JP7243164B2 - VaRTM molding resin composition, molding material, molded article, and method for producing molded article - Google Patents

Description

TECHNICAL FIELD The present invention relates to a resin composition for VaRTM molding, a molding material, a molded article, and a method for producing a molded article.

GFRP (glass fiber reinforced plastic) is a material that can be designed to be lighter, stronger, and more rigid than general structural metal materials, and has excellent water resistance, electrical properties, and corrosion resistance. Conventionally, GFRP has been widely adopted as a material to replace metal materials for large industrial machine parts, sporting goods, and the like.

As a method for molding this GFRP molded product, generally, after releasing the cavity (concave) mold or core (convex) mold made of FRP, it is used as a mold surface, and the unsaturated polyester is manually molded using a defoaming roller. A hand lay-up molding method to obtain a molded product by impregnating glass fiber woven fabric and/or non-woven fabric with a radical curable resin such as resin, vinyl ester resin, and curing at room temperature, or a radical curable resin and glass on the FRP mold surface. Open molding, such as a spray-up molding method, in which a fiber strand is sprayed, impregnated, defoamed, and cured to obtain a molded product, has been used for a long time.
In addition, for the purpose of increasing the productivity and strength of the molded product, the cavity (concave) mold and the core (convex) mold made of metal or FRP whose mold surface has been released from the mold surface in advance are used for the above open mold molding. A fiber reinforcing material is shaped and placed in the part, a radical curable resin composition that can be cured at room temperature or by heating is injected into the cavity in the mold, the fiber reinforcing material is impregnated, and if necessary, after curing by heating the mold. , resin transfer molding (RTM) molding to obtain a molded product by demolding, or using a film instead of a core mold (upper mold) to shape and arrange a fiber reinforcement between the cavity (concave) mold and the film Then, the pressure inside the mold is reduced to draw the radical curable resin into the mold, impregnate the fiber reinforcing material, cure the resin by heating the mold if necessary, and remove the mold to obtain a molded product such as vacuum infusion molding. Closed molding is done.
Furthermore, as a molding method of FRP pursuing productivity, a sheet molding compound is prepared by pre-impregnating a fiber reinforcing material with a resin composition containing a resin, a filler, a curing shrinkage inhibitor, and a curing agent, and thickening the compound into a sheet. (SMC) and bulk molding compound (BMC), which is a lump of compound, are pressed at high temperature and high pressure using a mold to cure, and then removed from the mold to obtain a molded product. Compression (press) molding is performed. there is
As mentioned above, open mold molding is not subject to restrictions on product dimensions and is excellent as a molding method that can be performed with low equipment investment, but it is difficult to improve productivity because most of the molding processes are performed manually. In addition, compression (press) molding, which has excellent productivity, requires a large initial capital investment in large-sized incidental equipment such as molds and presses, and the cost of manufacturing molds is high. In addition to being unsuitable for short products and small-lot production of a wide variety of products, the size of products that can be handled is also restricted by molds and incidental equipment.
Therefore, vacuum-assisted resin transfer molding (VaRTM) is being introduced and transitioned as a molding method that requires less equipment investment than press molding and can improve productivity more than open mold molding. Furthermore, VaRTM molding can select fiber reinforcement and use long fiber fiber reinforcement, and by optimizing the fiber content and its orientation, the strength and elastic modulus can be adjusted according to the shape and application of the product. In recent years, technical development for introduction and mass production has been actively carried out because it has advantages such as being able to design thinner and lighter products in accordance with the requirements of (for example, Patent Document 1).

As mentioned above, VaRTM molding is a molding in which the fiber reinforcement is shaped in advance in the mold, and after the mold is clamped, liquid resin is injected into the mold under reduced pressure, and the fiber reinforcement is impregnated with the matrix resin in the mold and cured. However, in the case of a molded part with a small corner R that is difficult to shape and fill with fiber reinforcement due to its complicated shape, it tends to always be resin-rich, and conventional unsaturated polyester resins and vinyl ester resins are used. When it is used, there is concern about product defects due to cracks occurring in corner portions. In addition, if VaRTM molding is expected to improve productivity from open mold molding such as conventional hand lay-up, it is necessary to set curing conditions for faster curing. Fatal at introduction.

In order to solve this problem, a soft unsaturated polyester resin or vinyl ester resin is added to improve elongation of the cured resin and prevent cracks. It significantly reduces water resistance and heat resistance, making it difficult to apply to molded products that require heat resistance, such as bathroom parts and engine hoods that are required to be used at high temperatures. Therefore, there has been a demand for a resin composition that has excellent moldability and that can provide a molded article having excellent physical properties such as heat resistance and elongation of the cured resin.

WO2018/105380

The problem to be solved by the present invention is to provide a VaRTM molding resin composition, a molding material, a molded article, and a method for producing a molded article that can obtain molded articles that are excellent in moldability and various physical properties such as heat resistance and elongation. It is to be.

The present inventors have found that a VaRTM molding resin composition containing a specific epoxy (meth)acrylate and styrene is excellent in moldability and can give molded articles excellent in various physical properties such as heat resistance and elongation. We have completed the present invention.

That is, a resin composition for VaRTM molding containing epoxy (meth)acrylate (A) and styrene (B), wherein the epoxy equivalent of the epoxy resin, which is the raw material of the epoxy (meth)acrylate (A), is 250 to 500. and the mass ratio (A/B) of the epoxy (meth)acrylate (A) and the styrene (B) is in the range of 60/40 to 45/55. Regarding the composition.

Molded articles obtained from the VaRTM molding resin composition of the present invention are excellent in heat resistance and elongation in addition to general properties such as appearance, strength, and elastic modulus. It can be suitably used for members, ship members, housing equipment members, sports members, vehicle members, construction and civil engineering members, housings of OA equipment, and the like.

The VaRTM molding resin composition of the present invention is a VaRTM molding resin composition containing epoxy (meth)acrylate (A) and styrene (B), and is a raw material of the epoxy (meth)acrylate (A). The epoxy equivalent of the epoxy resin is in the range of 250 to 500, and the mass ratio (A/B) of the epoxy (meth)acrylate (A) and the styrene (B) is in the range of 60/40 to 45/55. It is.

In the present invention, "(meth)acrylate" refers to one or both of acrylate and methacrylate, and "(meth)acrylic acid" refers to one or both of acrylic acid and methacrylic acid.

The epoxy (meth)acrylate can be obtained by reacting an epoxy resin with (meth)acrylic acid. It becomes an epoxy (meth)acrylate with a high cross-linking density, and a cured product with high heat resistance can be obtained by copolymerization with a reactive monomer such as styrene. Conversely, if (meth)acrylic acid is reacted with both ends of an epoxy with a large epoxy equivalent, it becomes an epoxy (meth)acrylate with a low intercrosslink distance, i.e., a low crosslink density, and excellent elongation when copolymerized with a reactive monomer such as styrene. A cured product is obtained. In this way, the heat resistance and elongation of the cured resin obtained by copolymerizing epoxy (meth)acrylate and a reactive monomer such as styrene tend to contradict each other. Therefore, it is important that the epoxy equivalent of the epoxy resin is in the range of 250-500, preferably in the range of 280-450, and more preferably in the range of 300-400.

Examples of the epoxy resin include bisphenol A-type epoxy resins, bisphenol F-type epoxy resins, bisphenol fluorene-type epoxy resins, bisphenol-type epoxy resins such as bis-cresol fluorene-type epoxy resins, phenol novolac-type epoxy resins, cresol novolac-type epoxy resins, and the like. Phenol glycidyl ether, dipropylene glycol diglycidyl ether, trimethylolpropane triglycidyl ether, diglycidyl ether of alkylene oxide adduct of bisphenol A, such as novolac type epoxy resin, oxodoridone modified epoxy resin, brominated epoxy resin of these resins , glycidyl ethers of polyhydric alcohols such as diglycidyl ether of hydrogenated bisphenol A, 3,4-epoxy-6-methylcyclohexylmethyl-3,4-epoxy-6-methylcyclohexanecarboxylate, 1-epoxyethyl-3,4 - Alicyclic epoxy resins such as epoxycyclohexane, diglycidyl phthalate, diglycidyl tetrahydrophthalate, diglycidyl-p-oxybenzoic acid, glycidyl esters such as dimer acid glycidyl ester, tetraglycidyldiaminodiphenylmethane, tetraglycidyl-m -glycidylamines such as xylenediamine, triglycidyl-p-aminophenol, N,N-diglycidylaniline, 1,3-diglycidyl-5,5-dimethylhydantoin, heterocyclic epoxy resins such as triglycidyl isocyanurate, etc. mentioned. Among these, bifunctional aromatic epoxy resins are preferred because they are superior in molded product strength, handling properties of molding materials, and fluidity of molding materials during molding, and bisphenol A type epoxy resins and bisphenol F type epoxy resins are more preferable. preferable. These epoxy resins can be used alone or in combination of two or more.

The reaction between the epoxy resin and (meth)acrylic acid is preferably carried out at 60 to 140° C. using an esterification catalyst. A polymerization inhibitor or the like can also be used.

The mass ratio (A/B) of the epoxy (meth)acrylate (A) and styrene (B) is 40/60 to 55/40/60 to 55/60 to achieve both moldability and excellent heat resistance and elongation of the resulting molded product. A range of 45 is important and a range of 45/55 to 55/45 is preferred.

An unsaturated monomer other than styrene may be used in the resin composition of the present invention. Examples of the unsaturated monomer include methyl methacrylate, benzyl (meth) acrylate, phenoxyethyl (meth) acrylate, phenoxy polyethylene glycol (meth) acrylate, polyethylene glycol (meth) acrylate alkyl ether, polypropylene glycol (meth) Acrylate alkyl ether, 2-ethylhexyl methacrylate, isodecyl (meth) acrylate, lauryl (meth) acrylate, isotridecyl (meth) acrylate, n-stearyl (meth) acrylate, tetrahydrofurfuryl methacrylate, isobornyl (meth) acrylate, dicyclopentenyloxy monofunctional (meth)acrylate compounds such as ethyl (meth)acrylate and dicyclopentanyl methacrylate; ethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1 , 3-butanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, bisphenol di(meth)acrylate, 1,4-cyclohexanedimethanol di(meth) Di(meth)acrylate compounds such as acrylates; diallyl phthalate, divinylbenzene, etc.; Methacrylate and phenoxyethyl methacrylate are more preferred. These unsaturated monomers may be used alone or in combination of two or more.

As the resin component of the VaRTM molding resin composition of the present invention, a component other than the epoxy (meth)acrylate (A) and styrene (B) may be used, for example, the epoxy (meth)acrylate (A) Thermosetting resins, thermoplastic resins, polymerization inhibitors, etc. other than the above can be contained.

Examples of the thermosetting resin include unsaturated polyester resins, vinyl ester resins, acrylic resins, epoxy resins, phenol resins, melamine resins, and furan resins. Moreover, these thermosetting resins can be used alone or in combination of two or more.

Examples of the thermoplastic resin include polyamide resin, polyethylene terephthalate resin, polybutylene terephthalate resin, polycarbonate resin, urethane resin, polypropylene resin, polyethylene resin, polystyrene resin, acrylic resin, polybutadiene resin, polyisoprene resin, and copolymers thereof. and the like. Moreover, these thermoplastic resins can be used alone or in combination of two or more.

Examples of the polymerization inhibitor include hydroquinone, trimethylhydroquinone, pt-butylcatechol, t-butylhydroquinone, trihydroquinone, p-benzoquinone, naphthoquinone, hydroquinone monomethyl ether, phenothiazine, copper naphthenate, copper chloride, and the like. be done. These polymerization inhibitors can be used alone or in combination of two or more.

The resin composition for VaRTM molding of the present invention is obtained by mixing the epoxy (meth)acrylate (A), styrene (B) and, if necessary, other components.

The viscosity of the VaRTM molding resin composition of the present invention is preferably in the range of 50 to 300 mPa s at 25 ° C., and 70 to 200 mPa, because the injection time into the mold and the impregnation of the fiber are further improved. • A range of s is more preferred.

The molding material of the present invention contains the VaRTM molding resin composition, a polymerization initiator (C), and a fiber reinforcing material (D).

The polymerization initiator (C) is not particularly limited, but is preferably an organic peroxide. Examples include diacyl peroxide compounds, peroxyester compounds, hydroperoxide compounds, ketone peroxide compounds, alkyl perester compounds, Carbonate compounds, peroxyketals and the like can be mentioned, and can be appropriately selected according to the molding conditions. These polymerization initiators (C) can be used alone or in combination of two or more.

Among these, it is preferable to use a polymerization initiator having a temperature of 70° C. or more and 110° C. or less for obtaining a 10-hour half-life. If the temperature is 70° C. or higher and 110° C. or lower, the fiber-reinforced molding material has a long life at room temperature, and can be cured in a short time by heating. Examples of such polymerization initiators include 1,6-bis(t-butylperoxycarbonyloxy)hexane, 1,1-bis(t-butylperoxy)cyclohexane, 1,1-bis(t- amylperoxy)cyclohexane, 1,1-bis(t-hexylperoxy)cyclohexane, t-butylperoxy-2-ethylhexanoate, t-butylperoxydiethyl acetate, t-butylperoxyisopropyl carbonate, t -amylperoxyisopropyl carbonate, t-hexylperoxyisopropylcarbonate, di-t-butylperoxyhexahydroterephthalate, t-amylperoxytrimethylhexanoate, t-amylperoxy-2-ethylhexanoate, t -butyl peroxy-3,5,5-trimethylhexanoate, t-butyl peroxy-benzoate, di-(4-t-butylcyclohexyl)-peroxydicarbonate, methyl ethyl ketone peroxide, acetylacetone peroxide, cumene hydro peroxide, benzoyl peroxide and the like.

The content of the polymerization initiator (C) is from 0.3 to 0.3 based on the total amount of the epoxy (meth)acrylate (A) and styrene (B), since both curing properties and storage stability are excellent. A range of 3% by weight is preferred.

Examples of the fiber reinforcing material (D) include organic fibers such as carbon fiber, glass fiber, silicon carbide fiber, alumina fiber, boron fiber, metal fiber, aramid fiber, vinylon fiber, polyester fiber, polypropylene fiber, and polyethylene fiber. However, carbon fiber or glass fiber is preferable because a molded product with higher strength and higher elasticity can be obtained. These fiber reinforcing materials (D) can be used alone or in combination of two or more.

As the glass fiber, for example, those obtained by using alkali-containing glass, low-alkali glass, alkali-free glass, etc. as raw materials can be used. Glass (E-glass) is preferably used.

As the carbon fiber, various types such as polyacrylonitrile, pitch, and rayon can be used. Among these, polyacrylonitrile is preferable because high strength carbon fiber can be easily obtained.

As the form of the fiber reinforcing material (D), a unidirectional woven fabric in which the fibers are aligned in almost the same direction and integrated with an auxiliary weft or a binder, or a bidirectional woven fabric in which at least carbon fibers are interlaced in two directions. , multiaxial fabrics interlaced in multiple directions, multiaxial stitching base materials in which sheets with carbon fibers aligned in one direction are laminated in multiple directions and integrated with stitching threads, braided cords, and discontinuous fibers are also used. It may be used as a nonwoven fabric or a mat, or as a preform that is laminated, shaped, and fixed in shape by means of a binder, stitching, or the like.

The content of the fiber reinforcing material (D) in the molding material of the present invention is preferably in the range of 10 to 70% by volume, more preferably 15 to 60% by volume, because the mechanical properties of the resulting molded product are further improved. is more preferred.

As the molding material of the present invention, materials other than the VaRTM molding resin composition, the polymerization initiator (C), and the fiber reinforcing material (D) may be used. , low shrinkage agents, release agents, thickeners, viscosity reducers, pigments, antioxidants, plasticizers, flame retardants, antibacterial agents, UV stabilizers, reinforcing agents, photocuring agents, and the like.

Examples of the polymerization inhibitor include hydroquinone, trimethylhydroquinone, pt-butylcatechol, t-butylhydroquinone, trihydroquinone, p-benzoquinone, naphthoquinone, hydroquinone monomethyl ether, phenothiazine, copper naphthenate, copper chloride, and the like. be done. These polymerization inhibitors can be used alone or in combination of two or more.

Examples of the curing accelerator include metallic soaps such as cobalt naphthenate, cobalt 2-ethylhexanoate, vanadyl 2-ethylhexanoate, copper naphthenate, and barium naphthenate; vanadyl acetyl acetate; cobalt acetyl acetate; Metal chelate compounds such as acetonate are included. As amine compounds, N,N-dimethylamino-p-benzaldehyde, N,N-dimethylaniline, N,N-diethylaniline, N,N-dimethyl-p-toluidine, N-ethyl-m-toluidine, triethanol amine, m-toluidine, diethylenetriamine, pyridine, phenylmorpholine, piperidine, diethanolaniline and the like. These curing accelerators can be used alone or in combination of two or more.

Examples of the filler include inorganic compounds and organic compounds, which can be used to adjust physical properties such as strength, elastic modulus, impact strength, and fatigue durability of molded articles. These fillers can be used alone or in combination of two or more.

Examples of the inorganic compound include calcium carbonate, magnesium carbonate, barium sulfate, mica, talc, kaolin, clay, celite, asbestos, barite, baryta, silica, silica sand, dolomite limestone, gypsum, aluminum fine powder, hollow balloons, Alumina, glass powder, aluminum hydroxide, cold water stone, zirconium oxide, antimony trioxide, titanium oxide, molybdenum dioxide, iron powder and the like.

Examples of the organic compound include powders of natural polysaccharides such as cellulose and chitin, powders of synthetic resins, and the like, and powders of synthetic resins include hard resins, soft rubbers, elastomers, polymers (copolymers), and the like. Particles having a multi-layered structure such as organic powders and core-shell type particles can be used. Specific examples include particles of butadiene rubber and/or acrylic rubber, urethane rubber, silicon rubber, polyimide resin powder, fluororesin powder, phenol resin powder, and the like.

Examples of the release agent include zinc stearate, calcium stearate, paraffin wax, polyethylene wax, carnauba wax and the like. Paraffin wax, polyethylene wax, carnauba wax and the like are preferred. These release agents can be used alone or in combination of two or more.

The molding material of the present invention is obtained by mixing the VaRTM molding resin composition, the polymerization initiator (C), the fiber reinforcing material (D), and, if necessary, other components.

The molded article of the present invention can be obtained by a known VaRTM molding method. With the mold temperature adjusted to 60° C., the VaRTM molding resin composition is press-fitted at 100 kPa to 12 MPa if necessary, impregnated into the fiber reinforcing material (D), and also post-cured, and the mold temperature is 80 to 140. C., hardened for 5 to 60 minutes, and demolded.

The content of the fiber reinforcing material (D) in the molded article of the present invention is preferably in the range of 10 to 70% by volume, and 15 to 60% by volume, because the mechanical properties of the resulting molded article are further improved. A range is more preferred. If the fiber reinforcement content is low, a high-strength molded product may not be obtained. There is also a possibility that a high-strength molded product cannot be obtained.

Molded articles obtained using the VaRTM molding resin composition of the present invention can express heat resistance and elongation in a good balance, so they are It can be used for sports members, light vehicle members, construction and civil engineering members, housings of OA equipment, and the like. In addition, since the resin composition of the present invention can achieve both heat resistance and elongation with low viscosity, it is a molded article having a corner R shape that is particularly complicated in shape and difficult to shape and fill with a fiber reinforcing material such as glass fiber. In addition to application to shapes, it can also be suitably used to prevent cracks in corner portions that tend to become resin-rich portions.

The present invention will be described in more detail below with specific examples.

(Synthesis Example 1: Synthesis of epoxy methacrylate (A-1))
A 2 L flask equipped with a thermometer, a nitrogen inlet tube, and a stirrer was charged with 754 parts by mass of epoxy resin ("Epiclon 850" manufactured by DIC Corporation, bisphenol A type epoxy resin, epoxy equivalent of 188) and 181 parts by mass of bisphenol A. was heated to 110° C. with stirring. 0.40 part by mass of 2-methylimidazole was added thereto, and the reaction was carried out at 110° C. until the epoxy equivalent of the reactant reached 380. Next, 202 parts by mass of methacrylic acid and 0.40 parts by mass of hydroquinone were charged, and the temperature was raised to 90° C. under a gas flow of a 1:1 mixture of nitrogen and air. 1.00 parts by mass of 2-methylimidazole was added thereto, and the temperature was raised to 105° C. to continue the reaction until the acid value was 9 or less. After cooling to around 60° C., it was taken out from the reaction vessel to obtain epoxy methacrylate (A-1).

(Synthesis Example 2: Synthesis of epoxy methacrylate (A-2))
856 parts by mass of epoxy resin ("Epiclon 850" manufactured by DIC Corporation, bisphenol A type epoxy resin, epoxy equivalent 188) and 140 parts by mass of bisphenol A were charged into a 2 L flask equipped with a thermometer, a nitrogen inlet tube, and a stirrer. was heated to 110° C. with stirring. 0.40 part by mass of 2-methylimidazole was added thereto, and the reaction was carried out at 110° C. until the epoxy equivalent of the reactant reached 310. Next, 272 parts by mass of methacrylic acid and 0.40 parts by mass of hydroquinone were charged, and the temperature was raised to 90° C. under a gas flow of a 1:1 mixture of nitrogen and air. 1.00 parts by mass of 2-methylimidazole was added thereto, and the temperature was raised to 105° C. to continue the reaction until the acid value was 10 or less. After cooling to around 60° C., it was taken out from the reaction vessel to obtain epoxy methacrylate (A-2).

(Synthesis Example 3: Synthesis of epoxy methacrylate (A-3))
805 parts by mass of epoxy resin ("Epiclon 850" manufactured by DIC Corporation, bisphenol A type epoxy resin, epoxy equivalent 188) and 207 parts by mass of bisphenol A were charged into a 2 L flask equipped with a thermometer, a nitrogen inlet tube, and a stirrer. was heated to 110° C. with stirring. 0.40 part by mass of 2-methylimidazole was added thereto, and the reaction was carried out at 110° C. until the epoxy equivalent of the reactant reached 420. Next, 197 parts by mass of methacrylic acid and 0.40 parts by mass of hydroquinone were charged, and the temperature was raised to 90° C. under a gas flow of a 1:1 mixture of nitrogen and air. 1.00 parts by mass of 2-methylimidazole was added thereto, and the temperature was raised to 105° C. to continue the reaction until the acid value was 7 or less. After cooling to around 60° C., it was taken out from the reaction vessel to obtain epoxy methacrylate (A-3).

(Example 1: Preparation and evaluation of VaRTM molding resin composition (1))
0.008 parts by mass of hydroquinone was added to 100 parts by mass of a resin solution obtained by dissolving 48 parts by mass of the epoxy methacrylate (A-1) obtained in Synthesis Example 1 in 52 parts by mass of styrene to obtain VaRTM molding resin composition (1). got The VaRTM molding resin composition (1) had a viscosity of 80 mPa·s at 25°C.

[Production of molded product X (1)]
Per 100 parts by mass of the VaRTM molding resin composition (1), 0.2 parts by mass of 6% cobalt octylate as a curing accelerator ("Accelerator RP-330" manufactured by DIC Materials Co., Ltd.), a polymerization initiator ( Kayaku Akzo Co., Ltd. "Trigonox 40", acetylacetone peroxide) 1.0 parts by mass was evenly blended, vacuum defoaming was performed, and then the upper edge was covered with two glass plates whose inner surfaces were release-treated. The void formed by sealing the other parts with a 3 mm thick silicone rubber packing was cast as a mold, cured at room temperature for 24 hours, and then after-cured in a dryer at 120 ° C. for 2 hours. ).

[Evaluation of heat resistance (deflection temperature under load)]
Regarding the molded product X(1) obtained above, the heat resistance was evaluated by measuring the deflection temperature under load according to JIS K7191-1. The higher the deflection temperature under load, the better the heat resistance.

[Evaluation of tensile strength and tensile elongation]
For the molded product X(1) obtained above, a tensile test was performed on the 1B test piece according to JIS K7161-1 and 2 to measure the tensile strength and elongation.

[Preparation of Molded Product Y (1)]
On the mold surface (400 mm × 400 mm), glass fiber reinforcement (manufactured by Nittobo Co., Ltd., "WF350 100 BS6R", plain weave cloth, 330 g / m ² ) 250 mm × 250 mm: 7 plies, resin supply line, φ 6 mm spiral as decompression line Place the tube, peel ply ("BleederLeaseB" manufactured by AIRTECH), flow media ("Greenflow75" manufactured by AIRTECH), bagging film ("KM1300" manufactured by AIRTECH) in this order, cover the bagging film peripheral edge and mold surface and , the resin supply, and the vacuum hose were sealed with a sealing tape ("AT-200Y" manufactured by AIRTECH). The length of the resin supply hose reached the bottom of the resin tank. Also, the decompression hose was connected to a vacuum pump via a decompression gauge.
The resin supply hose in front of the resin tank was cut off with a vise plier, the vacuum pump was operated, the airtightness between the mold and the bagging film was confirmed, and the pressure was maintained at 10 kPa or less with a vacuum gauge.
300 parts by mass of VaRTM molding resin composition (1) and 6% cobalt octylate as a curing accelerator ("Accelerator RP-330" manufactured by DIC Materials Co., Ltd.) are placed in the resin tank while maintaining the degree of pressure reduction. 0.6 part by mass and 3.0 parts by mass of a polymerization initiator ("Trigonox 40", acetylacetone peroxide manufactured by Kayaku Akzo Co., Ltd.) were evenly blended, degassed under vacuum, and then transferred.
The vise pliers on the resin supply hose were released to begin injecting resin into the glass fiber reinforcement between the mold and film. Injection to the entire surface of the glass fiber reinforcing material was completed in about 5 minutes, and the resin supply hose and decompression hose were cut off with vise pliers. After gelling at normal temperature as it was, it was post-cured at 60° C. for 1 hour to obtain molded article Y(1). The resulting molded product Y(1) had a plate thickness of 2.0 mm and a glass fiber content of 49.6% by volume.

[Evaluation of formability (appearance)]
The appearance of the molded product Y(1) obtained above was visually evaluated according to the following criteria.
○: No non-impregnated part ×: Not impregnated

(Example 2: Preparation and evaluation of VaRTM molding resin composition (2))
0.008 parts by mass of hydroquinone was added to 100 parts by mass of a resin solution obtained by dissolving 50 parts by mass of the epoxy methacrylate (A-2) obtained in Synthesis Example 2 in 50 parts by mass of styrene to obtain VaRTM molding resin composition (2). got The VaRTM molding resin composition (2) had a viscosity of 60 mPa·s at 25°C.

Molded article X (2) and molded article Y (2) was produced and each evaluation was performed.

(Comparative Example 1: Preparation and evaluation of VaRTM molding resin composition (R1))
0.008 parts by mass of hydroquinone was added to 100 parts by mass of a resin solution obtained by dissolving 65 parts by mass of the epoxy methacrylate (A-2) obtained in Synthesis Example 2 in 35 parts by mass of styrene to obtain a resin composition for VaRTM molding (R1). got The viscosity of this VARTM molding resin composition (R1) was 500 mPa·s at 25°C.

Molded article X (R1) and molded article Y (R1) was produced and each evaluation was performed.

(Comparative Example 2: Preparation and evaluation of VaRTM molding resin composition (R2))
0.008 parts by mass of hydroquinone was added to 100 parts by mass of a resin solution obtained by dissolving 40 parts by mass of the epoxy methacrylate (A-3) obtained in Synthesis Example 3 in 60 parts by mass of styrene to obtain a VaRTM molding resin composition (R2). got The VaRTM molding resin composition (R2) had a viscosity of 40 mPa·s at 25°C.

Molded article X (R2) and molded article Y (R2) was produced and each evaluation was performed.

Table 1 shows the evaluation results of VaRTM molding resin compositions (1), (2), (R1) and (R2) obtained above.

It was confirmed that the resin compositions for VaRTM molding of the present invention of Examples 1 and 2 are excellent in moldability, and the obtained molded articles are excellent in tensile strength, elongation and heat resistance.

On the other hand, Comparative Example 1 is an example in which the amount of styrene in the composition is small and the mass ratio (A/B) is outside the range of the present invention, but the moldability and tensile strength of the molded product are insufficient. was confirmed.

Comparative Example 2 is an example in which the amount of styrene in the composition is large and the mass ratio (A/B) is outside the range of the present invention, but the tensile strength and deflection temperature under load of the molded product are insufficient. was confirmed.

Claims (3)

A resin composition for VaRTM molding containing epoxy (meth)acrylate (A) and styrene (B), wherein the epoxy equivalent of the epoxy resin that is the raw material of the epoxy (meth)acrylate (A) is in the range of 250 to 450. and the mass ratio (A/B) of the epoxy (meth)acrylate (A) and the styrene (B) is in the range of 60/40 to 45/55, and the viscosity at 25° C. is 50 to 300 mPa s VaRTM molding resin composition characterized in that it is in the range of . A molding material comprising the VaRTM molding resin composition according to claim 1 , a polymerization initiator (C), and a fiber reinforcing material (D). A molded article, which is a cured product of the molding material according to claim 2 .