JP2011190430A - Thermosetting resin composition and fiber-reinforced prepreg - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a composite material excellent in interlayer impact strength and to provide a prepreg excellent in surface tack retainability. <P>SOLUTION: A thermosetting resin composition comprises [A] an epoxy resin, [B] a thermoplastic resin, [C] fine elastomer particles and [D] fine silica particles as essential components, and includes 5-40 pts.mass component [B] and 12-40 pts.mass component [C] based on 100 pts.mass component [A]. A fiber-reinforced prepreg prepared by laminating a sheet-like material or materials of the composition on one side or both sides of a basic fiber-reinforced prepreg is also provided. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a thermosetting resin composition and a fiber reinforced prepreg.

  The fiber reinforced plastic is an anisotropic material composed of reinforced fibers and a matrix resin, and a sheet-like precursor called a fiber reinforced prepreg in which the reinforced fibers are impregnated with an uncured resin is laminated for the production, A technique for obtaining an object by curing after molding is widely used. In the following description, unless otherwise specified, the term “composite material” is used to mean a fiber reinforced plastic obtained by laminating, molding and curing a prepreg.

  A composite material using a thermosetting resin as a matrix resin is insufficient in impact resistance, reflecting that the matrix resin has low toughness. Therefore, various methods have been proposed for the purpose of improving physical properties other than the fiber axis direction, particularly impact resistance, and interlayer toughness. In particular, a material different from the matrix resin is disposed between the layers to absorb the fracture energy. Many methods have been proposed.

  Patent Document 1 shows that the compressive strength after impact (CAI) of a fiber-reinforced plastic is improved by sticking a resin composition containing fine particles of a thermoplastic resin to the prepreg surface. However, there is a problem that the thermosetting resin component on the surface of the prepreg is absorbed inside the prepreg with time and the tackiness on the surface of the prepreg is insufficient. Usually, a prepreg is laminated on a mold, etc., and then heated and pressed to form. However, if the surface of the prepreg is insufficiently tucked, the sticking to the mold or prepreg will be weakened. Work becomes difficult.

  In Patent Document 2, it is shown that a composite material having improved impact resistance can be obtained while maintaining tackiness by arranging long fibers made of a thermoplastic resin randomly oriented on the surface of a prepreg. However, when the long fibers are randomly oriented, the long fibers made of the thermoplastic resin have a very bulky structure. At this time, since the long fiber made of thermoplastic resin retains more thermosetting resin, when the matrix resin having a relatively low viscosity is used, the surface matrix resin is formed on the long fiber layer made of thermoplastic resin. There is a problem that the tack on the surface of the prepreg is abruptly lowered by being sucked in gradually.

  On the other hand, Patent Document 3 shows that a resin composition containing rubber fine particles can improve the impact resistance of a fiber reinforced plastic, but in a strength test that requires toughness between fiber reinforced plastic layers such as CAI. Has a problem that the effect does not appear.

  Patent Document 4 shows that CAI is improved by pre-reacting a liquid elastomer and using a resin composition in which resin flow is suppressed for a prepreg. However, since it is necessary to pre-react liquid rubber, there exists a problem that the cost for preparing a resin composition starts.

WO94 / 16003 pamphlet JP-A 63-170428 JP-A-9-25393 JP-A-60-63229

  An object of the present invention is to provide a prepreg excellent in surface tack and tack retention and excellent in impact resistance between layers after curing in order to solve the problems of the prior art as described above.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that the problems can be solved by the resin composition and prepreg having the following constitution, and have completed the present invention. That is, this invention consists of the following matters.

1) Including essential components [A], [B], [C] and [D], with respect to 100 parts by mass of component [A], component [B] is 5 to 40 parts by mass, and component [C] ] Is a fiber reinforced prepreg obtained by bonding a sheet-like material of a thermosetting resin composition having a mass of 12 parts by mass or more and 40 parts by mass or less to one side or both sides of a base fiber reinforced prepreg.
[A] Epoxy resin [B] Thermoplastic resin [C] Elastomer fine particles [D] Silica fine particles

2) The minimum viscosity of the thermosetting resin composition when the temperature is increased at a rate of 2 ° C./min is 1000 P or more, and the thixotropy index (η ₁₀₀ / η) of the thermoplastic resin composition at 60 ° C. The fiber-reinforced prepreg according to 1) above, wherein _0.1 ) is 10 or more.

3) The fiber-reinforced prepreg according to 1) or 2) above, wherein the basis weight of the thermosetting resin composition bonded to one side or both sides of the base fiber-reinforced prepreg is 10 g / m ² or more and 45 g / m ² or less.

4) Including essential components [A], [B], [C] and [D], with respect to 100 parts by mass of component [A], component [B] is 5 to 40 parts by mass, and component [C] ] Is 12 to 40 parts by mass of thermosetting resin composition.
[A] Epoxy resin [B] Thermoplastic resin [C] Elastomer fine particles [D] Silica fine particles

  5) The thermosetting resin composition according to 4) above, wherein at least a part of the thermoplastic resin of component [B] is dissolved in the epoxy resin of component [A].

  6) Thermosetting as described in 4) or 5) above, wherein the thermoplastic resin of component [B] is one or more selected from the group consisting of polyethersulfone, polyetherimide, polyvinyl formal and phenoxy resin. Resin composition.

7) The thermosetting resin composition according to any one of 4) to 6) above, wherein the elastomer fine particles of component [C] are crosslinked elastomer fine particles.
8) The thermosetting resin composition according to any one of 4) to 6) above, wherein the elastomer fine particles of component [C] are crosslinked elastomer fine particles and / or core-shell type elastomer fine particles.
9) The epoxy resin composition according to any one of 4) to 8), wherein the component [D] silica fine particles are contained in an amount of 0.8 parts by mass or more with respect to 100 parts by mass of the component [A] epoxy resin.
10) A composition of a thermosetting resin constituting a sheet-like material to be bonded to one side and / or both sides of a base fiber-reinforced prepreg, and the fracture toughness value indicated by the cured product is used for the base fiber-reinforced prepreg. The epoxy resin composition according to any one of 4) to 9) above, which is higher than a fracture toughness value of a cured product obtained by curing a matrix resin.

  The resin composition of the present invention has a very high flow suppressing effect and a high fracture toughness value after curing. For this reason, by sticking the resin composition of the present invention processed into a sheet to the base prepreg surface, it is possible to obtain a prepreg having excellent surface tack and tack retention, and excellent impact resistance between layers after curing. it can.

It is a graph used when calculating | requiring G'-Tg.

  Examples of the epoxy resin that is the constituent component [A] of the present invention include a glycidyl ether type epoxy resin obtained from a compound having a hydroxyl group in the molecule and epichlorohydrin, a compound having an amino group in the molecule, and epichlorohydride. Glycidylamine type epoxy resin obtained from phosphorus, glycidyl ester type epoxy resin obtained from a compound having a carboxyl group in the molecule and epichlorohydrin, a compound having a double bond in the molecule, and an alicyclic ring Epoxy resin or epoxy resin in which two or more types of groups selected from these are mixed in the molecule is used.

  Specific examples of the glycidyl ether type epoxy resin include bisphenol A type epoxy resin obtained by reaction of bisphenol A and epichlorohydrin, bisphenol F type epoxy resin obtained by reaction of bisphenol F and epichlorohydrin, resorcinol and epi Resorcinol type epoxy resin obtained by reaction of chlorohydrin, phenol novolac type epoxy resin obtained by reaction of phenol and epichlorohydrin, other trisphenol novolak type epoxy resin, polyethylene glycol type epoxy resin, polypropylene glycol type epoxy resin, Examples thereof include naphthalene type epoxy resins, dicyclopentadiene type epoxy resins, and their positional isomers, substituted groups with alkyl groups and halogens.

  Commercially available products of bisphenol A type epoxy resin include EPON825, jER826, jER828, jER828 (above, manufactured by Mitsubishi Chemical Corporation), Epicron 850 (DIC Corporation), Epototo YD-128 (Toto Kasei Co., Ltd.) ), DER-331, DER-332 (manufactured by Dow Chemical Co., Ltd.), Bakelite EPR154, Bakelite EPR162, Bakelite EPR172, Bakelite EPR173, and Bakelite EPR174 (manufactured by Bakelite AG).

  As commercial products of bisphenol F type epoxy resin, jER806, jER807, jER1750 (above, manufactured by Mitsubishi Chemical Corporation), Epicron 830 (manufactured by DIC Corporation), Epototo YD-170, Epototo YD-175 (Toto Kasei ( Co., Ltd.), Bakelite EPR169 (manufactured by Bakerite AG), GY281, GY282, and GY285 (above, manufactured by Huntsman Advanced Material), and the like.

  Examples of commercially available resorcinol type epoxy resins include Denacol EX-201 (manufactured by Nagase ChemteX Corporation).

  Commercial products of phenol novolac type epoxy resins include jER152, jER154 (above, manufactured by Mitsubishi Chemical Corporation), Epicron 740 (made by DIC Corporation), and EPN179, EPN180 (above, manufactured by Huntsman Advanced Materials). Etc.

  Examples of the trisphenol novolac type epoxy resin include Tactix 742 (manufactured by Huntsman Advanced Material), EPPN501H, EPPN501HY, EPPN502H, EPPN503H (manufactured by Nippon Kayaku Co., Ltd.), jER1032 (manufactured by Mitsubishi Chemical Corporation), and the like. It is done.

  Specific examples of the glycidylamine type epoxy resin include tetraglycidyldiaminodiphenylmethanes, glycidyl compounds of aminophenol, glycidylanilines, and glycidyl compounds of xylenediamine.

  Commercially available products of tetraglycidyldiaminodiphenylmethanes include Sumiepoxy ELM434 (Sumitomo Chemical Co., Ltd.), Araldite MY720, Araldite MY721, Araldite MY9512, Araldite MY9612, Araldite MY9634, Araldite MY9663 (manufactured by Huntsman Advanced Materials) jER604 (manufactured by Mitsubishi Chemical Corporation), Bakelite EPR494, Bakelite EPR495, “Bakelite EPR496, and Bakelite EPR497 (above, manufactured by Bakelite AG) and the like.

  Commercially available glycidyl compounds such as aminophenol and aminocresol include jER630 (Mitsubishi Chemical Corporation), Araldite MY0500, Araldite MY0510, Araldite MY0600 (manufactured by Huntsman Advanced Materials), Sumiepoxy ELM120, and Sumiepoxy ELM100. (Above, manufactured by Sumitomo Chemical Co., Ltd.).

  Examples of commercially available glycidyl anilines include GAN, GOT (manufactured by Nippon Kayaku Co., Ltd.), Bakelite EPR493 (manufactured by Bakelite AG), and the like. Examples of the glycidyl compound of xylenediamine include TETRAD-X (manufactured by Mitsubishi Gas Chemical Co., Inc.).

  Specific examples of the glycidyl ester type epoxy resin include phthalic acid diglycidyl ester, hexahydrophthalic acid diglycidyl ester, isophthalic acid diglycidyl ester, dimer acid diglycidyl ester and various isomers thereof.

  Examples of commercially available products of diglycidyl phthalate include Epomic R508 (manufactured by Mitsui Chemicals) and Denacol EX-721 (manufactured by Nagase ChemteX Corporation).

  Examples of commercially available products of hexahydrophthalic acid diglycidyl ester include Epomic R540 (manufactured by Mitsui Chemicals) and AK-601 (manufactured by Nippon Kayaku Co., Ltd.).

  Examples of commercially available dimer acid diglycidyl ester include jER871 (manufactured by Mitsubishi Chemical Corporation) and Epototo YD-171 (manufactured by Toto Kasei Co., Ltd.).

Commercially available alicyclic epoxy resins include Celoxide 2021P (manufactured by Daicel Chemical Industries), CY179 (manufactured by Huntsman Advanced Materials), Celoxide 2081 (manufactured by Daicel Chemical Industries, Ltd.), and Celoxide 3000 ( Daicel Chemical Industries, Ltd.).
It is preferable to use an epoxy resin having a rigid structure such as an oxazolidone ring, naphthalene, dicyclopentadiene, anthracene, xanthene, or biphenyl in the skeleton because heat resistance, toughness, and rigidity can be improved.
Examples of the epoxy resin having an oxazolidone ring in the skeleton include AER4152, AER4151, LSA4311, LSA4313, and LSA7001 (manufactured by Asahi Kasei E-Materials Corporation).
Examples of the epoxy resin having a naphthalene skeleton in the skeleton include HP-4032, HP-4700 (manufactured by DIC Corporation), NC-7300 (manufactured by Nippon Kayaku Co., Ltd.), and the like.
Examples of the epoxy resin having a dicyclopentadiene skeleton in the skeleton include XD-100 (manufactured by Nippon Kayaku Co., Ltd.) and HP7200 (manufactured by DIC Corporation).
Examples of the epoxy resin having an anthracene skeleton in the skeleton include YL7172YX-8800 (manufactured by Mitsubishi Chemical Corporation).
Examples of the epoxy resin having a xanthene skeleton in the skeleton include EXA-7335 (manufactured by DIC Corporation).

  Any of these component [A] epoxy resins can be used according to their properties, but among them, bisphenol A type epoxy resins and bisphenol F type epoxy resins can be obtained at low cost. It is preferable because of its excellent balance of heat resistance and toughness. In addition, it is preferable that a part of the component [A] epoxy resin is a solid epoxy resin at room temperature because tackiness and form retention of the prepreg can be provided. In particular, it is preferable to use a trisphenol novolac-type epoxy resin or an epoxy resin having an oxazolidone ring in the skeleton because both high toughness and heat resistance can be achieved. Moreover, said epoxy resin can be used by 1 type (s) or 2 or more types.

  The constituent component [B] of the present invention is a thermoplastic resin. This thermoplastic resin originally has the effect of increasing the viscosity of the epoxy resin composition by being blended with the epoxy resin composition, but by combining with other essential components in the present invention, the epoxy resin composition can be specifically used. It is possible to suppress a decrease in viscosity during curing and to exhibit high thixotropic properties. For this reason, in the prepreg of the present invention, the surface tack retention performance is excellent, and when a composite material is used, a resin layer serving as a shock absorbing layer is formed between the layer structures, and excellent impact resistance is obtained.

  Examples of such thermoplastic resins include polysulfone, polyetherimide, polyphenylene ether, polyamide, polyacrylate, polyaramid, polyester, polycarbonate, polyphenylene sulfide, polybenzimidazole, polyimide, polyethersulfone polyketone, polyetherketone, polyketone. A group of thermoplastic resins belonging to engineering plastics such as ether ether ketone and polyvinyl formal is more preferably used. Polyimide, polyetherimide, polysulfone, polyethersulfone, polyvinyl formal, and the like are particularly preferably used because of excellent heat resistance, toughness, and handleability.

  The blending form of the thermoplastic resin can take any form. For example, a powdered thermoplastic resin is kneaded and dispersed in an epoxy resin using a kneader or the like, or heated in an epoxy resin so that the thermoplastic resin is dissolved in the epoxy resin. By doing so, the viscosity reduction during hardening of an epoxy resin composition can be suppressed, and high thixotropic property can be expressed. In particular, it is preferable to dissolve at least a part of the thermoplastic resin in the epoxy resin because the effect of developing thixotropy is high.

  The particle size of the powdered thermoplastic resin is preferably 200 μm or less because the thixotropic property of the epoxy resin composition becomes higher. Although there is no restriction | limiting in particular in the minimum of a particle size, since the dispersion | distribution to an epoxy resin becomes easy, the thing of 0.2 micrometers or more is preferable.

  Moreover, it is preferable that these thermoplastic resins have a functional group reactive with the thermosetting resin from the viewpoint of improving toughness and maintaining the environmental resistance of the cured resin. Particularly preferred functional groups include a carboxyl group, an amino group, and a hydroxyl group.

  It is preferable that at least a part of the thermoplastic resin of component [B] is dissolved in the epoxy resin of component [A]. In this case, since the viscosity reduction in the curing process of the epoxy resin composition is suppressed, it becomes easy to form a resin layer between the layers of the laminate, and the impact resistance between the layers can be improved.

  Content with respect to the epoxy resin of component [A] of the thermoplastic resin of component [B] is the range of 5 mass parts or more and 40 mass parts or less with respect to 100 mass parts of epoxy resins. If it is 5 parts by mass or more, the effect of impact resistance is sufficiently obtained, and further, by combining with other essential components in the present invention, specifically suppresses a decrease in viscosity during curing of the epoxy resin composition, High thixotropy can be expressed. If it is 40 mass parts or less, kneading | mixing of resin can be performed, without the viscosity of a resin composition becoming high too much. A more preferable range is 6 parts by mass or more and 24 parts by mass or less.

  The component [C] of the present invention is an elastomer fine particle. Elastomer fine particles have the feature that stable physical properties such as toughness can be obtained because the morphology does not change depending on the kind of epoxy resin matrix and curing conditions, but it is combined with other essential components in the present invention. Thus, it is possible to specifically suppress a decrease in viscosity during curing of the epoxy resin composition and to exhibit high thixotropic properties. For this reason, the prepreg of the present invention has excellent surface tack retention performance, and when a composite material is used, a resin layer serving as a shock absorbing layer is formed between the layer structures, and excellent impact resistance can be obtained.

  Examples of the elastomer fine particles include particles obtained by copolymerizing a single or a plurality of unsaturated compounds and a crosslinkable monomer.

  Examples of unsaturated compounds include aliphatic olefins such as ethylene and propylene, aromatic vinyl compounds such as styrene and methylstyrene, conjugated diene compounds such as butadiene, dimethylbutadiene, isoprene, and chloroprene, methyl acrylate, propyl acrylate, and acrylic acid. Examples thereof include unsaturated carboxylic acid esters such as butyl, methyl methacrylate, propyl methacrylate and butyl methacrylate, and vinyl cyanide such as acrylonitrile.

  Furthermore, as the unsaturated compound, a carboxyl group, an epoxy group, a hydroxyl group and an amino group, a compound having a functional group reactive with a curing agent, or the like such as an amino group or an amide group can be used. Examples include acrylic acid, glycidyl methacrylate, vinyl phenol, vinyl aniline, acrylamide and the like.

  Examples of the crosslinkable monomer include compounds having a plurality of polymerizable double bonds in the molecule, such as divinylbenzene, diallyl phthalate, and ethylene glycol dimethacrylate.

These elastomer fine particles can be produced by various conventionally known polymerization methods such as an emulsion polymerization method and a suspension polymerization method. A typical emulsion polymerization method is a method in which an unsaturated compound and a crosslinkable monomer are subjected to emulsion polymerization in the presence of a radical polymerization initiator such as a peroxide, a molecular weight regulator such as a mercaptan or a halogenated hydrocarbon, and an emulsifier. In this method, after reaching the polymerization conversion rate, a reaction stopper is added to stop the polymerization reaction, and then the unreacted monomer in the polymerization system is removed by steam distillation or the like to obtain a copolymer latex. Water is removed from the latex obtained by the emulsion polymerization method to obtain crosslinked rubber particles. Moreover, a commercial item can also be used. Examples of commercially available crosslinked rubber particles include XER-91 (made by Japan Epoxy Resin Co., Ltd.) made of a crosslinked product of a carboxyl-modified butadiene-acrylonitrile copolymer, BPF307 made of acrylic rubber fine particles, and BPA 328 (Japan). Catalyst) and YR-500 series (manufactured by Toto Kasei Co., Ltd.).
Core-shell type elastomer fine particles may be used as the elastomer fine particles. The core-shell type elastomer fine particles can prevent the fusion of the elastomer fine particles and improve the compatibility with the matrix resin by changing the Tg and composition of the shell portion. As a result, the blending amount can be increased. For this reason, since the toughness improvement of cured | curing material and control of thixotropy become easy, it is preferable.

Core shell type elastomer fine particles include Zefiac series such as Zefiac F351 and Staphyroid series (manufactured by Ganz Kasei Co., Ltd.), Metabrene series such as Metabrene S-2001 and Metabrene C-223A (Mitsubishi Rayon Co., Ltd.). And GEINOPELL P52 (manufactured by Wacker Chemie).
Among the core-shell type fine particles, the use of a type that swells in an epoxy resin by heating, such as Zefiac F351, is preferable because an effect of suppressing a decrease in viscosity during curing of the epoxy resin composition is increased.

The elastomer fine particles as described above may be used in combination of a plurality of varieties.
The average particle size of the elastomer fine particles is preferably 10 μm or less, more preferably 5 μm or less, and even more preferably 0.5 μm or less. When the particle size is too large, the tack retaining ability of the prepreg may be weakened.

  Content with respect to the epoxy resin of the component [A] of the elastomer fine particles of the component [C] is in a range of 12 parts by mass or more and 40 parts by mass or less with respect to 100 parts by mass of the epoxy. If it is 12 parts by mass or more, the effect of impact resistance can be sufficiently obtained, and if it is 40 parts by mass or less, the resin composition can be kneaded without excessively increasing the viscosity of the resin composition. A more preferable range is 15 parts by mass or more and 30 parts by mass or less, and further preferably 20 parts by mass or less.

  The component [D] of the present invention is silica fine particles, and specifically, wet silica, phased silica, fumed silica and the like are used. In order to express the tack retaining performance of the prepreg and suppress the resin flow in the curing process, it is preferable to use fumed silica at least in part. In general, silica fine particles have the effect of imparting thixotropic properties to the epoxy resin by appropriately controlling the shape of the fine particles and the functional groups on the surface of the fine particles, but in combination with other essential components in the present invention, It is possible to suppress a decrease in viscosity during curing of the epoxy resin composition and to exhibit high thixotropic properties. For this reason, the prepreg of the present invention has excellent surface tack retention performance, and when a composite material is used, a resin layer serving as a shock absorbing layer is formed between the layer structures, and excellent impact resistance can be obtained.

  It is preferable to react a hydrophobic functional group on the surface of the silica fine particles because it becomes easier to impart thixotropic properties. The particle size of the silica fine particles is preferably 0.1 μm or less because the thixotropic modification effect is high, and more preferably 0.02 μm or less. Examples of commercially available fumed silica include A series such as Aerosil A300, RY series such as RY300 (manufactured by Nippon Aerosil Co., Ltd.), and the like.

  Content with respect to the epoxy resin of component [A] of the silica fine particle of component [D] is 0.8 mass part or more with respect to 100 mass parts of epoxy. When 0.8 parts by mass or more is contained, by combining with other essential components, it is possible to specifically suppress a decrease in viscosity during curing of the epoxy resin composition and to exhibit high thixotropic properties. For this reason, the prepreg of the present invention has excellent surface tack retention performance, and when a composite material is used, a resin layer serving as a shock absorbing layer is formed between the layer structures, and excellent impact resistance can be obtained. More preferably, it is the range of 1.3 to 10 mass parts. If it is 1.3 parts by mass or more, there is an effect of suppressing the decrease in viscosity during curing of the epoxy resin composition and exhibiting high thixotropy, and an epoxy resin layer is formed between the layers, and the impact resistance effect is sufficient Is obtained. If it is 10 mass parts or less, it can knead | mix uniformly to a resin composition. A more preferable range is 1.5 parts by mass or more and 5 parts by mass or less, and further preferably 3 parts by mass or less.

  The resin composition of the present invention can be processed into a sheet-like material and can exhibit an effect by being bonded to one side or both sides of the base fiber-reinforced prepreg. Furthermore, the fracture toughness value of the cured product of the thermoplastic resin held on one side and / or both sides of the base fiber reinforced prepreg is the fracture toughness of the cured product obtained by curing the matrix resin used for the base fiber reinforced prepreg. If the value is higher than the value, the impact resistance of the composite material formed by laminating and curing the prepreg is preferable.

  There is no restriction | limiting in particular as a method of sticking the resin composition processed into the sheet form to a base fiber reinforced prepreg, What is necessary is just to use the processing method of a general prepreg. For example, if the resin composition is applied in a sheet form on a release paper using a coater and processed into a sheet form, and bonded to a base fiber reinforced prepreg separately prepared using a prepreg manufacturing apparatus, It is preferable because the basis weight of the resin composition is easy to control.

In addition, it is preferable that the fabric weight of the resin composition processed into the sheet form is 10 g / m ² or more and 45 g / m ² or less. If it is 10 g / m ² or more, it is preferable because the holding performance of tack as a prepreg and the impact resistance of the composite material can be expressed. On the other hand, if it is 45 g / m ² or less, it is not necessary to reduce the resin amount of the base fiber-reinforced prepreg, and it is preferable because it does not affect the impregnation property.

<Measurement of minimum viscosity>
A rheometer DSR200 manufactured by Rheometrics was used. Using a parallel plate with a diameter of 25 mm, the thickness of the epoxy resin composition between the parallel plates was 0.5 mm, the measurement was started from 30 ° C. under the conditions of an angular velocity of 10 radians / second and a heating rate of 2 ° C./min. Viscosity measurements were taken until The lowest complex viscosity when plotting the complex viscosity obtained against temperature was recorded as the lowest viscosity.

<Measurement of thixotropic properties>
A rheometer DSR200 manufactured by Rheometrics was used. Using a parallel plate with a diameter of 25 mm, the thickness of the epoxy resin composition between the parallel plates was 0.5 mm, and the viscosity was measured at 60 ° C. under conditions of angular velocities of 100 radians / second and 0.1 radians / second. Η ₁₀₀ / η _0.1 when the measured viscosity at an angular velocity of 0.1 radians / second was η _0.1 and the measured viscosity at an angular velocity of 100 radians / second was η ₁₀₀ was defined as the thixotropic index.

<Production of cured resin plate>
A cured resin plate used for measurement of the glass transition temperature, the bending property of the cured resin, and the fracture toughness value of the cured resin was produced by the following procedure. The resin composition prepared by the procedure described in the description of each example and comparative example described later is injected between two glass plates sandwiching a spacer of polytetrafluoroethylene having a predetermined thickness, and a temperature increase rate of 1.7 ° C. / And cured at 180 ° C. for 2 hours under a curing condition to obtain a cured resin plate.

<Molding of fiber reinforced composite material>
A fiber-reinforced composite material used for measurement of glass transition temperature and compressive strength after impact (CAI) was prepared by the following procedure. A laminate in which prepregs were laminated in a predetermined laminate configuration was placed in a bag, which was heated in an autoclave at 180 ° C. for 2 hours and cured to produce a molded plate (fiber reinforced composite material). During this time, the inside of the autoclave was pressurized to 0.7 MPa, and the inside of the bag was kept in vacuum.

<Measurement of glass transition temperature>
Based on the SACMA 18R-94 method, the glass transition temperature of the cured resin obtained by curing the thermosetting resin composition and the fiber reinforced composite material was measured. A cured resin plate produced to a thickness of 2 mm was processed into a test piece having a length of 55 mm and a width of 12 mm, and a fiber reinforced composite material produced by laminating 12 sheets in the direction of [0 °] was 55 mm in length (fiber direction). Processed into a 12 mm wide test piece, using a rheometer ARES-RDA manufactured by Rheometrics, with a measurement frequency of 1 Hz, a heating rate of 5 ° C./min, and a strain of 0.01%, the distance between chucks was 45 mm, The temperature dependence of the storage elastic modulus G ′ was measured from 30 ° C. to the rubber elastic region. Log G ′ is plotted against temperature, and the temperature obtained from the intersection of the approximate straight line of the flat region of log G ′ and the approximate straight line of the region where G ′ transitions is recorded as the glass transition temperature G′−Tg (FIG. 1). reference).

<Measurement of fracture toughness value (GIc) of cured resin>
The test piece was prepared and tested in an environment of a temperature of 20 ° C. and a humidity of 50% RH in accordance with a SENB (Single Edge Nominated Bend) test method compliant with ASTM D5045. A test piece having a length of 27 mm, a width of 3 mm, and a thickness of 6 mm was prepared using a resin plate obtained by curing a thermosetting resin composition, and then a notch was made with a wet diamond cutter, and a razor degreased with MEK was attached to the tip of the notch. A pre-crack was created by sliding while pressing. A fracture toughness test was performed on the prepared test piece using an universal testing machine manufactured by Instron.

<Evaluation of tack>
Tack evaluation of the prepreg was performed in an environment of room temperature 22 ° C. and humidity 50 RH%. The prepreg was allowed to stand in an environment of room temperature 22 ° C. and humidity 50 RH% for 1 hour, and then the protective film on the prepreg surface was peeled off, and tack evaluation was performed by a tactile sensation test. Similarly, the prepreg from which the protective film was peeled was allowed to stand for 24 hours in an environment at room temperature of 22 ° C. and humidity of 50 RH%, and tack evaluation was similarly performed by a tactile sensation test.
Evaluation result ○: Although the tack is sufficient for sticking, the tack is strong and the handleability is slightly poor.
Evaluation results A: Tack is moderate and the handleability is excellent.
Evaluation results Δ: Tack is slightly weak and handling is poor.
Evaluation result ×: Tack is too weak, so handling is poor.

<Measurement of compressive strength after impact (CAI)>
12 laminates obtained by superposing 3 sets of 4 prepregs laminated in the direction of [+ 45 ° / 0 ° / −45 ° / 90 °], and [90 ° / −45 ° / 0 ° / + 45 °] ] Are stacked so that the 90 ° direction is aligned with each other and placed in a bag as a total of 24 laminates, which are placed in an autoclave for 180 Heated at 2 ° C. for 2 hours and cured to produce a molded plate (fiber reinforced composite material). During this time, the inside of the autoclave was pressurized to 0.7 MPa, and the inside of the bag was kept in vacuum.

A test piece was cut out from the obtained molded plate, and a 25 J or 30 J drop weight impact was applied to the center of the test piece in accordance with Airbus Industries Test Method AITM 1.0010, and then the compression strength of the test piece after impact was measured. It was measured.
In this test, since the influence of Vf (fiber volume content) of the test piece is small, the measurement value is an actual measurement value not converted to Vf.
The obtained results are shown in Tables 3 and 4.

<Description of raw materials used in Examples and Comparative Examples>
EPPN502H: trisphenol novolac type epoxy resin, manufactured by Nippon Kayaku Co., Ltd. jER630: p-aminophenol type epoxy resin, manufactured by Mitsubishi Chemical Corporation LSA7001: epoxy resin having an oxazizolidone ring skeleton. Asahi Kasei E-materials Co., Ltd. jER807: Bisphenol F type epoxy resin, Mitsubishi Chemical Co., Ltd. jER828: Bisphenol A type epoxy resin, Mitsubishi Chemical Co., Ltd. GAN: Diglycidyl aniline type epoxy resin, Nippon Kayaku ( RY300 manufactured by KK: Fumed silica with hydrophobic functional groups reacted on the surface, BPF307 manufactured by Evonik Co., Ltd .: Mixture of crosslinked acrylic elastomer fine particles and bisphenol F type epoxy resin, MX960 manufactured by Nippon Shokubai Co., Ltd. Mixture of elastomer fine particles and bisphenol A type epoxy resin, manufactured by Kaneka Corporation
Zefiac F351; core-shell type acrylic rubber fine particles, manufactured by Ganz Kasei Co., Ltd. E2020P micro: polyethersulfone having a hydroxyl group at the terminal, average particle size 20 μm, manufactured by BASF ULTEM 1040: polyetherimide, manufactured by SABIC Innovative Plastics YP50S: phenoxy Resin, manufactured by Tohto Kasei Co., Ltd. Vinylec E: Polyvinyl formal, manufactured by Chisso Co., Ltd. 3,3′-DDS: 3,3′-diaminodiphenyl sulfone, amine type curing agent, manufactured by Nippon Synthetic Chemical Industry Co., Ltd. What was grind | pulverized until the particle size of 98 mass% or more became 10 micrometers or less with the jet mill was used.

Examples 1-18, Comparative Examples 1-9
Of the components shown in Table 1, components [A], [C] (excluding Zefiac F351) and component [B] were weighed and dissolved in an epoxy resin, put into a separable flask, 180 By rotating the stirring rod with a three-one motor while heating at 0 ° C., the amount of the component [B] dissolved in the epoxy resin was dissolved in the epoxy resin. Thereafter, the mixture is allowed to cool to about 70 ° C., an amount not dissolved in the epoxy resin with component [B], Zefiac F351, which is component [D], and component [C], and a curing agent are weighed in and heated to 70 ° C. While using a vacuum pump, the inside of the flask was decompressed to defoam the epoxy resin composition to obtain an epoxy resin composition. The evaluation results are shown in Tables 1 and 2.

Example 19
<Preparation of prepreg>
The raw material is put into a separable flask at the following composition ratio, and the stirring rod is rotated with a three-one motor at a temperature of 120 ° C., and stirring is performed until E2020P micro is dissolved in the epoxy resin, thereby obtaining a base resin. It was.

Base resin composition ratio jER630 30 parts by mass GAN 30 parts by mass E2020P micro 35 parts by mass

Next, each component was weighed at the following catalyst resin composition ratio, and 3,3′-DDS as a curing agent was dispersed with three rolls to prepare a catalyst resin.
Composition ratio of catalyst resin jER630 40 parts by mass 3,3′-DDS 58 parts by mass

The base resin and the catalyst resin were weighed at the following ratios and kneaded in a kneader preheated to 65 ° C. to obtain an epoxy resin composition for a base fiber-reinforced prepreg.
Base resin 95 parts by weight Catalyst resin 98 parts by weight

The obtained base epoxy resin composition for fiber-reinforced prepreg was applied onto release paper so as to have a basis weight of 34 g / m ² with a comma coater to obtain a resin film.
A prepreg was produced by a prepreg machine using two resin films and a carbon fiber having a strand strength of 6200 MPa and a strand elastic modulus of 310 GPa by a double film method. The obtained prepreg having a carbon fiber basis weight of 190 g / m ² and a resin mass fraction of 26% by mass was used as a base fiber-reinforced prepreg.

Next, the resin composition obtained in Example 1 was coated on a release paper with a basis weight of 30 g / m ² using a comma coater to obtain a resin film. The obtained resin film was placed on the surface of the base fiber reinforced prepreg, and a fiber reinforced prepreg was obtained by pasting it with a fusing press at 50 ° C., 0.1 MPa, and a residence time of 10 seconds. The carbon fiber basis weight of the obtained prepreg was 190 g / m ² , and the resin mass fraction was 34% by mass.
The evaluation results of this prepreg are shown in Table 3. This prepreg had sufficient tack and was excellent in tack holding performance. However, the tack was strong and the handling of the prepreg was somewhat poor. The CAI was high.

Comparative Example 10
A fiber reinforced prepreg was produced under the same conditions as in Example 19 except that the resin composition to be bonded to the surface of the base fiber reinforced prepreg was the same as the epoxy resin composition used for the base fiber reinforced prepreg. The evaluation results of this prepreg are shown in Table 3. This prepreg showed sufficient tack. However, the tack was strong and the handling of the prepreg was somewhat poor. In addition, the tack after 24 hours was slightly weak and the CAI was low.

Comparative Example 11
The raw material is put into a separable flask at the following composition ratio, and the stirring rod is rotated with a three-one motor at a temperature of 120 ° C., and stirring is performed until E2020P micro is dissolved in the epoxy resin, thereby obtaining a base resin. It was.
Base resin composition ratio jER630 30 parts by mass GAN 30 parts by mass E2020P micro 35 parts by mass

Next, each component was weighed at the following catalyst resin composition ratio, and a catalyst resin was prepared by dispersing 3,3′-DDS as a curing agent with three rolls.
Composition ratio of catalyst resin jER630 40 parts by mass 3,3′-DDS 58 parts by mass

The base resin and the catalyst resin were weighed at the following ratios and kneaded in a kneader preheated to 65 ° C. to obtain an epoxy resin composition for a base fiber-reinforced prepreg.
Base resin 95 parts by weight Catalyst resin 98 parts by weight

The obtained base epoxy resin composition for fiber-reinforced prepreg was coated on a release paper with a basis weight of 49 g / m ² using a comma coater to obtain a resin film.
A fiber reinforced prepreg was produced by a prepreg machine using two resin films and a carbon fiber having a strand strength of 6200 MPa and a strand elastic modulus of 310 GPa. The obtained prepreg had a carbon fiber basis weight of 190 g / m ² and a resin mass fraction of 34% by mass.
The evaluation results of this prepreg are shown in Table 3.
This prepreg had a sufficient tack, but the tack was strong and the handling of the prepreg was somewhat poor. Further, the tack after 24 hours was weak and the CAI was also low.

Comparative Example 12
The raw material is put into a separable flask at the following composition ratio, and the stirring rod is rotated with a three-one motor at a temperature of 120 ° C., and stirring is performed until E2020P micro is dissolved in the epoxy resin, thereby obtaining a base resin. It was.
Base resin composition ratio jER630 30 parts by mass GAN 30 parts by mass E2020P micro 35 parts by mass

Next, each component was weighed at the following catalyst resin composition ratio, and a catalyst resin was prepared by dispersing 3,3′-DDS as a curing agent with three rolls.
Composition ratio of catalyst resin jER630 40 parts by mass 3,3′-DDS 58 parts by mass

The base resin and the catalyst resin were weighed at the following ratios and kneaded in a kneader preheated to 65 ° C. to obtain an epoxy resin composition for a base fiber-reinforced prepreg.
Base resin 95 parts by weight Catalyst resin 98 parts by weight

The obtained epoxy resin composition for fiber-reinforced prepreg was coated on a release paper with a basis weight of 45 g / m ² with a comma coater to obtain a resin film.
A prepreg was produced by a prepreg machine using two resin films and a carbon fiber having a strand strength of 6200 MPa and a strand elastic modulus of 310 GPa. The obtained fiber reinforced prepreg had a carbon fiber basis weight of 190 g / m ² and a resin mass fraction of 32% by mass. This prepreg was used as a base prepreg. Nylon 12 non-woven fabric (7.5 g / m ² ) obtained by the melt-blowing method is placed on the base prepreg, and a prepreg is obtained by pasting with a fusing press under conditions of 110 ° C., 0.2 MPa, residence time 60 seconds. It was.
The evaluation results of this prepreg are shown in Table 3.
Although this prepreg showed a high CAI value, the tack was weak and the handleability was poor. In addition, the tack after 24 hours was weak and the handleability was poor.

Example 20
A prepreg was prepared in the same manner as in Example 19. However, the composition ratio of the base resin and the catalyst resin was as follows.
Base resin composition ratio jER630 30 parts by mass GAN 23 parts by mass E2020P micro 30 parts by mass Catalyst resin composition ratio jER630 30 parts by mass jER828 17 parts by mass 3,3'-DDS 54.5 parts by mass The ratio of the base resin to the catalyst resin is as follows: It was as follows.
Base resin 83 parts by mass Catalyst resin 101.5 parts by mass

The resin composition to be bonded to the surface of the base fiber reinforced prepreg was the same as in Example 15. Carbon fibers having a strand strength of 5560 MPa and a strand elastic modulus of 264 GPa were used.
The evaluation results of this prepreg are shown in Table 4.
This prepreg had an appropriate tack and excellent workability. In addition, an appropriate tack was retained even after 24 hours, and the tack retaining performance was excellent. Further, CAI was higher and better than Comparative Example 13 using the same carbon fiber and base resin.

Example 21
A prepreg was prepared in the same manner as in Example 19. However, the same resin composition as in Example 18 was used as the resin composition to be bonded to the surface of the base fiber-reinforced prepreg.
The evaluation results of this prepreg are shown in Table 4.
This prepreg had an appropriate tack and excellent workability. In addition, an appropriate tack was retained even after 24 hours, and the tack retaining performance was excellent. Further, CAI was higher and better than Comparative Example 13 using the same carbon fiber and base resin.

Comparative Example 13
A prepreg was produced in the same manner as in Example 19. However, the basis weight of the resin film prepared from the base resin was 48 g / m ^2, and no additional resin composition was attached to the surface of the base fiber-reinforced prepreg.
The evaluation results of this prepreg are shown in Table 4.
This prepreg had a sufficient tack, but the tack was strong and the handling of the prepreg was somewhat poor. Further, the tack after 24 hours was weak and the CAI was also low.

  INDUSTRIAL APPLICATION Since this invention can give the composite material which is excellent in impact resistance, and the prepreg which is excellent in the surface tack retention, it is industrially useful.

Claims (10)

Including essential components [A], [B], [C] and [D], with respect to 100 parts by mass of component [A], component [B] is 5 to 40 parts by mass, and component [C] is A fiber-reinforced prepreg obtained by bonding a sheet-like material of a thermosetting resin composition of 12 parts by mass or more and 40 parts by mass or less to one side or both sides of a base fiber-reinforced prepreg.
[A] Epoxy resin [B] Thermoplastic resin [C] Elastomer fine particles [D] Silica fine particles The minimum viscosity of the thermosetting resin composition when the temperature is increased at a rate of 2 ° C./min is 1000 P or more, and the thixotropy index (η ₁₀₀ / η _{0 of the} thermosetting resin composition at 60 ° C. The fiber-reinforced prepreg according to claim 1, wherein _.1 ) is 10 or more. The fiber-reinforced prepreg according to claim 1 or 2, wherein the basis weight of the thermoplastic resin composition bonded to one side or both sides of the base fiber-reinforced prepreg is 10 g / m ² or more and 45 g / m ² or less. Including essential components [A], [B], [C] and [D], with respect to 100 parts by mass of component [A], component [B] is 5 to 40 parts by mass, and component [C] is The thermosetting resin composition which is 12 mass parts or more and 40 mass parts or less.
[A] Epoxy resin [B] Thermoplastic resin [C] Elastomer fine particles [D] Silica fine particles   The thermosetting resin composition according to claim 4, wherein at least a part of the thermoplastic resin of component [B] is dissolved in the epoxy resin of component [A].   The thermosetting resin composition according to claim 4 or 5, wherein the thermoplastic resin of component [B] is one or more selected from the group consisting of polyethersulfone, polyetherimide, polyvinyl formal and phenoxy resin. .   The thermosetting resin composition according to any one of claims 4 to 6, wherein the elastomer fine particles of component [C] are crosslinked elastomer fine particles.   The thermosetting resin composition according to any one of claims 4 to 6, wherein the elastomer fine particles of component [C] are crosslinked elastomer fine particles and / or core-shell type elastomer fine particles.   The epoxy resin composition according to any one of claims 4 to 8, wherein component [D] is contained in an amount of 0.8 parts by mass or more with respect to 100 parts by mass of component [A].   A matrix resin used for a base fiber reinforced prepreg, which is a composition of a thermosetting resin constituting a sheet-like material to be bonded to one side and / or both sides of a base fiber reinforced prepreg, and whose fracture toughness value indicated by the cured product is used for the base fiber reinforced prepreg The epoxy resin composition in any one of Claims 4-9 higher than the fracture toughness value of the hardened | cured material obtained by hardening | curing.

Images