parts by mass in total of the epoxy resin and the ethylenically unsaturated carboxylic acid. If the blending amount is less than 0.001 part by mass, the radical scavenging action during the reaction is small and gelation tends to occur, which is not preferable. On the other hand, when the amount exceeds 1.0 part by mass, the reaction is slow, and even if it takes a long time, the reaction does not proceed beyond a certain amount and a large amount of unreacted material remains, which is not preferable.

Furthermore, from the viewpoint of suppressing bubble generation at the time of mixing and stirring with the curing agent performed before molding, and reducing drawing resistance due to adhesion and adhesion to the mold, silicon-based, fluorine-based, fatty acid ester-based, etc. Surfactants can be used.
The blending amount of the surfactant is preferably 0.01 to 0.5 parts by mass with respect to a total of 100 parts by mass of the epoxy resin and the ethylenically unsaturated carboxylic acid from the viewpoint of obtaining a desired effect as the surfactant. If the blending amount is less than 0.01 parts by mass, the drawing resistance of the resin composition will increase, such being undesirable. On the other hand, if it exceeds 0.5 parts by mass, the surfactant will bleed, which is not preferable.

The epoxy group-containing vinyl ester resin (A) is diluted with a radical polymerizable monomer and / or an epoxy diluent (B) in order to lower the viscosity and improve the impregnation of the fiber reinforcement or the like.
Examples of the radical polymerizable monomer (B) include vinyl monomers such as styrene, vinyl styrene, and chlorostyrene, and methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, hexyl (meth) acrylate, and decyl (meta). ) Acrylate, lauryl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, glycidyl methacrylate, dicyclopentenyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, allyl meta Acrylate, ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, dipropylene glycol di (meth) a Relate, hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, glycerin tri (meth) acrylate, glycerin di (meth) acrylate, trimethylolethane tri (meth) acrylate, trimethylolpropane tri (meth) acrylate And (meth) acrylate monomers such as trimethylolethane di (meth) acrylate, pentaerythritol tetra (meth) acrylate, and pentaerythritol tri (meth) acrylate.

  Examples of the epoxy diluent (B) include known monofunctional epoxy diluents such as allyl glycidyl ether, phenyl glycidyl ether, butyl glycidyl ether, and 2-ethylhexyl glycidyl ether, neopentyl glycol diglycidyl ether, and 1,6-hexane. Examples include polyfunctional epoxy diluents such as diol diglycidyl ether, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, and resorcin diglycidyl ether.

Such radically polymerizable monomers (B) and epoxy diluents (B) can be used alone or in combination.
The blending amount of the radical polymerizable monomer and / or the epoxy diluent (B) is preferably 10% to 50%, more preferably 15 to 35% by mass ratio with respect to the epoxy group-containing vinyl ester resin (A). When the blending amount is less than 10%, the resin composition has a high viscosity, which is not preferable because workability and impregnation into a fiber reinforcing material are deteriorated. On the other hand, if it exceeds 50%, the cured resin will not reach a sufficient hardness, which is not preferable.

  In order to completely cure the epoxy group-containing vinyl ester resin (A) and the radical polymerizable monomer and / or the epoxy diluent (B), an organic peroxide (C), an epoxy resin curing agent (D), and a potential An epoxy resin curing accelerator (E) is used in combination.

Organic peroxides (C) are used to cure ethylenically unsaturated groups and radical polymerizable monomers such as benzoyl peroxide, dimyristyl peroxydicarbonate, dicumyl peroxide, 1,1-bis (t- Butylperoxy) -3,3,5-trimethylsiloxane, lauroyl peroxide, cyclohexanone peroxide, t-butylperoxy-2-ethylhexanoate, t-hexylperoxy-2-ethylhexanoate, t-butylperoxybenzoate, bis Redox such as (4-t-butylcyclohexyl) peroxydicarbonate, ketone peroxides and cobalt salts such as methyl ethyl ketone peroxide, cumene hydroperoxide and manganese salts, benzoyl peroxide and dimethylaniline Systems hardeners and combinations thereof.
The blending amount of the organic peroxide (C) is usually preferably 0.1 to 5.0 parts by mass with respect to 100 parts by mass of the mixture of (A) and (B). If the blending amount is less than 0.1 parts by mass, the polymerization reaction does not proceed sufficiently, and sufficient heat resistance and strength of the resin cured product cannot be obtained. On the other hand, when the amount exceeds 5.0 parts by mass, no improvement in reactivity due to an increase in the blending amount is observed, and conversely, the plastic component in the remaining curing agent may cause a decrease in physical properties, which is not preferable.

The epoxy resin curing agent (D) is used for curing the epoxy group and the epoxy diluent. Epoxy resin curing agent (D) is an acid anhydride from the standpoints of excellent curability at medium to high temperatures, little coloration during curing, a highly transparent cured product, and low volume shrinkage of the cured product. For example, phthalic anhydride, maleic anhydride, itaconic anhydride, succinic anhydride, trimellitic anhydride, pyromellitic anhydride, hexahydrophthalic anhydride, tetrahydrophthalic anhydride, methyl nadic anhydride Acid, methyltetrahydrophthalic anhydride, benzophenonetetracarboxylic anhydride, methylhexahydrophthalic anhydride, methylcyclohexenetetracarboxylic anhydride, and the like and combinations thereof can be used.
The blending amount of the epoxy resin curing agent (D) is preferably 0.7 to 1.3 equivalents relative to 1 equivalent of epoxy groups of the epoxy resin of the epoxy group-containing vinyl ester resin (A), and 0.9 to 1 .1 equivalent is more preferred. When the blending amount is less than 0.7 equivalent, the volume shrinkage of the cured resin becomes large, which is not preferable. On the other hand, when the amount exceeds 1.3 equivalents, unreacted acid anhydride remains in the cured resin and the water resistance and chemical resistance of the cured resin are deteriorated.

As an epoxy resin hardening accelerator, a latent epoxy resin hardening accelerator (E) is used from a viewpoint of improving productivity and the hardening rate at the time of a heating. In particular, a thermosetting latent epoxy resin curing accelerator (E) that is relatively stable at room temperature to about 50 ° C., hardly reacts, and is activated at about 80 ° C. to start the reaction is preferable.
Examples of such epoxy resin curing accelerators (E) include heat-curing imidazoles, amine adduct type latent curing accelerators, strong acid base organic acid salts, onium salts, and urea adduct type latent curing accelerators. And a combination of hydrazide-based latent curing accelerators.

  Examples of imidazoles include 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 2-phenylimidazole, 1-benzyl-2-methylimidazole, 1-cyanoethyl- 2-methylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-phenyl-imidazole, 1-cyanoethyl-2-undecylimidazolium trimelli Tate, 1-cyanoethyl-2-phenylimidazolium trimellitate and the like.

The amine adduct type latent curing accelerators are compounds obtained by reacting a commercially available epoxy resin and an amine compound, and the stability of the resin composition is significantly improved as compared with the case where the amine compound is used alone. Moreover, although it is a solid insoluble in a liquid general epoxy resin around room temperature, it is solubilized by heating.
Specifically, the amine adduct type latent curing accelerators have at least one active hydrogen capable of undergoing an addition reaction with an epoxy group of a monofunctional and polyfunctional epoxy compound, and are classified into primary, secondary, tertiary, It is a reaction product with an amine compound having at least one substituent selected from a primary amino group in one molecule. Such epoxy compounds and amine compounds include aliphatic, alicyclic, aromatic and heterocyclic epoxy compounds and amine compounds.
As such amine adduct type latent curing accelerators, for example, Ajinomoto Co. Amicure PN-23, MY-24, and the like can be used.

Organic acid salts of strong base compounds include phenols, octylic acid, strong basic compounds such as 1,8-diazabicyclo (5,4,0) -undecene-7, 2,4,6-tris (dimethylaminomethyl) phenol. Examples include organic acid salts of formic acid, toluenesulfonic acid, and phthalic acid. By taking the structure of the salt, the stability of the resin composition is remarkably improved as compared with the conventional tertiary amine.
Organic acid salts of such strong base compounds are, for example, U-CAT SA1, U-CAT SA102, U-CAT SA603, U-CAT SA506 of San Apro Co., Ltd., and PI IT Japan Co., Ltd. K-61B or the like can be used.

  Since onium salts are excellent in balance between curing characteristics upon heating and stability at room temperature, they can be preferably used. For example, antimony pentachloride-acetyl chloride complex, diaryliodonium salt, boron halide-tertiary amine adduct, benzyl Examples thereof include a sulfonium salt, a benzylammonium salt, a pyridinium salt, a benzylsulfonium salt, and a hydrazinium salt.

  Urea adduct-type latent curing accelerators are solids that are insoluble in general epoxy resins at room temperature, but sublimate at a temperature of about 80 ° C. or higher, and urea directly bonded to an aromatic ring such as a benzene ring. A compound having a bond. The aromatic ring may have a substituent such as alkyl or halogen. Examples of the urea adduct type latent curing accelerators include N-phenyl-N ′, N′-dimethylurea, N- (4-chlorophenyl) -N ′, N′-dimethylurea, N- (3,4). -Dichlorophenyl) -N ', N'-dimethylurea, N- (3-chloro-4-methylphenyl) -N', N'-dimethylurea, N- (3-chloro-4-ethylphenyl) -N ' , N′-dimethylurea, N- (3-chloro-4-methoxyphenyl) -N ′, N′-dimethylurea, N- (4-methyl-3-nitrophenyl) -N ′, N′-dimethylurea 2,4-bis (N ′, N′-dimethylureido) toluene, methylene-bis (pN ′, N′-dimethylureidophenyl) and the like.

As the hydrazide-based latent curing accelerator, various aliphatic, aromatic, alicyclic or heterocyclic dicarboxylic acid dihydrazides which are in a solid state near room temperature can be used, and aliphatic or heterocyclic dicarboxylic acid dihydrazides, For example, adipic acid dihydrazide, sebacic acid dihydrazide, dodecamethylene-1,12-dicarboxylic acid dihydrazide, octadecamethylene-1,18-dicarboxylic acid dihydrazide, 7,11-octadecadiene-1,18-dicarboxylic acid dihydrazide, 1, It is preferable to use 3-bis (hydrazinocarboethyl) -5-n-propylhydantoin, 1,3-bis (hydrazinocarboethyl) -5-isopropylhydantoin, and the like.
In addition, as such hydrazide-based latent curing accelerators, for example, Ajinomoto Fine Techno Co. Amicure VDH, Amicure UDH, and the like can be used.

Moreover, as an epoxy resin hardening accelerator (E), from a viewpoint of improving the pot life of a resin composition, a coating film (shell) will melt | dissolve by heating and the latent epoxy resin hardening accelerator of a core component ( It is more preferable to use a microcapsule-type latent epoxy curing accelerator in which the reaction of E) starts.
Examples of the core component of the epoxy resin curing accelerator (E) include amines, polyamides, imidazoles, ureas, hydrazides and the like, and epoxy adducts of these compounds. It is preferable because the cured resin has excellent heat resistance.

  Examples of the coating film include high molecular weight epoxy resin, polyurethane resin, polyethylene, polypropylene, polystyrene, nylon, polyester, polyvinyl chloride, and polyvinylidene chloride.

  As such a microcapsule type latent epoxy curing accelerator, Asahi Kasei's Novacure HX3721, HX3722, HX3613, HX3088, HX3741, HX3742, HX3748, HX3921HP, HX3941HP and the like can be used, for example. Further, from the viewpoint of obtaining a longer pot life, a type in which the coating film of the microcapsule type latent curing agent does not dissolve in the radical polymerizable monomer and / or the epoxy diluent (B) at 40 ° C. or lower, such as NovaCure HX3088 HX3741, HX3742, HX3748, HX3921HP, and HX3941HP are preferably used.

  Furthermore, as the latent epoxy resin curing accelerator (E), a microcapsule type latent epoxy curing accelerator is used from the viewpoint of improving productivity and curing rate during heating and further improving the pot life of the resin composition. It is particularly preferred to use a latent epoxy resin curing accelerator in combination. By doing so, it becomes possible to obtain superior productivity, fast curability and pot life, compared to the case where the microcapsule-type latent epoxy curing accelerator or latent epoxy resin curing accelerator is used alone.

The blending amount of the latent epoxy resin curing accelerator (E) is 0.05 parts by mass to 0.5 parts with respect to 100 parts by mass of the mixture of (A) and (B) from the viewpoint of curing speed and pot life. Part by mass is preferred.
Here, when the latent epoxy resin curing accelerator is used, the latent epoxy resin curing accelerator is dissolved in the component (B), particularly the radical polymerizable monomer, so that the curing reaction can be performed without applying heat. Be started. The blending amount of the latent epoxy resin curing accelerator having no solvent resistance to the component (B) is 0.05 parts by mass to 0 parts by mass with respect to 100 parts by mass of the mixture of (A) and (B). .2 parts by mass are preferred. If it exceeds 0.2 parts by mass, the curing reaction of the resin composition is too fast, and a sufficient pot life cannot be obtained.
On the other hand, when a microcapsule type latent epoxy resin curing accelerator is used, the curing reaction by heat can be controlled by selecting a coating film that is difficult to dissolve in the component (B). The pot life is stable even when an increased amount of the microcapsule type latent epoxy resin curing accelerator is added. As for the compounding quantity of such a microcapsule type | mold latent epoxy resin hardening accelerator, 0.1 mass part-0.5 mass part are preferable with respect to 100 mass parts of mixtures of (A) and (B). If it is less than 0.1 parts by mass, a sufficient curing rate cannot be expected, and the productivity in pultrusion decreases, which is not preferable.

  In addition, even when a large amount of the microcapsule type latent epoxy resin curing accelerator is not used, a faster curing system is obtained by using a latent epoxy resin curing accelerator in a range that does not shorten the pot life. be able to. The mixing amount of such a microcapsule-type latent epoxy resin curing accelerator and the latent epoxy resin curing accelerator is appropriately selected depending on the components and curing conditions of the resin composition to be obtained. From the viewpoint of 100 parts by mass of the mixture of (A) and (B), 0.1 to 0.4 parts by mass of the microcapsule type latent epoxy resin curing accelerator, other latent epoxy resin curing acceleration It is preferable that an agent is 0.05-0.1 mass part.

An arbitrary component can be added to the pultrusion resin composition according to the present invention as long as the desired effects of the present invention are not impaired.
For example, a filler can be further added from the viewpoint of increasing the elastic modulus and improving the dimensional stability. Examples of the filler include aluminum hydroxide, calcium carbonate, glass paroon, and glass flake. The compounding quantity of a filler can be used in 10 mass parts-50 mass parts with respect to 100 mass parts of mixtures of (A)-(E). When the amount is less than 10 parts by mass, the desired effect of the filler cannot be obtained, and when it exceeds 50 parts by mass, the viscosity of the resin composition increases, and the impregnation property to the fiber reinforcement is reduced. Absent.
Further, when performing pultrusion molding, from the viewpoint of smoothly removing the molded product from the mold, a zinc stearate, phosphate ester, fluorine-based releasing agent or the like can be used. The compounding quantity of a mold release agent can be used in 0.5 mass part-3.0 mass parts with respect to 100 mass parts of mixtures of (A) and (B). If the amount is less than 0.5 parts by mass, the desired effect of the release agent cannot be obtained, and if it exceeds 3.0 parts by mass, the adhesiveness at the interface between the resin composition and the fiber reinforcing material decreases. Therefore, it is not preferable.

  Further, from the viewpoint of obtaining a desired colored molded article, toner, dye, and the like can also be used. The blending amount of toner, dye, etc. can be used in the range of 3.0 to 15 parts by mass with respect to 100 parts by mass of the mixture of (A) and (B). If it is less than 3.0 parts by mass, the desired effect of toner, dye, etc. cannot be obtained, and if it exceeds 15 parts by mass, the curing rate of the resin composition will be slow, which is not preferable.

In the resin composition for pultrusion molding according to the present invention, an epoxy group-containing vinyl ester resin (A) and a radical polymerizable monomer and / or an epoxy diluent (B) are mixed in a predetermined ratio, and then the resulting mixture is mixed. An epoxy resin curing agent (D), a latent epoxy resin curing accelerator (E), other optional components, and finally an organic peroxide (C) are added and mixed by stirring.
The stirring and mixing method is not particularly limited, and for example, a hand mixer, a Henschel mixer, or the like can be used.

  The fiber reinforced resin composition of the present invention is characterized by including the pultrusion resin composition and a fiber reinforcing material.

Organic and / or inorganic fibers can be used as the fiber reinforcing material, and examples thereof include known glass fibers, carbon fibers, aramid fibers, polyethylene terephthalate fibers, vinylon fibers, and combinations thereof.
The compounding amount of the fiber reinforcement is preferably 50 to 70% in terms of the average volume content (volume fraction) of the fiber reinforcement in the molded product. If it is less than 50%, the rigidity of the molded product becomes poor, and if it exceeds 70%, a portion where the fiber reinforcing material is not impregnated with the resin composition is formed, which causes a decrease in physical properties of the molded product.
The mixing of the pultrusion resin composition and the fiber reinforcement is preferably performed by impregnating the fiber reinforcement with the pultrusion resin composition so that the resin composition adheres to the fiber reinforcement. Since it is necessary for the fiber reinforcing material to be able to withstand the pulling force at the time of pultrusion molding, for example, when trying to mold a rod material, the roving of the fiber reinforcing material is oriented in the drawing direction, and the mold material When a pipe material is to be molded, a chopped strand mat or the like is further used in combination, and the pipe is preferably used as a suitable structure such as laterally winding a roving.

Furthermore, the pultrusion method of the present invention is characterized in that the fiber reinforced resin composition is pultruded at a predetermined speed and temperature.
Here, the temperature at which the fiber-reinforced resin composition is applied is preferably 100 to 200 ° C. If it is less than 100 ° C., the fiber-reinforced resin composition is drawn out in an uncured state, and if it exceeds 200 ° C., a curing reaction occurs rapidly, which causes a crack in the molded product.
The drawing speed is preferably 30 to 120 cm / min. If the drawing speed is less than 30 cm / min, curing in the mold is completed at an early stage, so the resistance at the time of drawing increases and stable continuous molding cannot be performed, which may cause failure of the device. This is not preferable because of its properties. On the other hand, when the drawing speed exceeds 120 cm / min, the fiber-reinforced resin composition is drawn out in an uncured state, which is not preferable. Accordingly, the drawing time is preferably within a range of 0.5 to 3.0 minutes.
In pultrusion molding, for example, a fiber reinforced resin composition is continuously drawn into a heated mold, and the resin is subjected to a predetermined temperature and cured while passing through the mold, and a predetermined exit from the mold outlet is performed. Pull out in time.

Any apparatus can be used for the pultrusion method as long as it is a pultrusion apparatus that can be used for this purpose in the industry.
The mold is heated and controlled by a heater or the like, and it is more preferable to control the temperatures of the mold inlet and the other part of the mold separately. From the viewpoint of suppressing gelation of the fiber-reinforced resin composition squeezed at the inlet, the mold inlet temperature is preferably kept lower than the working temperature of the curing agent used. From the viewpoint of curing the fiber reinforced resin composition, the temperature of the other part of the mold is preferably set to be equal to or higher than the working temperature of the curing agent to be used. By dividing the heating zone into two or more stages, the fiber reinforced resin composition can be cured and shaped well by curing the fiber reinforced resin composition by subsequent heating while suppressing gelation in the vicinity of the inlet.
Since the molded product thus obtained has a small volume shrinkage, it does not contain a low shrinkage agent and is excellent in colorability, appearance and physical properties even when pultrusion is performed.

Examples 2 and 5 are reference examples.
[Example 1]
In a flask equipped with a thermometer, a stirrer and a reflux condenser, 186 g (1.0 equivalent) of bisphenol A type epoxy resin (Araldite AER2603 manufactured by Asahi Kasei Epoxy Co., Ltd., epoxy equivalent 189), 51.6 g (0.6 equivalent) of methacrylic acid Equivalent), 0.11 g of hydroquinone (1.0 × 10 ⁻³ equivalent), chromium naphthenate corresponding to 0.2 parts by mass with respect to 100 parts by mass in total of epoxy resin and methacrylic acid (chromium content 3%) 0 .48 g was added, heated to 100 ° C. while blowing air, and reacted for about 10 hours to obtain a reaction product having an acid value of 0 and a polystyrene-equivalent weight average molecular weight of 600. Styrene monomer was added to a mass ratio of 25% with respect to the whole reaction product to obtain a resin A-1 having a viscosity of 2.5 dPa · s (25 ° C.).
Resin A-1100 parts by weight, peroxyketal peroxide (Perhexa 3M manufactured by Nippon Oil & Fats Co., Ltd.) 1.5 parts by weight as an organic peroxide curing agent, peroxydicarbonate peroxide (Nippon Fats and Oil ( Co., Ltd. Parroyl TCP) 0.5 parts by mass, epoxy resin curing agent methyltetrahydrophthalic anhydride (Shin Nippon Rika Co., Ltd. Rikacid MT-500) for 1.0 equivalent of epoxy group of resin A-1 19.1 parts by mass equivalent to 0.9 equivalent, 0.3 parts by mass of a microcapsule type latent curing accelerator (Novacure HX3741 manufactured by Asahi Kasei Co., Ltd.), and an imidazole epoxy resin as a latent epoxy resin curing accelerator Curing accelerator (Curesol 2E4MZ manufactured by Shikoku Kasei Kogyo Co., Ltd.) 0.1 parts by mass, internal mold release agent (Mold with INT-E manufactured by Accel Plastic Co., Ltd.) 6) 1.0 part by weight, 10.0 parts by weight of gray toner (Rigolac Color RC82 Gray T manufactured by Showa Polymer Co., Ltd.) was mixed and stirred, and the resulting resin composition was put into a resin bath. did.
As the fiber reinforcement, 70 glass rovings # 4620 and ² glass continuous mats (300 / m ² ) above and below the glass fiber so that the volume content of the glass fiber in the molded product is about 65%. It was used. These fiber reinforcements were passed through the resin bath through a guide and led to a die. The fiber reinforced resin composition that has passed through the die is guided to a mold having a height of 3 mm, a width of 100 mm, and a length of 70 cm equipped with a heating device capable of setting two temperature zones, and the drawing speed is 90 cm / min. A pultruded product was obtained by performing pultrusion molding at an inlet temperature of 110 ° C. and a curing temperature of 160 ° C.

[Example 2]
100 parts by mass of the resin A-1 synthesized in Example 1, 1.5 parts by mass of a peroxyketal peroxide (Trigonox 22B-75 manufactured by Kayaku Akzo Co., Ltd.) as an organic peroxide curing agent, and peroxy 0.5 parts by mass of a dicarbonate-based peroxide (Perkadox 16 manufactured by Kayaku Akzo Co., Ltd.), methylhexahydrophthalic anhydride (Licacid MH-700 manufactured by Shin Nippon Rika Co., Ltd.) as an epoxy resin curing agent, 18.9 parts by mass equivalent to 0.9 equivalent to 1.0 equivalent of epoxy group of resin A-1, a microcapsule type latent curing accelerator (Novacure manufactured by Asahi Kasei Co., Ltd.) as a latent epoxy resin curing accelerator HX3742) 0.3 parts by mass, 1.0 part by mass of internal mold release agent (Mold with INT-EQ6 manufactured by Accel Plastic Co., Ltd.), gray toner (Rigola manufactured by Showa Polymer Co., Ltd.) A resin composition was obtained by mixing and stirring a mixture of 10.0 parts by weight of Kukura RC82 Gray T). This resin composition was put into a resin bath and subjected to pultrusion molding under the same conditions as in Example 1 to obtain a pultruded molded product.

[Example 3]
In the same experimental apparatus as in Example 1, 180 g (1.0 equivalent) of phenol novolac type epoxy resin (Epicron N740 manufactured by Dainippon Ink & Chemicals, Inc., epoxy equivalent 180), 28.8 g (0.4 equivalent) of acrylic acid ), Hydroquinone 0.06 g (0.6 × 10 ⁻³ equivalent), chromium naphthenate corresponding to 0.2 parts by mass with respect to a total of 100 parts by mass of epoxy resin and acrylic acid (chromium content 3%) 0. 44 g was added, heated to 100 ° C. while blowing air, and reacted for about 8 hours to obtain a reaction product having an acid value of 0 and a polystyrene-equivalent weight average molecular weight of 920. Styrene monomer was added at a mass ratio of 15% and butyl glycidyl ether was added at a mass ratio of 10% to give a resin A-2 having a viscosity of 5.0 dPa · s (25 ° C.).
Resin A-2 100 parts by mass, 1.5 parts by mass of diacyl peroxide peroxide (Cadox B-CH50, manufactured by Kayaku Akzo Co., Ltd.) as an organic peroxide curing agent, and methylhexahydro as an epoxy resin curing agent 39.8 parts by mass of phthalic anhydride (Rikacide MH-700, manufactured by Shin Nippon Rika Co., Ltd.), equivalent to 0.9 equivalent to 1.0 equivalent of epoxy group of resin A-2, latent epoxy resin curing As an accelerator, 0.3 mass part of microcapsule type latent curing accelerator (Asahi Kasei Co., Ltd. NovaCure HX3741), amine adduct type latent curing accelerator (Ajinomoto Co. Amicure PN-23) 0.1 mass Part, internal mold release agent (Mold with INT-EQ6 manufactured by Accel Plastic Co., Ltd.), gray toner (Rigorac Color RC82 Gray manufactured by Showa Polymer Co., Ltd.) -T) What added 10.0 mass parts was mixed and stirred, and the resin composition was obtained. The obtained resin composition was put into a resin bath and subjected to pultrusion molding under the same conditions as in Example 1 to obtain a pultrusion molded product.

[Example 4]
In the same experimental apparatus as in Example 1, 250 g (1.0 equivalent) of bisphenol A type epoxy resin (Epicoat 834 manufactured by Japan Epoxy Co., Ltd., epoxy equivalent 250), 43.0 g (0.5 equivalent) of methacrylic acid, hydroquinone 0.09 g (0.8 × 10 ⁻³ equivalents), benzyltriphenylphosphonium chloride corresponding to 0.3 parts by mass with respect to 100 parts by mass in total of epoxy resin and methacrylic acid (TPP- manufactured by Hokuko Chemical Co., Ltd.) ZC) 0.88 g was added, heated to 100 ° C. while blowing air, and allowed to react for about 12 hours to obtain a reaction product having an acid value of 0 and a polystyrene-equivalent weight average molecular weight of 1400. Styrene monomer was added to a mass ratio of 25% with respect to the whole reaction product to obtain a resin A-3 having a viscosity of 5.0 dPa · s (25 ° C.).
Resin A-3: 100 parts by mass of an alkyl peroxide ester peroxide (Trigonox 121-LS50 manufactured by Kayaku Akzo Co., Ltd.) as an organic peroxide curing agent, 2.0 parts by mass of methyl hexahydro as an epoxy resin curing agent 19.4 parts by mass of phthalic anhydride (Licacid MH-700, manufactured by Nippon Kayaku Co., Ltd.), equivalent to 0.9 equivalent to 1.0 equivalent of epoxy group of resin A-3, latent epoxy resin curing As an accelerator, 0.3 part by mass of a microcapsule type latent curing accelerator (Novacure HX3748 manufactured by Asahi Kasei Co., Ltd.), a phenol salt of 1,8-diazabicyclo (5,4,0) -undecene-7 (San Apro Co., Ltd.) U-CAT SA1) 0.1 parts by weight, internal mold release agent (Melwith INT-EQ6 made by Accel Plastics) 1.0 part by weight, gray toner (Showa High) To obtain a resin composition by mixing and stirring a material obtained by adding child Ltd. Rigorakku color RC82 Gray T) 10.0 parts by mass. The obtained resin composition was put into a resin bath and subjected to pultrusion molding under the same conditions as in Example 1 to obtain a pultrusion molded product.

[Example 5]
100 parts by mass of the resin A-1 synthesized in Example 1, 1.5 parts by mass of a peroxyketal peroxide (Trigonox 22B-75 manufactured by Kayaku Akzo Co., Ltd.) as an organic peroxide curing agent, and peroxy 0.5 parts by mass of a dicarbonate-based peroxide (Perkadox 16 manufactured by Kayaku Akzo Co., Ltd.), methylhexahydrophthalic anhydride (Licacid MH-700 manufactured by Shin Nippon Rika Co., Ltd.) as an epoxy resin curing agent, 18.9 parts by mass equivalent to 0.9 equivalent to 1.0 equivalent of epoxy of resin A-1, imidazole type epoxy resin curing accelerator (Curesol manufactured by Shikoku Kasei Kogyo Co., Ltd.) as a latent heat epoxy resin curing accelerator 2E4MZ-CN) 0.3 parts by mass, internal mold release agent (Mold with INT-EQ6 manufactured by Accel Plastics) 1.0 part by mass, gray toner (Showa Polymer Co., Ltd.) ) Rigorak Color RC82 Gray T) Made with 10.0 parts by mass mixed and stirred to obtain a resin composition. The obtained resin composition was put into a resin bath and subjected to pultrusion molding under the same conditions as in Example 1 to obtain a pultrusion molded product. However, when the resin composition was molded the next day, the viscosity of the resin composition in the resin bath increased, and the pultruded product coming out from the mold exit had an unimpregnated portion of the resin. Therefore, the molding was interrupted at that time.

[Example 6]
To 100 parts by mass of the resin A-2 synthesized in Example 3, 1.5 parts by mass of peroxyketal peroxide (Trigonox 22B-75 manufactured by Kayaku Akzo Co., Ltd.) as an organic peroxide curing agent, peroxy 0.5 parts by mass of dicarbonate peroxide (Perkadox 16 manufactured by Kayaku Akzo Co., Ltd.), methyl nadic acid anhydride (methyl hymic anhydride manufactured by Hitachi Chemical Co., Ltd.) as an epoxy resin curing agent, resin 36.8 parts by mass corresponding to 0.9 equivalent to 1.0 equivalent of the epoxy group of A-2, a microcapsule type latent curing accelerator as a latent epoxy resin curing accelerator (Novacure HX3088 manufactured by Asahi Kasei Corporation) ) 0.3 parts by mass, urea adduct type latent curing accelerators N-phenyl-N ′, N′-dimethylurea 0.1 parts by mass, internal mold release agent Dowizu INT-EQ6) were mixed and stirred material obtained by adding 1.0 part by weight, the resulting resin composition was poured into a resin bath.
As the fiber reinforcing material, PAN-based carbon fiber (Besfight manufactured by Toho Tenax Co., Ltd., tensile strength 5000 MPa, tensile elastic modulus 240 GPa, linear density so that the volume content of carbon fiber in the molded product is about 68%. (800 Tex) 45 were used. These fiber reinforcements were passed through the resin bath through a guide and led to a die. The fiber reinforced resin composition that has passed through the die is led to a 6 mm inner diameter and 70 cm long mold equipped with a heating device that can set two temperature zones, and the inside of the mold is drawn at a drawing speed of 90 cm / min. Thus, a pultruded product was obtained (inlet temperature 110 ° C., curing temperature 160 ° C.).

[Example 7]
To the resin A-1100 parts by mass synthesized in Example 1, 2.0 parts by mass of a peroxide peroxide (Kayakaku AIC-75 manufactured by Kayaku Akzo Co., Ltd.) as an organic peroxide curing agent, an epoxy resin curing agent As methyltetrahydrophthalic anhydride (Ricacid MT-500 manufactured by Shin Nippon Rika Co., Ltd.), 19.1 parts by mass corresponding to 0.9 equivalent with respect to 1.0 equivalent of epoxy group of resin A-1, As epoxy resin curing accelerator, 0.3 part by mass of microcapsule type latent curing accelerator (Novacure HX3941HP manufactured by Asahi Kasei Co., Ltd.), aromatic sulfonium salt (Sun Aid SI-100L manufactured by Sanshin Chemical Industry Co., Ltd.) What added 05 mass part and 1.0 mass part of internal mold release agents (Moldwiz INT-EQ6 by Accel Plastics) was mixed and stirred, and the resin composition was obtained. The resulting resin composition was poured into a resin bath, subjected to pultrusion under the same conditions as the actual施例6 to give the pultrusion.

[Example 8]
In the same experimental apparatus as in Example 1, 250 g (1.0 equivalent) of bisphenol A type epoxy resin (Epicoat 834 manufactured by Japan Epoxy Co., Ltd., epoxy equivalent 250), 60.2 g (0.7 equivalent) of methacrylic acid, hydroquinone 0.09 g (0.8 × 10 ⁻³ equivalent), 0.93 g of chromium naphthenate (chromium content 3%) corresponding to 0.4 part by mass with respect to 100 parts by mass in total of epoxy resin and methacrylic acid The mixture was heated to 100 ° C. while blowing air and reacted for about 12 hours to obtain a reaction product having an acid value of 0 and a polystyrene-equivalent weight average molecular weight of 2800. Styrene monomer was added to a mass ratio of 30% with respect to the whole reaction product to obtain a resin A-4 having a viscosity of 6.0 dPa · s (25 ° C.).
Resin A-4 100 parts by mass, an organic peroxide curing agent, an alkyl perester peroxide (Trigonox 121-LS50, manufactured by Kayaku Akzo Co., Ltd.) 2.0 parts by mass, and an epoxy resin curing agent, anhydrous methyl nadic 10.9 parts by mass equivalent to 0.9 equivalent of 1.0 equivalent of epoxy group of Resin A-4, acid epoxy (Methyl Anhydric Acid manufactured by Hitachi Chemical Co., Ltd.), latent epoxy resin curing acceleration As an agent, 0.3 part by mass of a microcapsule type latent curing accelerator (Asahi Kasei Co., Ltd. NovaCure HX3742), 0.1 part by mass of a hydrazide type latent curing agent (Ajinomoto Fine Techno Co., Ltd. Amicure VDH), internal What added 1.0 mass part of mold release agents (Moldwiz INT-EQ6 by Accel Plastic Co., Ltd.) was mixed and stirred, and the resin composition was obtained. The obtained resin composition was put into a resin bath and subjected to pultrusion molding under the same conditions as in Example 1 to obtain a pultrusion molded product.

[Comparative Example 1]
In the same experimental apparatus as in Example 1, 250 g (1.0 equivalent) of bisphenol A type epoxy resin (Epicoat 834, manufactured by Japan Epoxy Co., Ltd., epoxy equivalent 250), 86 g (1.0 equivalent) of methacrylic acid, hydroquinone 0 .10 g (0.9 × 10 ⁻³ equivalent), 1.0 g of chromium naphthenate (chromium content 3%) corresponding to 0.3 part by mass with respect to 100 parts by mass in total of the epoxy resin and methacrylic acid, Heating to 100 ° C. while blowing air, reacting for about 15 hours, and when the acid value reached 15, the styrene monomer was added to a mass ratio of 30% with respect to the whole reaction product, and the polystyrene-converted weight average Resin B-1 having a molecular weight of 1900 and a viscosity of 6.3 dPa · s (25 ° C.) was obtained.
A pultrusion molding was carried out under the same conditions as in Example 1 except that the resin B-1 was used and an epoxy resin curing agent and an epoxy resin curing accelerator were not used.

[Comparative Example 2]
Resin B-1 is used, an epoxy resin curing agent and an epoxy resin curing accelerator are not used, and a polystyrene-based low-shrinkage agent solution (Rigolac M5585, manufactured by Showa Polymer Co., Ltd.) as a low-shrinkage agent is 15.0 masses. Except for the partial use, pultrusion was performed under the same conditions as in Example 1 to obtain a pultruded product.

[Comparative Example 3]
In the same experimental apparatus as in Example 1, 186 g (1.0 equivalent) of bisphenol A type epoxy resin (Araldite AER2603, epoxy equivalent 189, manufactured by Asahi Kasei Epoxy Co., Ltd.), 8.6 g (0.1 equivalent) of methacrylic acid, hydroquinone 0.04 g (0.35 × 10 ⁻³ equivalents), triphenylphosphine (TPP manufactured by Hokuko Chemical Co., Ltd.) corresponding to 0.2 parts by mass with respect to 100 parts by mass in total of the epoxy resin and methacrylic acid. 40 g was added, heated to 100 ° C. while blowing air, and reacted for about 4 hours to obtain a reaction product having an acid value of 0 and a polystyrene-equivalent weight average molecular weight of 550. A styrene monomer was added to the reaction product at a mass ratio of 15% with respect to the whole reaction product to obtain a resin B-2 having a viscosity of 3.0 dPa · s (25 ° C.).
Resin B-2 100 parts by mass, 1.5 parts by mass of a diacyl peroxide peroxide (Nippa FF manufactured by Nippon Oil & Fats Co., Ltd.) as an organic peroxide curing agent, and methyltetrahydrophthalic anhydride (as an epoxy resin curing agent) 65.8 parts by mass equivalent to 0.9 equivalent of 1.0 equivalent of epoxy group of Resin B-2, and Rikacide MT-500 manufactured by Shin Nippon Rika Co., Ltd. as a latent epoxy resin curing accelerator Capsule type latent curing accelerator (Asahi Kasei Co., Ltd. NovaCure HX3748) 0.3 parts by mass, amine adduct type latent curing accelerator (Ajinomoto Co. Amicure PN-23) 0.2 parts by mass, internal mold release 1.0 parts by weight of agent (Mold with INT-EQ6 manufactured by Accel Plastic Co., Ltd.), gray toner (Rigolac Color RC82 Gray T manufactured by Showa Polymer Co., Ltd.) 10.0 What added the mass part was mixed and stirred, and the resin composition was obtained. The obtained resin composition was put into a resin bath, and pultrusion molding was performed under the same conditions as in Example 1. As a result, the pultruded product that came out from the mold outlet was sticky and the degree of curing was low. Therefore, molding was performed at a drawing speed of 20 cm / min to obtain a pultruded product.

[Comparative Example 4]
In the same experimental apparatus as in Example 1, 180 g (1.0 equivalent) of phenol novolak type epoxy resin (Dainippon Ink & Chemicals, Inc., Epicron N740, epoxy equivalent 180), 61.2 g (0.85 equivalent) of acrylic acid ), Hydroquinone 0.07 g (0.6 × 10 −3 equivalent), chromium naphthenate equivalent to 0.3 parts by mass (chromium content 3%) with respect to 100 parts by mass in total of epoxy resin and acrylic acid. 48 g was added, heated to 100 ° C. while blowing air, reacted for about 8 hours, and when the acid value reached 0, the styrene monomer was added to a mass ratio of 35% with respect to the whole reaction product, A resin B-3 having a polystyrene-reduced weight average molecular weight of 1050 and a viscosity of 3.5 dPa · s (25 ° C.) was obtained.
Resin B-3, 2.0 parts by weight of an alkyl perester peroxide (Trigonox 121-LS50 manufactured by Kayaku Akzo Co., Ltd.) as an organic peroxide curing agent, anhydrous as an epoxy resin curing agent as an epoxy resin curing agent 43.1 parts by weight of corresponding to 0.9 equivalents of methyl nadic (Hitachi Chemical Co., Ltd. anhydrous methylhymic Mick acid) the epoxy group 1.0 equivalent of resin B -3, latent epoxy resin curing 0.3 parts by mass of a microcapsule type latent curing accelerator (Novacure HX3088 manufactured by Asahi Kasei Co., Ltd.) as an accelerator, 0.1 parts by mass of an aromatic sulfonium salt (Sun Aid SI-100L manufactured by Sanshin Chemical Industry Co., Ltd.), 1.0 parts by mass of internal mold release agent (Melwith INT-EQ6 manufactured by Accel Plastic Co., Ltd.), gray toner (Rigolac Color RC82 manufactured by Showa Polymer Co., Ltd.) Leh T) 10.0 parts by weight were mixed by stirring to which was added to obtain a resin composition. The obtained resin composition was put into a resin bath and subjected to pultrusion molding under the same conditions as in Example 1 to obtain a pultrusion molded product.

[Comparative Example 5]
Except that the gray toner was not used, the same resin composition as in Comparative Example 1 was used, and pultrusion molding was performed under the same conditions as in Example 6 to obtain a pultruded product.

[Comparative Example 6]
Except that no gray toner was used, the same resin composition as in Comparative Example 3 was used and pultrusion molding was performed under the same conditions as in Example 6. As in Comparative Example 3, the pultruded product was cured. Since the degree of was low, molding was carried out at a drawing speed of 20 cm / min to obtain a pultruded product.

[Comparative Example 7]
Except that the gray toner was not used, the same resin composition as in Comparative Example 4 was used, and pultrusion molding was performed under the same conditions as in Example 6 to obtain a pultruded product.

Various physical property values of the pultruded resin composition and the pultruded product obtained therefrom were measured by the following methods.
1. Resin Epoxy Equivalent The epoxy equivalent of the resin was measured according to JIS K7236.
A sample corresponding to 6 × 10 ^{−4 to} 9 × 10 ⁻⁴ mol of epoxy group was weighed (W _r ) into a 1000 cm ³ flask, and 10 cm ³ of chloroform was added. After dissolving with a magnetic stirrer, the mixture was cooled to room temperature, and 20 cm ³ of acetic acid was added. Further, 10 cm ^{3 of} tetraethylammonium bromide acetic acid solution was added, and titration was performed with a perchloric acid acetic acid solution. The epoxy equivalent Es was calculated from the following formula (1).

E _e = 1000 × W _r / [(V _s −V ₀ ) × {1− (t ₀ −t _s ) / 1000}] × C _s (1)
E _e : Epoxy equivalent V _s : Amount of perchloric acid acetic acid solution consumed for titration by the end point (cm ³ )
V ₀ : Amount of perchloric acid acetic acid solution consumed for titration to the end point in the blank test (cm ³ )
t ₀ : Temperature of the perchloric acid acetic acid solution during the test and blank test (° C.)
t _s : temperature of perchloric acid acetic acid solution during standardization (° C.)
C _s : concentration of perchloric acid acetic acid solution at the time of standardization (mol / dm ³ )

2. Resin viscosity The resin viscosity was measured in accordance with JIS K 6901.
A 200 g sample was weighed into a 300 cm ³ tall beaker, allowed to stand in a thermostatic oven set at 25 ° C. for 90 minutes, and the viscosity was measured with a B-type viscometer.

3. Weight average molecular weight of resin The weight average molecular weight here is a polystyrene-converted value by the GPC method and is measured under the following conditions.
Apparatus: Showa Denko Co., Ltd., high-speed GPC apparatus GPC SYSTEM-21, Column: Showa Denko Co., Ltd., Shodex GPC LF804 connected in series, oven temperature: 40 ° C., eluent: tetrahydrofuran, sample concentration: 0.3% by weight, flow rate: 1 ml / min, injection amount: 0.1 ml Detector: RI (differential refractometer)

4). High-temperature curing characteristics The high-temperature curing characteristics were measured with reference to the measuring method of 130 ° C. constant temperature curing characteristics defined in JIS K 6901.
A predetermined amount of the curing agent was weighed into a 150 cm ³ beaker, 100 g of a sample was added thereto, and the mixture was well stirred with a glass rod until uniform. The beaker was covered with a watch glass and allowed to stand for 45 minutes, and then poured into a test tube to a height of 75 mm, and a thermocouple was fixed to the center of the sample. The test tube containing this sample is fixed to a constant temperature bath heated to a predetermined temperature so that the surface of the sample is 20 mm below the bath liquid level, and the time to reach the maximum exothermic temperature from 65 ° C and the maximum exothermic temperature are measured. did.
A resin composition having a predetermined maximum exothermic temperature and having a shorter time to reach the maximum exothermic temperature is excellent in fast curability.

5). Volume shrinkage The volume shrinkage of the resin was measured according to JIS K 6901.

6). Resin pot life 200 g of a sample containing a predetermined amount of curing agent is placed in a 300 cm ³ tall beaker, covered with a watch glass, and left in a constant temperature room at 40 ° C. After that, measure the viscosity with a B-type viscometer every 6 hours. If the viscosity change within 24 hours is less than 2 times the initial value, ○, gelled within 12 hours, or more than twice the expected value. The case where the viscosity increased was x, and the case where the gelation occurred within 12 to 24 hours, or the case where the viscosity increased more than twice the expected value was evaluated as Δ.

7). Molded Product Colorability A molded product formed by adding a toner was visually inspected, and a uniformly colored product was evaluated as ○, and a product with uneven color was evaluated as ×.

8). Appearance of molded product The obtained molded product was examined by visual inspection, and the case where a crack was observed was evaluated as “◯” and the case where no crack was observed was evaluated as “X”.

9. Glass transition temperature of fiber reinforced composite material A molded specimen was cut into a length of 60 mm, a thickness of 3 mm, and a width of 5 mm, and a dynamic viscoelasticity tester was used to raise the temperature at a rate of 2 ° C./min. ). The glass transition temperature was determined from the maximum value of the loss tangent (tan δ).

10. Bending strength of glass fiber reinforced composite material (GFRP) The bending strength of glass fiber reinforced composite material (GFRP) was evaluated according to JIS K 7017.

11. Interlaminar shear strength of glass fiber reinforced composite material (GFRP) Interlaminar shear strength of glass fiber reinforced composite material was evaluated according to JIS K 7057.

12 Bending strength of carbon fiber reinforced composite material (CFRP) The bending strength of carbon fiber reinforced composite material (CFRP) was evaluated according to JIS K 6913.
The molded product was cut into a length of 70 mm, and the diameter of the test piece was measured with a micrometer (Dp (mm)). The breaking load (P (N)) of the test piece was measured by setting the distance between fulcrums to 50 mm and the crosshead speed to 3.0 mm / min. The bending strength (σf (MPa)) of the composite material was calculated from the following formula (2).
σf = 400 × P × / (π × Dp ³ )

  The characteristics of the pultruded products obtained in Examples 1 to 8 are shown in Table 1, and the characteristics of the pultruded products obtained in Comparative Examples 1 to 7 are shown in Table 2.

As shown in Tables 1 and 2, the pultruded articles (Examples 1 to 8) containing the components (A) to (E) according to the present invention compared to Comparative Examples 1 to 7 Excellent fast curability and low volumetric shrinkage of the resin. Moreover, the colorability was good and no cracks were observed. Furthermore, the composite with glass fiber and carbon fiber was also good, and the toughness and durability were excellent. In addition, the pot life of the resin was improved by using a microcapsule-type latent curing accelerator (Examples 1 to 4 and Examples 6 to 8) as the component (E).

Claims (6)

Epoxy group-containing vinyl ester resin (A) obtained by reacting ethylenically unsaturated carboxylic acid in an amount of 0.2 to 0.7 equivalents to 1 equivalent of an epoxy group of an epoxy resin having two or more epoxy groups. When,
Styrene, vinyl styrene, chlorostyrene, methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, hexyl (meth) acrylate, decyl (meth) acrylate, lauryl (meth) acrylate, 2-hydroxyethyl (meth) ) Acrylate, 2-hydroxypropyl (meth) acrylate, glycidyl methacrylate, dicyclopentenyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, allyl methacrylate, ethylene glycol di (meth) acrylate, propylene glycol di (meth) ) Acrylate, diethylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, hexanediol di (meth) acrylate, neopen Luglycol di (meth) acrylate, glycerin tri (meth) acrylate, glycerin di (meth) acrylate, trimethylolethane tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolethanedi (meth) acrylate, penta Radical polymerizable monomer selected from erythritol tetra (meth) acrylate, pentaerythritol tri (meth) acrylate and / or allyl glycidyl ether, phenyl glycidyl ether, butyl glycidyl ether, 2-ethylhexyl glycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether Ether, propylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, epoxy diluent selected from resorcinol diglycidyl ether (B), and
An organic peroxide (C);
An epoxy resin curing agent (D) mainly composed of an acid anhydride;
Microcapsule type latent curing accelerator, heat curing type imidazoles, amine adduct type latent curing accelerators, organic acid salts of strong base compounds, onium salts, urea adduct type latent curing accelerators and hydrazide series A latent epoxy resin curing accelerator (E) that is a mixture with at least one selected from latent curing accelerators, and a combination of the radical polymerizable monomer and / or epoxy diluent (B) The amount of the resin composition for pultrusion molding is 10% by mass to 50% by mass with respect to the epoxy group-containing vinyl ester resin (A) .   The epoxy group-containing vinyl ester resin (A) is reacted with 0.4 to 0.7 equivalents of an ethylenically unsaturated carboxylic acid with respect to 1 equivalent of an epoxy group of an epoxy resin having two or more epoxy groups. The resin composition for pultrusion molding according to claim 1, which is obtained. 3. The pultrusion molding according to claim 1, wherein the coating film of the microcapsule-type latent curing accelerator does not dissolve in the radical polymerizable monomer and / or the epoxy diluent (B) at 40 ° C. or lower. Resin composition. A fiber reinforced resin composition comprising the pultrusion resin composition according to any one of claims 1 to 3 and a fiber reinforcing material. A pultrusion method comprising subjecting the fiber-reinforced resin composition according to claim 4 to pultrusion molding under a condition of a pultrusion rate of 30 to 120 cm / min and a temperature of 100 to 200 ° C. A pultruded product formed by the pultrusion method according to claim 5.