JP4634781B2 - Prepreg for fiber reinforced resin composite material - Google Patents

Description

  The present invention relates to a prepreg for a fiber-reinforced composite material. More specifically, the present invention can produce a fiber reinforced resin composite material having a unique depth and gloss in a short time, and further impart high heat resistance and toughness to the fiber reinforced resin composite material by post-heating. The present invention relates to a prepreg for a fiber-reinforced composite material.

  A fiber-reinforced resin composite material reinforced with reinforcing fibers such as carbon fibers and glass fibers generally has a feature of being excellent in specific strength, specific rigidity, and the like. Further, such fiber reinforced resin composite materials are widely used in various applications ranging from structural materials for aircraft to sports applications such as automotive parts, rackets and golf shafts, taking advantage of their light weight. Yes. On the other hand, these fiber reinforced resin composite materials have unique luster and depth of design characteristics, and also have a beautiful appearance even in a single form, so interior parts such as automotive instrument panels and shift knobs, bonnets and In addition to automotive exterior parts such as wings and bumpers, they are also used as design materials such as exterior parts for motorcycles and surface materials for furniture such as chairs.

  As a molding method of this fiber reinforced resin composite material, there is a method of curing and molding by autoclave molding, vacuum back molding, press molding using an intermediate material called prepreg in which a reinforcing fiber is impregnated with a thermosetting resin. It is common.

  The resin for prepreg usually needs to be a resin having both stability at room temperature and curability due to heating, etc., and thus generally includes epoxy resin compositions and (meth) acrylic resins. Thermosetting resins are frequently used. The use of (meth) acrylic resin, which has excellent transparency after resin curing, is preferred for design because the gloss and depth of the fiber reinforced resin composite material stands out and the geometric pattern of the reinforced fiber looks more vivid. Often used.

  However, the curing of the thermosetting resin requires heating for a certain period of time or curing at room temperature, and if the temperature rising time to a predetermined temperature or the time for cooling to a temperature at which the molded body can be taken out is included, the resin The time required for curing or polymerizing the resin becomes longer, and there is a limit to reducing the cost by improving the production cycle. On the other hand, a resin having good curability at room temperature is hardened at room temperature, and cannot be established and stable as a prepreg.

  In the field of coating materials used for DVD (Digital Versatile Disc) media, automotive headlamps, etc., radical ultraviolet curable resins are often used. This is because the resin can be cured only by irradiating with ultraviolet rays, so that the resin can be molded in a much shorter time than heat curing, and the productivity can be remarkably improved.

  Attempts have been made to shorten the molding time of the fiber-reinforced resin composite material by using the radical ultraviolet curable resin composition that can be molded in a short time as a matrix resin for prepreg. However, if reinforcing fibers are present in such a matrix resin, the ultraviolet rays are blocked by the reinforcing fibers, the internal matrix resin is insufficiently cured, and even if the surface is cured, the internal uncured resin is stained on the surface. Problems such as coming out will occur.

  In JP-A-3-146528 (Patent Document 1), an acryloyl compound containing a photo radical initiator and a thermal radical initiator is used as a matrix resin, glass fibers are used as reinforcing fibers, and the matrix resin is thickened by ultraviolet irradiation. A technique for forming a glass-reinforced fiber resin composite material using an acrylic resin as a matrix resin by producing a staged prepreg and heat-curing the B-staged prepreg is shown. However, although this technique uses glass fibers that are relatively easy to transmit ultraviolet rays, the matrix resin can be thickened by ultraviolet irradiation to form a B-stage. It is not enough to mold the material.

  On the other hand, not only the design properties such as gloss and depth of the fiber reinforced resin composite material with such a transparent resin, but also withstand severe environments in applications such as motorcycles and automobile exterior parts. The matrix resin is often required to have excellent toughness and heat resistance.

Japanese Patent Laid-Open No. 3-146528

  An object of the present invention is to provide a prepreg for a radical curable fiber-reinforced resin composite material that has excellent design properties and can realize high productivity and excellent toughness and heat resistance by post-curing.

（Ｒ¹は水素もしくはメチル基である）
（ｂ）ビスフェノールＡジグリシジルエーテルの（メタ）アクリル酸付加物２０−５０質量部
（ｃ）化学式IIで示されるジ（メタ）アクリレート化合物１０−３５質量部

（Ｒ¹は水素もしくはメチル基、Ｒ³は炭素数３〜６の直鎖型炭化水素基、Ｒ⁴は炭素数２〜１５の分岐、環状、または直鎖型炭化水素基、または芳香環を有する炭化水素基であって、該構造中にエステル構造を含んでいても良い）
を必須成分として含むラジカル重合性樹脂１００質量部と、
（ｄ）α−アミノアルキルフェノン型光重合開始剤及びチオキサントン型光重合開始剤を合わせて０．０５−１０質量部、および、
（ｅ）熱重合開始剤０．０５−１０質量部を含むラジカル重合性樹脂組成物である。 According to the present invention, there is provided a prepreg for a fiber reinforced resin composite material including at least a reinforced fiber and a radical polymerizable resin composition. The radical polymerizable resin composition includes the following components (a), (b), and (c):
(A) 30-50 parts by mass of a tri (meth) acrylate compound represented by Formula I

(R ¹ is hydrogen or methyl group)
(B) 20-50 parts by mass of (meth) acrylic acid adduct of bisphenol A diglycidyl ether (c) 10-35 parts by mass of di (meth) acrylate compound represented by chemical formula II

(R ¹ is hydrogen or a methyl group, R ³ is a straight chain hydrocarbon group having 3 to 6 carbon atoms, R ⁴ is a branched, cyclic, or straight chain hydrocarbon group having 2 to 15 carbon atoms, or an aromatic ring. A hydrocarbon group having an ester structure in the structure)
100 parts by mass of a radically polymerizable resin containing as an essential component,
(D) 0.05-10 parts by mass of the α-aminoalkylphenone type photopolymerization initiator and the thioxanthone type photopolymerization initiator in combination, and
(E) A radical polymerizable resin composition containing 0.05 to 10 parts by mass of a thermal polymerization initiator.

  As the thermal polymerization initiator (e) described above, it is preferable to use a thermal polymerization initiator having a temperature for obtaining a half-life of 10 hours of 40 ° C. or higher and 130 ° C. or lower. As the above-mentioned reinforcing fiber, it is more preferable to use a carbon fiber to which a sizing agent having a compound having at least one (meth) acrylate group and epoxy group in the molecule is attached.

  According to the present invention configured as described above, it is possible to mold a fiber-reinforced resin composite material having a design property in a very short time by irradiation with ultraviolet rays, and for applications where heat resistance and toughness are required. , (For example, at a temperature of about 150 ° C.), a molded body having excellent heat resistance and toughness can be obtained.

  Hereinafter, the present invention will be described more specifically with reference to the drawings as necessary. In the following description, “parts” and “%” representing the quantity ratio are based on mass (weight) unless otherwise specified.

(Prepreg for fiber reinforced resin composite material)
The prepreg for fiber-reinforced resin composite material of the present invention includes at least reinforcing fibers and a radical polymerizable resin composition.

(Radical polymerizable resin composition)
In the present invention, the radical polymerizable resin composition includes the following components (a), (b), and (c), and in addition to the following components (d) and (e).

((A) component)
The essential component (a) of the radical polymerizable resin used in the present invention is a tri (meth) acrylate compound represented by the chemical formula I. This essential component (a) needs to be contained in an amount of 30 to 50 parts by mass with respect to 100 parts by mass of the radical polymerizable resin in which the components (a), (b) and (c) are contained as essential components. If the blending amount of component (a) is 30 parts by mass or more, the heat resistance of the resulting radically polymerizable resin is increased, and if the blending amount is 50 parts by mass or less, the toughness of the resulting radically polymerizable resin. This is because of the increase. Furthermore, the compounding quantity of a preferable component (a) is 35-45 mass parts. Examples of the triacrylate compound represented by the chemical formula I include, but are not limited to, Aronix M-315 (Toagosei), Kayarad R-790 (Nippon Kayaku) and the like as commercial products.

（Ｒ¹は水素もしくはメチル基である）

(R ¹ is hydrogen or methyl group)

(Component (b))
The essential component (b) of the radical polymerizable resin used in the present invention is a (meth) acrylic acid adduct of bisphenol A diglycidyl ether. The essential component (b) needs to be contained in an amount of 20 to 50 parts by mass with respect to 100 parts by mass of the radical polymerizable resin in which the components (a), (b) and (c) are contained as essential components. If the blending amount of component (b) is 20 parts by mass or more, the toughness of the obtained radical polymerizable resin is increased, and if it is 50 parts by mass or less, the heat resistance of the obtained radical polymerizable resin is increased. . Furthermore, the compounding quantity of a preferable component (b) is 25-40 mass parts. As a (meth) acrylic acid adduct of bisphenol A diglycidyl ether, commercially available products include epoxy ester 3000A (Kyoeisha Chemical), epoxy ester 3000M (Kyoeisha Chemical), lipoxy SP1509 (Showa High Polymer), and lipoxy VR77 (Showa High Polymer). ), Lipoxy SP1507 (Showa Polymer) and the like, but are not limited thereto.

(Component (c))
In the present invention, the essential component (c) of the radical polymerizable resin is a di (meth) acrylate compound represented by the chemical formula II. The essential component (c) needs to be contained in an amount of 10 to 35 parts by mass with respect to 100 parts by mass of the radical polymerizable resin in which the components (a), (b) and (c) are contained as essential components. If the compounding amount of component (c) is 10 parts by mass or more, the toughness of the obtained radical polymerizable resin is increased, and if it is 35 parts by mass or less, the heat resistance of the obtained radical polymerizable resin is increased. Furthermore, the compounding quantity of a preferable component (c) is 20-35 mass parts. Specific examples of the di (meth) acrylate compound represented by Chemical Formula II include addition of 2 to 10 mol of γ-butyrolactone or ε-caprolactone to 1 mol of an aliphatic, alicyclic, or aromatic skeleton dialcohol. And compounds obtained by methacrylate or acrylate conversion of the dialcohol terminal. Among these, di (meth) acrylic acid ester of neon pentyl glycol hydroxypivalate (m + n = 2 to 5), γ-butyrolactone adduct of neon pentyl glycol hydroxypivalate (m + n = 2-5) di (meth) acrylic acid ester, neon pentyl glycol caprolactone adduct (m + n = 2 to 5) di (meth) acrylic acid ester, butylene glycol caprolactone adduct (m + n = 2 to 5) Di (meth) acrylic acid ester, di (meth) acrylic acid ester of caprolactone adduct of cyclohexanedimethanol (m + n = 2 to 5), di (meth) of caprolactone adduct of cyclopentanediol (m + n = 2 to 5) Acrylic acid ester, bisphenol A Di (meth) acrylic acid ester of caprolactone adduct (m + n = 2 to 5), and di (meth) acrylic acid ester of caprolactone adduct (m + n = 2 to 5) of bisphenol F.

（Ｒ¹は水素もしくはメチル基、Ｒ³は炭素数３〜６の直鎖型炭化水素基、Ｒ⁴は炭素数２〜１５の分岐、環状、または直鎖型炭化水素基、または芳香環を有する炭化水素基であって、該構造中にエステル構造を含んでいても良い）

(R ¹ is hydrogen or a methyl group, R ³ is a straight chain hydrocarbon group having 3 to 6 carbon atoms, R ⁴ is a branched, cyclic, or straight chain hydrocarbon group having 2 to 15 carbon atoms, or an aromatic ring. A hydrocarbon group having an ester structure in the structure)

(Other radical polymerizable resins)
In the present invention, the above-mentioned radical polymerizable resin may contain other radical polymerizable resins as necessary in addition to the essential components (a), (b) and (c). Various vinyl monomers and vinyl oligomers such as vinyl ester resins and unsaturated polyester resins can be included. In this invention, the compounding quantity of such "other radically polymerizable resin" is 30 mass parts or less with respect to 100 mass parts of total amounts of above-mentioned essential (a), (b) and (c) components. (Furthermore, it is preferably 10 parts by mass or less).

(Components other than radical polymerizable resin)
The above-mentioned radical polymerizable resin has various physical properties such as heat resistance, toughness, rigidity, flame retardancy, surface smoothness, strain reduction, mold release property, color tone, etc. in the uncured state. Components other than the radical polymerizable resin may be included as necessary for the purpose of adjusting handling properties such as adhesiveness and viscosity. Examples of such “components other than radically polymerizable resins” include thermosetting resins, thermoplastic resins, elastomers, inorganic fillers, and the like. Examples of such thermosetting resins include crosslinkable resins such as epoxy resins, triazine resins, bismaleimide resins, cyanate ester resins, and curing agents thereof. Examples of the thermoplastic resin include polysulfone, polyethersulfone, polyimide, polyetherimide, polyvinyl formal, polyamide, phenoxy resin, polyurethane, polystyrene, polyethylene, polyacrylate, polysiloxane, and the like. Examples of the elastomer component include butadiene rubber, acrylic rubber, styrene rubber, chloroprene rubber, styrene-butadiene rubber, butadiene-acrylonitrile rubber, carboxy-terminal-modified butadiene-acrylonitrile rubber, isoprene rubber, butadiene rubber, and the like. Inorganic fillers include metal hydroxides such as aluminum hydroxide and magnesium hydroxide, participating metals such as magnesium oxide and aluminum oxide, metal carbonates such as calcium carbonate, aluminum carbonate and magnesium carbonate, glass balloons, An inorganic filler such as silica can be used. Furthermore, additives such as a defoaming agent, a wetting agent, and a leveling agent can be blended as necessary.

(Component (d))
The component (d) in the invention is a photopolymerization initiator that generates radicals by irradiation with ultraviolet rays. By including both components of the α-aminoalkylphenone type photopolymerization initiator and the thioxanthone type photopolymerization initiator as this component (d), the UV curable property of the matrix resin in the presence of the reinforcing fibers becomes good. Of these two components, only one of these components will not cure sufficiently even if the prepreg is irradiated with ultraviolet rays, and the uncured resin will ooze out on the surface, thus satisfying the requirements as a design material. Not preferable.
In the present invention, an α-aminoalkylphenone type photopolymerization initiator and a thioxanthone type photopolymerization start are performed with respect to 100 parts by mass of the radical polymerizable resin containing the components (a), (b), and (c) as essential components. It is necessary that 0.05 to 10 parts by mass of both components of the agent are included. It is particularly preferable that these two components are combined to contain 0.04 to 9 parts by mass.

(Α-aminoalkylphenone type photopolymerization initiator)
The α-aminoalkylphenone type photopolymerization initiator is contained in an amount of 0.04 to 9 parts by mass with respect to 100 parts by mass of the radical polymerizable resin containing the components (a), (b) and (c) as essential components. Is preferred. If the blending amount of the α-aminoalkylphenone type photoinitiator is 0.04 parts by mass or more, curing by ultraviolet rays tends to proceed, and the occurrence of poor curing when irradiated with ultraviolet rays can be suppressed. When this content is 9 parts by mass or less, the α-aminoalkylphenone type photoinitiator is easily dissolved in the components (a), (b), and (c). The more preferable amount of the α-aminoalkylphenone type photoinitiator is 0.1 parts by mass or more and 7 parts by mass or less.

  α-Aminoalkylphenone type photopolymerization initiators include 2-benzyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1- (4 -Morpholinophenyl) -butanone-one and the like, but are not limited thereto.

(Thioxanthone photopolymerization initiator)
On the other hand, the thioxanthone-type photopolymerization initiator is preferably contained in an amount of 0.01 to 9 parts by mass with respect to 100 parts by mass of the radical polymerizable resin containing the components (a), (b) and (c) as essential components. . If the blending amount of the thioxanthone type photopolymerization initiator is 0.01 parts by mass or more, curing by ultraviolet rays is likely to proceed, and the occurrence of poor curing when irradiated with ultraviolet rays can be suppressed. When the amount is 9 parts by mass or less, the thioxanthone type photopolymerization initiator is easily dissolved. A more preferable blending amount of the thioxanthone type photopolymerization initiator is 0.1 parts by mass or more and 7 parts by mass or less.

  Examples of the thioxanthone type photopolymerization initiator include, but are not limited to, 2,4-diethylthioxanthone, 2-chlorothioxanthone, isopropylthioxanthone, and the like.

(Ingredient (e))
Component (e) of the present invention is a thermal polymerization initiator that generates radicals upon heating. The component (e) is mixed in an amount of 0.05 to 10 parts by mass with respect to 100 parts by mass of the radical polymerizable resin containing the components (a), (b) and (c) as essential components. When the amount of component (e) is 0.05 parts by mass or more, the post-curing time for improving heat resistance and toughness can be shortened. If the amount of component (e) is 10 parts by mass or less, poor adhesion of the cured product due to elution of the residue of the thermal polymerization initiator in the cured resin is unlikely to occur. A more preferable amount of the component (e) is 0.5 to 5 parts by mass.

Furthermore, it is preferable that the temperature for obtaining the half-life of 10 hours of this (e) component is 40 degreeC or more and 130 degrees C or less. If this temperature is 40 ° C. or higher, the life of the resin at room temperature is long, and it is preferable because the resin can be easily mixed after the resin viscosity is lowered by heating. On the other hand, if the temperature for obtaining a half-life of 10 hours is 130 ° C. or less, it is preferable because the post-cure temperature for increasing the heat resistance and toughness of the ultraviolet-cured reinforcing fiber composite material can be lowered. Furthermore, the temperature for obtaining a half-life of 10 hours is more preferably 60 ° C. or higher and 110 ° C. or lower.
As the component (e), compounds such as ketone peroxides, peroxyketals, hydroperoxides, diallyl peroxides, diacyl peroxides, peroxyesters, peroxycarbonates or derivatives thereof may be used. It is not something that can be done.

  Commercially available products of these compounds or derivatives thereof include, for example, Parroyl O (Japanese fats and oils), Parroyl L (Japanese fats and oils), Parroyl S (Japanese fats and oils), Perocta O (Japanese fats and oils), Parroyl SA (Japanese fats and oils), Perhexa 250 (Japanese fats and oils), Perhexyl O (Japanese fats and oils), Nyper PMB (Japanese fats and oils), Perbutyl O (Japanese fats and oils), Nyper PMB (Japanese fats and oils), Perbutyl O (Japanese fats and oils), Nyper BMT (Nippon fats and oils), Nyper BW (Japanese fats and oils), Perbutyl IB (Japanese fats and oils), Perhexa MC (Nippon fats and oils), Perhexa TMH (Nippon fats and oils), Perhexa HC (Japanese fats and oils), Perhexa C (Japanese fats and oils), Pertetra A (Japanese fats and oils), Perhexyl I ( Japanese fats and oils), perbutyl MA (Japanese fats and oils), perbutyl 355 (Japanese fats and oils), perb L (Japanese fats and oils), Perhexa 25MT (Japanese fats and oils), Perbutyl I (Japanese fats and oils), Perbutyl E (Japanese fats and oils), Perhexyl Z (Japanese fats and oils), Perhexa V (Japanese fats and oils), Perbutyl P (Japanese fats and oils), Park mill Examples include D (Japanese fats and oils), Perhexyl D (Japanese fats and oils), Perhexa 25B (Nippon fats and oils), Perbutyl D (Nippon fats and oils), Permenta H (Japanese fats and oils), Perhexine 25B (Japanese fats and oils) and the like. It is not limited.

(Physical properties of polymerizable resin composition)
The radical polymerizable resin composition containing at least the essential components (a) to (e) is irradiated with ultraviolet light having a peak illuminance of 400 mW / cm ^{2 on} a monitor of 320 nm to 390 nm, and a light amount of 930 mJ / cm ² is applied to the back surface and the front surface. It is preferable that Tg of the resin cured by irradiation once is 140 ° C. or higher and the bending elongation at break is 6% or higher. Under such conditions of a peak illuminance of 400 mW / cm ^{2 on} a 320 nm-390 nm monitor, the Tg of the resin cured by irradiating the back surface and the surface once with an integrated light amount of 930 mJ / cm ² is 140 ° C. or more. If it exists, it is preferable because the Tg of the fiber-reinforced resin composite material can be increased by post-heating the prepreg after ultraviolet curing. Further, if the bending rupture elongation of the resin cured under the same ultraviolet curing conditions is 6% or more, the fiber reinforced resin composite material has good mechanical strength by post-heating after curing the prepreg with ultraviolet rays. Therefore, it is preferable.

(Reinforced fiber)
The reinforcing fiber used in the present invention is not particularly limited. For example, carbon fiber, graphite fiber, aramid fiber, silicon carbide fiber, alumina fiber, boron fiber, high-strength polyethylene fiber, tungsten carbide fiber, PBO fiber, glass fiber, metal Fiber etc. can be used. Moreover, you may use combining these some reinforcing fiber as needed.
Among these reinforcing fibers, carbon fibers and graphite fibers, when used as reinforcing fibers, have good specific elasticity and specific strength, so they become lightweight, high-strength, high-elasticity fiber-reinforced composite materials. Since a feeling appears, it is suitable for the present invention.

(Sizing agent)
When carbon fiber or graphite fiber is used as the reinforcing fiber, it is easy to impregnate the radical curable resin by using a sizing agent having a compound having at least one (meth) acrylate group and one epoxy group in the molecule as the sizing agent. Furthermore, it is preferable because the adhesive strength between the reinforcing fiber and the radical polymerizable resin is increased.
Examples of such a compound having one (meth) acrylate group and one epoxy group at the end of the main chain include compounds represented by chemical formula III, chemical formula IV, and chemical formula VI, and at least one compound selected from these compounds It is preferable to use an aqueous emulsion prepared using a nonionic surfactant because the radical polymerizable resin is easily impregnated into the reinforcing fiber and the adhesion between the reinforcing fiber and the radical polymerizable resin is improved.
More preferably, when a bisphenol A type compound having an acrylic group and an epoxy group at both ends represented by the chemical formula V is used as a sizing agent, adhesion to reinforcing fibers and impregnation with a radical curable matrix resin are improved. Therefore, it is preferable.

（Ｒ¹、Ｒ²は水素もしくはメチル基である）

(R ¹ and R ² are hydrogen or methyl group)

（Ｒ¹、Ｒ²は水素もしくはメチル基である）

(R ¹ and R ² are hydrogen or methyl group)

（Ｒ¹は水素もしくはメチル基。化学式（VI）は分子中R⁵の部位に（化学式ＶII）および（化学式ＶIII）で表される構造を少なくとも１つづつ有する）

(R ¹ is hydrogen or methyl group. Chemical formula (VI) has at least one structure represented by (chemical formula VII) and (chemical formula VIII) at the site of R ^{5 in} the molecule)

（Ｒ²は水素もしくはメチル基）

(R ² is hydrogen or methyl group)

(Reinforcing fiber shape)
The shape of the reinforcing fiber used in the prepreg of the present invention is not particularly limited, and a reinforcing fiber tow in which the reinforcing fiber filaments are converged, a unidirectional material in which the reinforcing fiber tows are aligned in one direction, a woven fabric, or a short cut Nonwoven fabrics made of reinforced fibers can be used, but it is preferable to use a woven fabric as the reinforced fiber because the design is particularly good due to the depth of appearance, gloss, and the beauty of the geometric pattern of the woven fabric.

  In the case of woven fabrics, stitches are made so as not to unravel the sheets of fiber bundles that are aligned in one direction, such as plain weave, twill weave, satin weave, or non-crimp fabric, or sheets that are laminated at different angles. A stitching sheet etc. can be illustrated.

There are no particular restrictions on the reinforcing fibers of basis weight (weight per fiber 1 m ^{2) but, 10g / m 2 ~650g / m} 2 is preferred. A basis weight of 10 g / m ² or more is preferable because unevenness of the fiber width and openings are less noticeable and the design is improved. A basis weight of 650 g / m ² or less is preferable because the resin impregnation is good and the ultraviolet curable property of the prepreg is good. The basis weight is more is more preferable ^{50~500g / m 2, 50~300g / m} 2 is particularly preferred.

(Method to obtain prepreg)
The method for obtaining the prepreg for fiber reinforced resin composite material from the radical polymerizable resin and the reinforced fiber is not particularly limited. For example, one side or both sides of a reinforcing base material such as a reinforcing fiber tow in which reinforcing fiber filaments are converged, a unidirectional material in which reinforcing fiber tows are aligned in one direction, a woven fabric, or a nonwoven fabric made of short cut reinforcing fibers. A method of producing a prepreg by supplying a resin from the above, heating and pressing to impregnate the resin into the reinforcing fiber fabric is preferably used.

  The amount of the radical polymerizable resin composition used for the prepreg is preferably 30% by mass to 70% by mass. If the amount of the resin composition is 30% by mass or more, it is preferable because the gloss of the cured prepreg surface becomes good, and if it is 70% by mass or less, the mechanical properties are sufficiently expressed.

  Hereinafter, the present invention will be specifically described by way of examples. In addition, the evaluation method in a present Example is as follows.

(Measurement of resin bending elongation)
Using an Instron universal testing machine, the sample size is 2 mm thick, 8 mm wide, 60 mm long, crosshead speed 2 mm / min, span to thickness ratio 16 and 3-point bending test (indenter radius 3.2R, Support radius 3.2R) was performed and the elongation at the time of sample break was recorded as the break elongation.

(Measurement of Tg)
A rheometer G5000 manufactured by UBM was used, the sample size was 12 mm wide and 30 mm long, with a measurement frequency of 1.59 Hz, a 5 ° C. step temperature rise, 1 min. Perform DMA measurement in hold mode. The temperature dependence of the ratio tan δ between the loss elastic modulus G ″ and the storage elastic modulus G ′ was measured. The peak of tan δ was determined from the temperature dependence curve of tan δ, and the temperature at the peak was recorded as Tg.

(Hardening of resin and prepreg)
Curing of the resin and prepreg by ultraviolet irradiation was carried out by LIGHT HAMMER6 manufactured by FUSION. The distance between the light source and the belt was set to 104 mm. For measurement of illuminance and light intensity, UV light meter UV-350 manufactured by Oak Manufacturing Co., Ltd. was passed through a sample moving belt of LIGHT HAMMER6.
The resin is cured once by UV light meter UV-350 manufactured by Oak Manufacturing Co., Ltd., with a peak illuminance of 400 mW / cm2 and an integrated UV light of 930 mJ / cm2 adjusted to a thickness of 2 mm. Carried out.
Curing of the prepreg was performed by irradiating the back and front surfaces of the prepreg once with ultraviolet rays having a peak illuminance of 400 mW / cm 2 and an integrated light amount of 1850 mJ / cm 2 as measured by UV light meter UV-350 manufactured by Oak Manufacturing Co., Ltd.

  Each component used for the resin compositions of the following Examples and Comparative Examples is as indicated by the following abbreviations.

(A) Component Aronix M-315: Trisacryloyloxyethyl isocyanurate (Toagosei)

(B) Component Epoxy ester 3000A: Bisphenol A diglycidyl ether acrylic acid adduct (Kyoeisha Chemical)

(C) Component Kayalad HX220: Caprolactone addition (m + n = 2) diacrylate (Nippon Kayaku) of neopentyl glycol hydroxypivalate

Radical polymerizable acrylic resin other than components (a), (b), (c) NK Oligo U-2PHA: Isophorone diisocyanate-hydroxyethyl acrylate (Shin Nakamura Chemical Co., Ltd.)

  New Frontier BPE-10: EO-modified bisphenol A diacrylate (Daiichi Kogyo Seiyaku)

(D) Component Irgacure 369: α-aminoalkylphenone type photopolymerization initiator 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butan-1-one (Ciba Specialty Chemicals)

  Kayacure ITX: Thioxanthone-type photopolymerization initiator Isopropyl thioxanthone (Nippon Kayaku)

  Kayacure DETX-S: Thioxanthone photopolymerization initiator 2,4-diethylthioxanthone (Nippon Kayaku)

(E) Component Perbutyl O: t-butyl 2-ethyl perhexanoate (Nippon Yushi)

Example 1
As a radically polymerizable resin, 40 parts by mass of Aronix M-315, 30 parts by mass of epoxy ester 3000A, 30 parts by mass of Kayarad HX220, 2 parts by mass of Irgacure 369, 0.4 parts by mass of Kayacure ITX, 1 perbutyl O .5 parts by mass was weighed and mixed until the solid content was dissolved.

The resin was irradiated with a cumulative light amount of 930 mJ / cm ² once on the back surface and the front surface under conditions of a peak illuminance of 400 mW / cm ^{2 on} a 320 nm-390 nm monitor, and cured to a thickness of 2 mm. It was 148 degreeC when Tg of hardened | cured material was measured. Further, the bending elongation at break of the cured product was measured and found to be 8.4%.

  Carbon fiber (carbon fiber TR50S manufactured by Mitsubishi Rayon) formed by converging 12,000 carbon fiber filaments was used as the reinforcing fiber. This carbon fiber bundle was impregnated with a sizing agent solution A by roller and dried with hot air to obtain a sizing agent-attached yarn. This sizing agent solution A has a compound represented by (Chemical Formula 5) as a main component, and a nonionic surfactant (trade name F-88, manufactured by Asahi Denka Co., Ltd.) based on the sizing agent component excluding water. What was blended by mass% and adjusted to an aqueous emulsion having a concentration of 2 mass% was used, and the coating amount of the sizing agent on the carbon fiber bundle was 1.5% by weight.

This sizing agent-attached yarn was woven to form a plain weave fabric with a basis weight of 200 g / m ² , and the radical polymerizable resin was impregnated with a resin content of 50% by mass to prepare a prepreg.

When this prepreg was irradiated with a light amount of 1850 mJ / cm ^{2 on} the back surface and the surface once each under a condition of a peak illuminance of 400 mW / cm ^{2 on} a 320 nm-390 nm monitor, a stain of uncured resin on the surface of the molded body There was no sticking out, and it was confirmed that the prepreg had been cured.
Moreover, this molded object hardened | cured with the ultraviolet-ray was post-cured on 150 degreeC and the conditions for 1 hour, and Tg exceeding 150 degreeC was shown when Tg was measured.
When the molded body obtained above was cut, the cross-section was polished and magnified and observed with an optical microscope (75 times), poor resin impregnation and voids were hardly confirmed, and it was confirmed that the molded body was in a good molding state. .

(Example 2)
The same resin as in Example 1 was used, and carbon fibers (carbon fiber TR50S manufactured by Mitsubishi Rayon) formed by converging 12,000 carbon fiber filaments were used as reinforcing fibers impregnated with this resin. This carbon fiber bundle was impregnated with the sizing agent solution B by a roller and dried with hot air to obtain a sizing agent-attached yarn. The sizing agent solution B was prepared in the same manner as in Example 1 except that a commercially available bisphenol A type epoxy resin (Epicoat 828, manufactured by Japan Epoxy Resin) was used as a main component.
This sizing agent-attached yarn was woven to form a plain weave fabric with a fiber basis weight of 200 g / m ² , and the curable resin was impregnated with a resin content of 50% by mass to prepare a prepreg.

When the prepreg was irradiated with a light amount of accumulated light amount of 1850 mJ / cm ² once each on the back surface and the surface under the condition of peak illuminance of 400 mW / cm ^{2 on} a 320 nm-390 nm monitor, the uncured resin on the surface of the molded body There was no oozing and hardening of the prepreg was confirmed.
The molded body cured with ultraviolet rays was post-cured under conditions of 150 ° C. and 1 hour, and Tg was measured to show Tg exceeding 150 ° C. When this molded body was cut and the cross section was polished and magnified and observed with an optical microscope, poor impregnation and many voids were observed inside the carbon fiber bundle, and resin impregnation was not sufficient.

(Comparative Example 1)
As radically polymerizable resin, weigh 60 parts by weight of epoxy ester 3000A, 40 parts by weight of Kayarad HX220, 2 parts by weight of Irgacure 369, 0.4 parts by weight of Kayacure ITX, 1.5 parts by weight of perbutyl O, solid content The mixture was stirred until dissolved.

The resin was irradiated with a cumulative light amount of 930 mJ / cm ² once on the back surface and the front surface under conditions of a peak illuminance of 400 mW / cm ^{2 on} a 320 nm-390 nm monitor, and cured to a thickness of 2 mm. When Tg of the cured product was measured, it was 95 ° C., and it was confirmed that the heat resistance was insufficient. Further, the bending elongation at break of the cured product was measured and found to be 7.2%.

  The same carbon fiber fabric as in Example 1 was used as the reinforcing fiber, and the resin was impregnated so as to have a content of 50% by mass to prepare a prepreg.

When this prepreg was irradiated with a light amount of 1850 mJ / cm ^{2 on} the back surface and the surface once each under a condition of a peak illuminance of 400 mW / cm ^{2 on} a 320 nm-390 nm monitor, a stain of uncured resin on the surface of the molded body There was no sticking out, and it was confirmed that the prepreg had been cured. Further, this molded body cured with ultraviolet rays was post-cured at 150 ° C. for 1 hour, and Tg was measured. As a result, Tg exceeding 150 ° C. could not be confirmed. Moreover, when this molded body was cut, the cross-section was polished and magnified with an optical microscope, the resin impregnation defect and void were hardly confirmed, and it was confirmed to be in a good state.

(Comparative Example 2)
As a radical polymerizable resin, 40 parts by mass of Aronix M-315, 30 parts by mass of NK Oligo U-2PHA, 30 parts by mass of Kayarad HX220, 2 parts by mass of Irgacure 369, 0.4 parts by mass of Kayacure ITX, perbutyl O Was weighed and mixed until the solid content was dissolved.

The resin was irradiated with a cumulative light amount of 930 mJ / cm ² once on the back surface and the front surface under conditions of a peak illuminance of 400 mW / cm ^{2 on} a 320 nm-390 nm monitor, and cured to a thickness of 2 mm. It was 153 degreeC when Tg of hardened | cured material was measured. Moreover, when the bending fracture elongation of the cured product was measured, it was 4.5%, and it was confirmed that the resin had low toughness.

  The same carbon fiber fabric as in Example 1 was used as the reinforcing fiber, and the resin was impregnated so as to have a content of 50% by mass to prepare a prepreg.

When the prepreg was irradiated with a light amount of accumulated light amount of 1850 mJ / cm ² once each on the back surface and the surface under the condition of peak illuminance of 400 mW / cm ^{2 on} a 320 nm-390 nm monitor, the uncured resin on the surface of the molded body There was no oozing and hardening of the prepreg was confirmed. The molded body cured with ultraviolet rays was post-cured under conditions of 150 ° C. and 1 hour, and Tg was measured to show Tg exceeding 150 ° C. Moreover, when this molded body was cut, the cross-section was polished and magnified with an optical microscope, the resin impregnation defect and void were hardly confirmed, and it was confirmed to be in a good state.

(Comparative Example 3)
As a radical curable resin, 40 parts by mass of Aronix M-315, 30 parts by mass of NK Oligo U-2PHA, 30 parts by mass of New Frontier BPE-10, 2 parts by mass of Irgacure 369, 0.4 parts by mass of Kayacure ITX Then, 1.5 parts by mass of perbutyl O was weighed and mixed with stirring until the solid content was dissolved.

The resin was irradiated with a cumulative light amount of 930 mJ / cm ² once on the back surface and the front surface under conditions of a peak illuminance of 400 mW / cm ^{2 on} a 320 nm-390 nm monitor, and cured to a thickness of 2 mm. When Tg of the cured product was measured, it was confirmed to be 125 ° C. and low heat resistance resin. Further, the bending elongation at break of the cured product was measured and found to be 7.8%.

  The same carbon fiber fabric as in Example 1 was used as the reinforcing fiber and impregnated so that the resin content was 50% by mass to prepare a prepreg.

When the prepreg was irradiated with a light amount of accumulated light amount of 1850 mJ / cm ² once each on the back surface and the surface under the condition of peak illuminance of 400 mW / cm ^{2 on} a 320 nm-390 nm monitor, the uncured resin on the surface of the molded body There was no oozing and hardening of the prepreg was confirmed. Further, this molded body cured with ultraviolet rays was post-cured at 150 ° C. for 1 hour, and Tg was measured. As a result, Tg exceeding 150 ° C. could not be confirmed. Moreover, when this molded body was cut, the cross section was polished and magnified with an optical microscope, the impregnation defect and void were hardly confirmed, and it was confirmed that the impregnation state was good.

(Comparative Example 4)
As a radical curable resin, 40 parts by mass of Aronix M-315, 60 parts by mass of Kayarad HX2200, 2 parts by mass of Irgacure 369, 0.4 parts by mass of Kayacure ITX, 1.5 parts by mass of perbutyl O were measured and solids were measured. Stir and mix until the minutes are dissolved.

The resin was irradiated with a cumulative light amount of 930 mJ / cm ² once on the back surface and the front surface under conditions of a peak illuminance of 400 mW / cm ^{2 on} a 320 nm-390 nm monitor, and cured to a thickness of 2 mm. When Tg of the cured product was measured, it was 131 ° C., and it was confirmed that the resin had low heat resistance. Further, the bending elongation at break of the cured product was measured and found to be 9.0%.

  The same carbon fiber fabric as in Example 1 was used as the reinforcing fiber and impregnated so that the resin content was 50% by mass to prepare a prepreg.

When the prepreg was irradiated with a light amount of accumulated light amount of 1850 mJ / cm ² once each on the back surface and the surface under the condition of peak illuminance of 400 mW / cm ^{2 on} a 320 nm-390 nm monitor, the uncured resin on the surface of the molded body There was no oozing and hardening of the prepreg was confirmed. Further, this molded body cured with ultraviolet rays was post-cured at 150 ° C. for 1 hour, and Tg was measured. As a result, Tg exceeding 150 ° C. could not be confirmed. Moreover, when this molded body was cut, the cross section was polished and magnified with an optical microscope, the impregnation defect and void were hardly confirmed, and it was confirmed that the impregnation state was good.

(Comparative Example 5)
As a radical curable resin, 80 parts by mass of Aronix M-315, 20 parts by mass of Kayarad HX220, 2 parts by mass of Irgacure 369, 0.4 parts by mass of Kayacure ITX, 1.5 parts by mass of perbutyl O were weighed. Stir and mix until the minutes are dissolved.

The resin was irradiated with a cumulative light amount of 930 mJ / cm ² once on the back surface and the front surface under conditions of a peak illuminance of 400 mW / cm ^{2 on} a 320 nm-390 nm monitor, and cured to a thickness of 2 mm. It was 231 degreeC when Tg of hardened | cured material was measured. Moreover, when the bending fracture elongation of the cured product was measured, it was 4.5%, and it was confirmed that the resin had low toughness.

  The same carbon fiber fabric as in Example 1 was used as the reinforcing fiber and impregnated so that the resin content was 50% by mass to prepare a prepreg.

When the prepreg was irradiated with a light amount of accumulated light amount of 1850 mJ / cm ² once each on the back surface and the surface under the condition of peak illuminance of 400 mW / cm ^{2 on} a 320 nm-390 nm monitor, the uncured resin on the surface of the molded body There was no oozing and hardening of the prepreg was confirmed. Moreover, this molded object hardened | cured with the ultraviolet-ray was post-cured on 150 degreeC and the conditions for 1 hour, and Tg exceeding 150 degreeC was shown when Tg was measured. Moreover, when this molded body was cut, the cross section was polished and magnified with an optical microscope, the impregnation defect and void were hardly confirmed, and it was confirmed that the impregnation state was good.

(Comparative Example 6)
As a radical curable resin, 40 parts by mass of Aronix M-315, 30 parts by mass of epoxy ester 3000A, 30 parts by mass of Kayarad HX220 and 2 parts by mass of Irgacure 369 were weighed and mixed until the solid content was dissolved.

  As the reinforcing fiber impregnated with this resin, the same carbon fiber fabric as in Example 1 was used, and impregnated so that the resin content became 50% by mass to prepare a prepreg.

When the prepreg was irradiated with a light amount of 1850 mJ / cm ^{2 on} the back surface and the surface once each under a condition of a peak illuminance of 400 mW / cm ^{2 on} a 320 nm-390 nm monitor, uncured resin was stained on the surface of the molded body. The prepreg was insufficiently cured. Further, the molded body cured with ultraviolet rays was post-cured under conditions of 150 ° C. and 1 hour, and Tg was measured. As a result, no clear tan δ peak was shown, and Tg could not be measured.

(Comparative Example 7)
As a radical curable resin, 40 parts by weight of Aronix M-315, 30 parts by weight of epoxy ester 3000A, 30 parts by weight of Kayarad HX220, and 2 parts by weight of Kayacure DETX-S were weighed and mixed until the solid content was dissolved. .

  As the reinforcing fiber impregnated with this resin, the same carbon fiber fabric as in Example 1 was used, and impregnated so that the resin content became 50% by mass to prepare a prepreg.

When the prepreg was irradiated with a light amount of 1850 mJ / cm ^{2 on} the back surface and the surface once each under the condition of a peak illuminance of 400 mW / cm ^{2 on} a 320 nm-390 nm monitor, the surface of the molded body was uncured resin. It was sticky and the prepreg was insufficiently cured. Further, the molded body cured with ultraviolet rays was post-cured under conditions of 150 ° C. and 1 hour, and Tg was measured. As a result, no clear tan δ peak was shown, and Tg could not be measured.

(Comparative Example 8)
As a radical curable resin, 40 parts by mass of Aronix M-315, 30 parts by mass of epoxy ester 3000A, 30 parts by mass of Kayarad HX220, 1.5 parts by mass of perbutyl O were weighed and mixed.

  As the reinforcing fiber impregnated with this resin, the same carbon fiber fabric as in Example 1 was used, and impregnated so that the resin content became 50% by mass to prepare a prepreg.

When the prepreg was irradiated with a light amount of 1850 mJ / cm ^{2 on} the back surface and the surface once each under the condition of a peak illuminance of 400 mW / cm ^{2 on} a 320 nm-390 nm monitor, the surface of the molded body was uncured resin. It was sticky and the prepreg was insufficiently cured. Further, this prepreg irradiated with ultraviolet rays was post-cured at 150 ° C. for 1 hour, and Tg was measured. As a result, Tg exceeding 150 ° C. was confirmed.

(Comparative Example 9)
As a radical curable resin, 40 parts by mass of Aronix M-315, 30 parts by mass of epoxy ester 3000A, 30 parts by mass of Kayarad HX220, 2 parts by mass of Irgacure 369, 1.5 parts by mass of perbutyl O were measured, and the solid content The mixture was stirred until dissolved.

  As the reinforcing fiber impregnated with this resin, the same carbon fiber fabric as in Example 1 was used, and the radical curable resin was impregnated so that the resin content was 50% by mass to prepare a prepreg.

When the prepreg was irradiated with a light amount of 1850 mJ / cm ^{2 on} the back surface and the surface once each under a condition of a peak illuminance of 400 mW / cm ^{2 on} a 320 nm-390 nm monitor, uncured resin oozes out to the surface of the molded body. The prepreg was not sufficiently cured. Further, this molded body cured with ultraviolet rays was post-cured at 150 ° C. for 1 hour, and Tg was measured. As a result, Tg exceeding 150 ° C. was confirmed.

The results obtained by the comparative examples and examples are summarized in Tables 1 and 2. In these tables, judgment was made by the following method as a judgment result of prepreg curability by ultraviolet irradiation.
A case where the surface was cured and no stickiness due to exudation of the uncured resin even when a force was applied to the surface of the cured prepreg with a finger was rated as ◯. Although the surface was hardened, when force was applied to the hardened prepreg surface with a finger, the internal uncured resin oozed out to the surface, so that a sticky feeling was felt and the internal was judged to be uncured was evaluated as Δ. When the surface of the prepreg after UV irradiation was touched, stickiness remained, and those in which the resin was clearly judged to be uncured were marked as x in Tables 1 and 2.

  Moreover, as a result of the heat resistance measurement after post-curing, those having a Tg of 150 ° C. or higher are shown in Tables 1 and 2 as “◯” and those having a Tg of less than 150 ° C.

The impregnation property of the resin composition into the reinforcing fibers was determined by the following method.
First, the obtained fiber-reinforced composite material is cut with a diamond cutter, and the cut surface is polished by sandpaper and alumina fine particles to remove the cut and abrasive scratches, and then the polishing is performed. The observed surface was magnified and observed with an optical microscope at a magnification of 75 times. In the cut and polished prepreg cross section, a large number of voids and non-impregnated portions were observed. And in Table 2.

Claims (4)

A prepreg for a fiber reinforced resin composite material comprising at least a reinforcing fiber and a radical polymerizable resin composition; the radical polymerizable resin composition comprises the following components (a), (b), (c):
(A) 30-50 parts by mass of a tri (meth) acrylate compound represented by Formula I

(R ¹ is hydrogen or methyl group)
(B) 20-50 parts by mass of (meth) acrylic acid adduct of bisphenol A diglycidyl ether (c) 10-35 parts by mass of di (meth) acrylate compound represented by chemical formula II

(R ¹ is hydrogen or a methyl group, R ³ is a straight chain hydrocarbon group having 3 to 6 carbon atoms, R ⁴ is a branched, cyclic, or straight chain hydrocarbon group having 2 to 15 carbon atoms, or an aromatic ring. A hydrocarbon group having an ester structure in the structure, provided that m + n = 2 to 5)) as an essential component,
(D) 0.05-10 parts by mass of the α-aminoalkylphenone type photopolymerization initiator and the thioxanthone type photopolymerization initiator in combination, and
( E) A prepreg for a fiber reinforced resin composite material, which is a radical polymerizable resin composition containing 0.05 to 10 parts by mass of a thermal polymerization initiator having a temperature for obtaining a half-life of 10 hours of 60 ° C. or higher and 110 ° C. or lower .   (E) The prepreg for fiber-reinforced resin composite material according to claim 1, wherein t-butyl 2-ethylperhexanoate is used as a thermal polymerization initiator.   The prepreg for a fiber-reinforced resin composite material according to claim 1 or 2, wherein carbon fibers are used as the reinforcing fibers.   The prepreg for a fiber reinforced resin composite material according to claim 3, wherein a carbon fiber to which a sizing agent having a compound having at least one (meth) acrylate group and an epoxy group in the molecule is attached is used as the reinforcing fiber.