JP2010031198A - Copolymerized polyamide fine particle and carbon fiber-reinforced composite material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fine particle based on copolymerized polyamide which is effective as a toughness improving agent of a carbon fiber-reinforced composite material. <P>SOLUTION: The fine particle contains the copolymerized polyamide obtained by a polycondensation reaction of (A) 3, 3'-dimethyl-4, 4'-diaminodicyclohexylmethane, (B) terephthalic acid, (C) isophthalic acid and (D) 6-18C aminocarboxylic acid or lactam by the ratios: 0.15<[D]/([A]+[B]+[C]+[D])<0.65 and 0≤[C]/[B]<4 (wherein [A], [B], [C] and [D] are molar numbers of (A), (B), (C) and (D), respectively) and has 1-100 μm median diameter. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  TECHNICAL FIELD The present invention relates to a copolymerized polyamide fine particle effective as a toughness improving material for a thermosetting resin, which is composed of a highly tough copolymerized polyamide as a main component, and a carbon fiber composite material blended with the same.

  Carbon fiber reinforced composite materials containing carbon fibers and matrix resins are excellent in specific strength, specific rigidity, heat resistance and environmental resistance, and are therefore widely used in the sports and aircraft fields. In particular, in the aircraft field, carbon fiber reinforced composite materials having excellent specific strength and specific rigidity have been attracting attention in anticipation of low fuel consumption due to weight reduction due to the recent increase in fuel.

  Among the mechanical properties required for aircraft structural materials, tensile strength and post-impact compressive strength (CAI) are the most important, and many techniques for improving these mechanical properties have been disclosed. Patent Document 1 discloses a technique for improving CAI by so-called particle interlayer reinforcement, in which thermoplastic resin particles are arranged and strengthened between layers. In order to improve CAI, it is considered effective to use a high toughness thermoplastic resin and absorb energy by deformation of the thermoplastic resin at the time of impact. Generally, a high toughness thermoplastic resin has a glass transition temperature. Therefore, a thermoplastic resin having both a high glass transition temperature and a high toughness has been desired.

Patent Documents 2 to 4 disclose copolymer polyamides obtained by polycondensation of aliphatic units, terephthalic acid and / or isophthalic acid, and alicyclic diamines as thermoplastic polyamides having excellent transparency and chemical resistance. ing. However, it has not been described at all that it can be used as a toughness improving material for thermosetting resins by processing such polyamide into fine particles.
Japanese Patent Laid-Open No. 10-231372 Japanese Patent Laid-Open No. 1-135834 JP-A-5-311066 JP-A-5-311067

  An object of the present invention is to provide fine particles, a prepreg, and a carbon fiber composite material mainly composed of a high toughness copolymer polyamide, which is effective as a toughness improving material for thermosetting resins.

  As a result of intensive studies to solve the above problems, the present inventors have found that a copolymerized polyamide obtained by polycondensation of components (A) to (D) at a specific ratio is effective, and reached the present invention. did.

That is, the present invention
(I) (A) 3,3′-dimethyl-4,4′-diaminodicyclohexylmethane, (B) terephthalic acid, (C) isophthalic acid, (D) an aminocarboxylic acid or lactam having 6 to 18 carbon atoms 0.15 <[D] / ([A] + [B] + [C] + [D]) <0, where [A] [B] [C] [D] is the number of moles of each. 65, fine particles having a median diameter of 1 to 100 μm, including a copolymerized polyamide obtained by polycondensation at a ratio of 0 ≦ [C] / [B] <4,
(Ii) The fine particles according to (i), wherein the component (D) is 12-aminododecanoic acid or laurolactam,
(Iii) Fine particles according to (i) or (ii), wherein the glass transition temperature is 130 ° C. or higher and 230 ° C. or lower,
(Iv) The fine particles according to any one of (i) to (iii), further containing a thermosetting resin,
(V) The fine particles according to (iv), wherein 0.1 to 30 parts by weight of a thermosetting resin is contained with respect to 100 parts by weight of the copolymer polyamide,
(Vi) The fine particles according to (iv) or (v), wherein the thermosetting resin is an epoxy resin,
(Vii) a prepreg comprising at least one fine particle selected from the fine particles according to any one of (i) to (vi), a matrix resin, and carbon fibers,
(Viii) a carbon fiber reinforced composite material obtained by curing the prepreg described in (vii),
(Ix) The carbon fiber reinforced composite material is formed by laminating a plurality of layers containing a matrix resin, at least one kind of fine particles selected from the fine particles according to any one of (i) to (vi), and carbon fibers, The fine particles are the carbon fiber reinforced composite material described in (viii), in which 80% by weight or more of the total amount is present in the interlayer region.

  ADVANTAGE OF THE INVENTION According to this invention, the copolymerization polyamide fine particle effective as a toughness improving material of a thermosetting resin can be provided.

  The fine particles of the present invention include (A) 3,3′-dimethyl-4,4′-diaminodicyclohexylmethane, (B) terephthalic acid, (C) isophthalic acid, and (D) an aminocarboxylic acid having 6 to 18 carbon atoms. The main component is a copolyamide obtained by polycondensation of an acid or lactam.

  (D) As aminocarboxylic acid or lactam having 6 to 18 carbon atoms used as component, 6-aminocaproic acid, 7-aminoheptanoic acid, 8-aminooctanoic acid, 9-aminononanoic acid, 10-aminodecanoic acid 11-aminoundecanoic acid, 12-aminododecanoic acid, caprolactam, undecalactam, laurolactam and the like, and these raw materials can be used alone or in the form of a mixture. As the number of carbon atoms increases, the resulting copolymer polyamide has a low water absorption and is excellent in dimensional stability. Therefore, 12-aminododecanoic acid and laurolactam are preferably used.

  In the present invention, when the number of moles of (A), (B), (C), and (D) is [A] [B] [C] [D], respectively, 0.95 <[A] / ([B] + [C]) <1.05 is preferably blended and polycondensed. When [A] / ([B] + [C]) is within the above range, the balance between the amino group and the carboxyl group is good, and the degree of polymerization tends to increase.

  In the present invention, it is necessary that the blending ratio of the component (D) is 0.15 <[D] / ([A] + [B] + [C] + [D]) <0.65. When [D] / ([A] + [B] + [C] + [D]) is 0.15 or less, the toughness tends to decrease. On the other hand, when the amount of copolymerization of the component (D) increases, the glass transition temperature of the copolymerized polyamide tends to decrease. In the present invention, since it is intended to obtain a copolyamide having a high glass transition temperature at the time of water absorption, [D] / ([A] + [B] + [C] + [D]) is set to 0.65. It is necessary to make it less than.

  Furthermore, in the present invention, it is necessary that 0 ≦ [C] / [B] <4. Preferably 0 ≦ [C] / [B] <3, more preferably 0 ≦ [C] / [B] <2. When [C] / [B] is 4 or more, the toughness of the resulting copolymerized polyamide tends to be low.

As a method for producing the copolymerized polyamide used in the present invention, the process is carried out through a step of maintaining the inside of the polymerization system under pressure in the presence of water and producing a prepolymer, which is usually performed in melt polymerization of polyamide. The amount of water charged is preferably 10% by weight or more and 70% by weight or less based on the total amount of raw material and water combined. When water is less than 10% by weight, the raw material tends to have an excessive heat history, which is not preferable. On the other hand, when the amount of water is more than 70% by weight, a great amount of heat energy is consumed for removing the water, and it takes time to produce the prepolymer. Furthermore, the pressure maintained in the pressurized state is preferably 10 kg / cm ² or more and 25 kg / cm ² or less. In the case where it is kept at less than 10 kg / cm ² , (A) the alicyclic diamine tends to volatilize out of the polymerization system, which is not preferable. Moreover, when it hold | maintains higher than 25 kg / cm < ² >, it is necessary to make the temperature in a polymerization system high, and since (A) alicyclic diamine becomes easy to volatilize out of the system as a result, it is unpreferable. After passing through such a prepolymer production step, the pressure is gradually released to normal pressure or reduced pressure to further increase the degree of polymerization of the prepolymer.

  Although it depends on the composition of the copolymerized polyamide, in the present invention, the maximum temperature reached in the polymerization system is preferably 150 ° C. or higher and 330 ° C. or lower, and more preferably 250 ° C. or higher and 320 ° C. or lower. Since the copolymerized polyamide used in the present invention has a high melt viscosity, when the maximum temperature reached in the polymerization system is close to the glass transition temperature of the copolymerized polyamide, the polymer precipitates in the polymerization system and the productivity is greatly increased. This is not preferable. On the other hand, when the temperature is higher than 330 ° C., the resulting copolyamide tends to deteriorate.

  Furthermore, in the present invention, the molecular weight of the copolymerized polyamide can be controlled by adjusting the time during which the interior of the polymerization system is maintained at the glass transition temperature or higher of the copolymerized polyamide at normal pressure or reduced pressure. It is preferable to control the time during which the inside of the polymerization system is maintained at or above the glass transition temperature of the copolymerized polyamide to 3 hours or less. When it is held for 3 hours or more, the degree of polymerization is remarkably increased to increase the viscosity, and there is a possibility that it cannot be discharged.

  The degree of polymerization of the copolymerized polyamide used in the present invention is not particularly limited, but the relative viscosity measured at 25 ° C. in a 98% concentrated sulfuric acid solution having a sample concentration of 0.01 g / ml is 1.5 to 4.0. The thing of the range is preferable and the polyamide resin of the range of 1.7-3.0 is especially preferable. When the relative viscosity is lower than 1.5, the toughness is lowered, and when it is higher than 4.0, it tends to be difficult to process into fine particles.

  The glass transition temperature of the copolymerized polyamide used in the present invention is preferably 130 ° C. or higher and 230 ° C. or lower. In order to satisfy this glass transition temperature, the blending ratio of the components (A) to (D) is 0.15 <[D] / ([A] + [B] + [C] + [D]) <0. .50. The glass transition temperature at the time of water absorption here refers to the temperature at the peak top of tan δ that appears when a viscoelasticity measurement is performed on a molded product of a copolyamide. When the glass transition temperature is less than 130 ° C., when the copolymer polyamide used in the present invention is used as a toughness improving material for a carbon fiber reinforced composite material, the high temperature compressive strength of the composite material during water absorption decreases. Tend. Moreover, when it exceeds 230 degreeC, there exists a tendency for the toughness improvement effect of this composite material to become small.

  When the copolymerized polyamide used in the present invention is used as a toughness improving material for a carbon fiber reinforced composite material, it is necessary to be blended between several μ to several hundred μm between reinforcing fibers. The median diameter of the polymerized polyamide fine particles needs to be 1 to 100 μm. More preferably, it is 3-60 micrometers, Most preferably, it is 6-30 micrometers. When the thickness is larger than 100 μm, the arrangement of the reinforcing fibers is disturbed or the layer of the composite material obtained by lamination is unnecessarily thick. In the case of less than 1 μm, the particles penetrate between the reinforcing fibers and are not localized in the interlayer portion of the prepreg laminate, so that the impact energy cannot be sufficiently absorbed by the particles at the time of impact, and the CAI decreases. There is a tendency.

  Here, the median diameter indicates a median diameter measured by a laser diffraction particle size distribution analyzer based on the so-called Mie scattering / diffraction theory. Specifically, when the particle size distribution curve of the particle size and the solid particle amount is obtained, it means a particle size (so-called 50% particle size) at which the integrated solid particle amount is 50% with respect to the total solid particle amount. is there.

  In addition, a thermosetting resin can be contained for the purpose of controlling the heat resistance, elastic modulus, and adhesion of the carbon fiber reinforced composite material to the matrix resin. The thermosetting resin used in this case is not particularly limited as long as it is a resin that is cured by external energy such as heat, light, or electron beam to form a three-dimensional cured product at least partially. Specific examples include epoxy resins, benzoxazine resins, vinyl ester resins, unsaturated polyester resins, urethane resins, phenol resins, melamine resins, maleimide resins, cyanate ester resins, and urea resins. Among these, an epoxy resin excellent in adhesiveness with the matrix resin of the carbon fiber reinforced composite material is preferably used. As the epoxy resin, for example, a glycidyl ether type epoxy resin obtained from a compound having a hydroxyl group in the molecule and epichlorohydrin, a glycidylamine type epoxy resin obtained from a compound having an amino group in the molecule and epichlorohydrin, A glycidyl ester type epoxy resin obtained from a compound having a carboxyl group in the molecule and epichlorohydrin, an alicyclic epoxy resin obtained by oxidizing a compound having a double bond in the molecule, or 2 selected from these An epoxy resin or the like in which more than one type of group is 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, and bisphenol AD. Bisphenol AD epoxy resin obtained by reaction of epichlorohydrin, resorcinol type epoxy resin obtained by reaction of resorcinol and epichlorohydrin, reaction of phenol novolak, which is a reaction product of phenol and formaldehyde, and epichlorohydrin Obtained phenol novolac type epoxy resin, other polyethylene glycol type epoxy resin, polypropylene glycol type epoxy resin, naphthalene type epoxy resin, and these Substitutions at position isomers and alkyl group or a halogen.

  Commercially available bisphenol A type epoxy resins include “jER” (registered trademark) 827, “jER” (registered trademark) 828 (above, manufactured by Japan Epoxy Resin Co., Ltd.), “Epicron” (registered trademark) 840, “ "Epicron" (registered trademark) 850 (manufactured by DIC Corporation), "Epototo" (registered trademark) YD-128 (manufactured by Toto Kasei Corporation), DER-331, DER-332 (manufactured by Dow Chemical Company), “Bakelite” (registered trademark) EPR162, “Bakelite” (registered trademark) EPR172, “Bakelite” (registered trademark) EPR173, and “Bakelite” (registered trademark) EPR174 (above, manufactured by Bakelite AG) and the like.

  Commercially available products of bisphenol F type epoxy resin include “jER” (registered trademark) 806, “jER” (registered trademark) 807, “jER” (registered trademark) 1750 (above, manufactured by Japan Epoxy Resin Co., Ltd.), “ "Epicron" (registered trademark) 830, "Epiclon" (registered trademark) 835 (manufactured by DIC Corporation), "Epototo" (registered trademark) YD-170, "Epototo" (registered trademark) YD-175 (Toto Kasei) (Manufactured by Co., Ltd.), “Bakelite” (registered trademark) EPR169 (manufactured by Bakerite AG), GY281, GY282, and GY285 (manufactured by Huntsman Advanced Material).

  Examples of commercially available bisphenol AD type epoxy resins include “EPOMIK” (registered trademark) R710, “EPOMIK” (registered trademark) R1710 (manufactured by Printec Co., Ltd.), and the like.

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

  Commercially available phenol novolac type epoxy resins include “jER” (registered trademark) 152, “jER” (registered trademark) 154 (manufactured by Japan Epoxy Resin Co., Ltd.), “Epicron” (registered trademark) 740 (DIC). And EPN179, EPN180 (manufactured by Huntsman Advanced Materials), and the like.

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

  Commercially available tetraglycidyldiaminodiphenylmethanes include “Sumiepoxy” (registered trademark) ELM434 (manufactured by Sumitomo Chemical Co., Ltd.), “Araldite” (registered trademark) MY720, “Araldite” (registered trademark) MY721, “Araldite” ( (Registered trademark) MY9512, “Araldite” (registered trademark) MY9612, “Araldite” (registered trademark) MY9634, “Araldite” (registered trademark) MY9663 (manufactured by Huntsman Advanced Materials), “jER” (registered trademark) 604 (Made by Japan Epoxy Resin Co., Ltd.), “Bakelite” (registered trademark) EPR494, “Bakelite” (registered trademark) EPR495, “Bakelite” (registered trademark) EPR496, and “Bakelite” (registered trademark) EPR497 Or more, manufactured by Bakelite AG, Inc.), and the like.

  Commercially available products of aminophenol glycidyl compounds include “jER” (registered trademark) 630 (manufactured by Japan Epoxy Resin Co., Ltd.), “Araldite” (registered trademark) MY0500, “Araldite” (registered trademark) MY0510 (above Huntsman) Advanced Materials Co., Ltd., “Sumiepoxy” (registered trademark) ELM120, “Sumiepoxy” (registered trademark) ELM100 (manufactured by Sumitomo Chemical Co., Ltd.), and the like.

  Examples of commercially available glycidyl anilines include GAN, GOT (manufactured by Nippon Kayaku Co., Ltd.), “Bakelite” (registered trademark) 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 commercial products of diglycidyl phthalate include “Epomic” (registered trademark) R508 (manufactured by Mitsui Chemicals) and “Denacol” (registered trademark) EX-721 (manufactured by Nagase ChemteX Corporation). It is done.

  Examples of commercially available 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 esters include “jER” (registered trademark) 871 (manufactured by Japan Epoxy Resin Co., Ltd.) and “Epototo” (registered trademark) YD-171 (manufactured by Toto Kasei Co., Ltd.). It is done.

  Commercially available alicyclic epoxy resins include “Celoxide” (registered trademark) 2021P (manufactured by Daicel Chemical Industries), CY179 (manufactured by Huntsman Advanced Materials), “Celoxide” (registered trademark) 2081 (Daicel). Chemical Industry Co., Ltd.) and “Celoxide” (registered trademark) 3000 (Daicel Chemical Industries, Ltd.).

  As these epoxy resins, bifunctional epoxy resins such as bisphenol A type, bisphenol F type and bisphenol AD type are preferable from the viewpoint of heat resistance and toughness.

  The said epoxy resin can be used by 1 type, or 2 or more types.

  Further, a curing agent can be used in combination with an epoxy resin. Examples of the curing agent used in combination with the epoxy resin include aromatic amines, aliphatic amines, polyamide amines, carboxylic acid anhydrides and Lewis acid complexes, acid-based curing catalysts, base-based curing catalysts, and the like. Specific examples of the aromatic amine include diaminodiphenyl sulfone and diaminodiphenylmethane. Specific examples of aliphatic amines include diethylenetriamine, triethylenetetramine, dicyandiamide, tetraethylenepentamine, dipropylenediamine, piperidine, N, N-dimethylpiperazine, triethylenediamine, polyamidoamine, octylamine, laurylamine. , Myristylamine, stearylamine, cocoalkylamine, beef tallow alkylamine, oleylamine, cured beef tallow alkylamine, N, N-dimethyllaurylamine, N, N-dimethylmyristylamine and the like. Of these, aliphatic amines are preferred from the viewpoint of reactivity.

  Commercially available curing agents combined with epoxy resins include 4,4′-diaminodiphenylsulfone (“SumiCure S” (registered trademark) (manufactured by Sumitomo Chemical Co., Ltd.)), 4,4′-diaminodiphenylmethane (MDA- 220 (manufactured by Mitsui Takeda Chemical Co., Ltd.)), dicyandiamide (DICY7 (manufactured by Japan Epoxy Resin Co., Ltd.)), aromatic polyamine ("Ancamin" (registered trademark) 2049 (manufactured by Air Products Japan Co., Ltd.)), Polyamide amines (“Tomide” (registered trademark) 235S, “Tomide” (registered trademark) 296), “Tomide” (registered trademark) 2400 (manufactured by Fuji Kasei Kogyo Co., Ltd.) and the like can be mentioned.

  These curing agents can be used in combination with an appropriate curing aid in order to increase the curing activity. Preferred examples of combining a curing aid with an epoxy resin include an example of combining dicyandiamide with a urea derivative such as 3- (3,4-dichlorophenyl) -1,1-dimethylurea (DCMU) as a curing aid, Examples include a combination of a group 3 amine and a boron trifluoride ethylamine complex as a curing aid, and a combination of a carboxylic acid anhydride or a novolak resin with a tertiary amine as a curing aid.

  The blending amount of the thermosetting resin with respect to 100 parts by weight of the copolymerized polyamide is preferably from 0.1 parts by weight to 30 parts by weight, and most preferably from 0.5 parts by weight to 20 parts by weight. If it exceeds 30 parts by weight, the effect of improving the toughness of the carbon fiber reinforced composite material by the copolymerized polyamide fine particles may be reduced. On the other hand, when the amount is less than 0.1 part by weight, the copolyamide fine particles may be inferior in adhesiveness with a thermosetting resin suitably used as a matrix resin of a carbon fiber reinforced composite material. By setting the content to 0.1 parts by weight or more and 30 parts by weight or less, it is possible to give the copolymer polyamide fine particles with a good balance between the toughness improving effect of the carbon fiber reinforced composite material and the adhesiveness with the matrix resin used therefor.

  The use ratio of the curing agent to the thermosetting resin is preferably a stoichiometric ratio to the thermosetting resin from the viewpoint of heat resistance and reactivity. Moreover, when using a hardening adjuvant, it is preferable that it is 0.001 to 1 equivalent with respect to 1 equivalent of functional groups of a thermosetting resin.

As a method for producing the copolymerized polyamide fine particles of the present invention,
(1) A method of crystallizing a copolyamide and, if necessary, dissolving a thermosetting resin in a good solvent and volatilizing the solvent,
(2) A method in which a copolymerized polyamide and, if necessary, a thermosetting resin are dissolved in a good solvent and then sprayed in a mist and dried;
(3) A method in which a copolyamide and, if necessary, a thermosetting resin are dissolved in a good solvent, and are injected into a poor solvent that does not dissolve the copolyamide and the thermosetting resin, and precipitated.
(4) A copolymerized polyamide and, if necessary, a thermosetting resin are dissolved in a good solvent, and while the solution is stirred, a poor solvent that is not compatible with the solution is gradually added to form particles in the solution. And the like.

  As a good solvent for dissolving the copolymer polyamide used in the methods (1) to (4), hydrocarbons such as pentane, hexane, heptane, benzene, toluene, cyclohexane, petroleum ether, methylene chloride, chloroform, dichloroethane, Examples include halogenated hydrocarbons such as dichloroethylene, 1,1,1-trichloroethylene, trichloroethylene, and carbon tetrachloride, ethers such as diethyl ether, esters such as ethyl acetate, and ketones such as methyl ethyl ketone. May be used in combination.

  A small amount of a solvent such as methanol or ethanol can be used for the purpose of further improving the solubility of the copolymerized polyamide in the above solvent.

  The good solvent to be used is appropriately selected depending on the type of the copolyamide, and the amount thereof is preferably such that the viscosity of the polyamide solution before adding the poor solvent is 0.1 to 800 millipascal seconds. It is preferably set to be in the range of 10 to 500 millipascal seconds, more preferably 50 to 300 millipascal seconds.

  Examples of the poor solvent that is insoluble or hardly soluble in the solution used in the method (3) or (4) include water, and the solubility parameter is separated from the good solvent used for dissolving the copolymerized polyamide. It is preferred to select a solvent. Examples include chloroform as a good solvent, water as a poor solvent, a mixture of chloroform and methanol as a good solvent, water as a poor solvent, chloroform as a good solvent, and a mixture of water and methanol as a poor solvent.

  When the viscosity of the copolymerized polyamide solution is less than 0.1 millipascal seconds, the amount of the solvent in the polyamide solution becomes relatively large, and as a result, the solvent evaporation time becomes long and the productivity tends to be inferior. Furthermore, there is a tendency that particles are easily coalesced by an excess of a good solvent and are difficult to be formed into fine particles.

  On the other hand, when the viscosity of the copolymerized polyamide solution exceeds 800 millipascal seconds, the copolymerized polyamide solution becomes highly viscous, and a large load is applied to the stirrer. There is.

  The temperature during the production of the fine particles is not particularly problematic as long as it is lower than the boiling point of the poor solvent, but is preferably below the boiling point of the good solvent that dissolves the copolymerized polyamide.

  The production of the fine particles can be performed at normal pressure, but can also be performed under pressure in order to suppress volatilization of the solvent.

  In the method (4), an emulsifier can be further added. Specific examples include polyvinyl alcohol, carboxymethylcellulose, hydroxymethylcellulose, hydroxypropylcellulose, hydroxyethylcellulose, modified starch, polyvinylpyrrolidone, gelatin, gum arabic, and casein. A nonionic, anionic and cationic surfactant may be used in combination with the above-described emulsifier, if necessary. These emulsifiers can be added to a copolymerized polyamide solution or a poor solvent that is hardly compatible with the solution. It is also possible to add to both.

  The amount of the emulsifier is preferably 0.01 to 20% by weight in the copolymerized polyamide solution. 0.1 to 15 weight% is further more preferable from the stability of an emulsion.

  Copolymerized polyamide fine particles having a particle diameter of 0.1 to 100 μm are obtained by gradually adding a poor solvent that is insoluble or hardly soluble in the polyamide solution being stirred continuously or intermittently, and by phase inversion emulsification. can get. The stirring speed at that time is preferably 10 to 1000 rpm, and more preferably 50 to 600 rpm because the particle size becomes more uniform.

  The emulsified liquid formed with the copolymerized polyamide fine particles is heated at a temperature at which the good solvent used volatilizes, and is removed while reducing the pressure as necessary. A preferable temperature at this time is less than 100 ° C.

  The slurry from which the good solvent has been removed is subjected to solid-liquid separation by filtration or centrifugal separation, and fine particles can be obtained by washing and drying the obtained solid content.

  In the method (4), it is possible to easily obtain a median diameter of 100 μm or less, and particularly those having a median diameter of 100 μm or less sufficiently exhibit functions as fine particles in various applications.

  In producing the fine particles of the present invention, an appropriate amount of an uncured thermosetting resin that is cured by external energy such as heat or light and at least partially forms a three-dimensional cure is dissolved in a polyamide solution to form spherical fine particles. Spherical copolymer polyamide fine particles having improved heat resistance, chemical resistance, water absorption rate, strength, and the like can be obtained by performing a curing treatment such as heating to obtain a cured body.

  In producing the spherical copolymerized polyamide fine particles of (1) to (4), the copolymerized polyamide solution is further mixed with inorganic substances such as silica, alumina, mica, thermoplastic resin, rubber, pigment, dye, antioxidant, lubricant, An antistatic agent and a plasticizer may be dispersed and dissolved. It is also possible to improve dispersibility and fluidity by adsorbing or coating ultrafine particles such as silica and alumina on the surface of fine particles in an emulsion and / or dry state.

  The prepreg of the present invention contains the above-mentioned copolymerized polyamide fine particles, a matrix resin, and carbon fibers.

  The matrix resin suitably used in the present invention is a thermosetting resin. Specific examples of thermosetting resins include epoxy resins, benzoxazine resins, vinyl ester resins, unsaturated polyester resins, urethane resins, phenol resins, melamine resins, maleimide resins, cyanate ester resins, and urea resins. It is done. Among these, epoxy resins, benzoxazine resins, vinyl ester resins, unsaturated polyester resins, phenol resins and mixtures of these resins have high mechanical properties and are preferably used. In particular, an epoxy resin is particularly preferably used because it is excellent in mechanical properties, has high affinity with fine particles mainly composed of a thermoplastic resin, and is excellent in adhesion to carbon fibers.

  As the epoxy resin, a compound having a plurality of epoxy groups in the molecule is used. Examples of the epoxy resin include bisphenol A type epoxy resin, bisphenol AD type epoxy resin, bisphenol AF type epoxy resin, bisphenol S type epoxy resin, bisphenol F type epoxy resin, novolac type epoxy resin, naphthalene type epoxy resin, and phenol compound. Epoxy resins made from dicyclopentadiene copolymers as raw materials, glycidyl ether type epoxy resins such as biphenyl type epoxy resins and novolac type epoxy resins, glycidyl amine type epoxy resins, and combinations of these resins are preferably used.

  In particular, an epoxy resin selected from bisphenol A, AD, AF, S and F types or a combination thereof is preferably 5 to 50 parts by weight, and a glycidylamine type epoxy resin is preferably 50 to 95 parts by weight. The epoxy resin contained (the total amount of both is 100 parts by weight) is excellent in the balance between mechanical properties and handleability, and is particularly preferably used.

  Further, a curing agent can be used in combination with an epoxy resin. Examples of the curing agent used in combination with the epoxy resin include aromatic amines, aliphatic amines, carboxylic acid anhydrides, imidazole compounds, and Lewis acid complexes. Specific examples of the aromatic amine include diaminodiphenyl sulfone and diaminodiphenylmethane. Specific examples of aliphatic amines include diethylenetriamine, triethylenetetramine, tetraethylenepentamine, dipropylenediamine, piperidine, piperazine, N, N-dimethylpiperazine, triethylenediamine, polyamidoamine, octylamine, laurylamine. , Myristylamine, stearylamine, cocoalkylamine, beef tallow alkylamine, oleylamine, cured beef tallow alkylamine, N, N-dimethyllaurylamine, N, N-dimethylmyristylamine and the like.

  These curing agents can be used in combination with an appropriate curing aid in order to increase the curing activity. Preferred examples of combining a curing aid with an epoxy resin include an example of combining dicyandiamide with a urea derivative such as 3- (3,4-dichlorophenyl) -1,1-dimethylurea (DCMU) as a curing aid, Examples include a combination of a group 3 amine and a boron trifluoride ethylamine complex as a curing aid, and a combination of a carboxylic acid anhydride or a novolak resin with a tertiary amine as a curing aid.

  The use ratio of the curing agent to the thermosetting resin is preferably a stoichiometric ratio to the thermosetting resin from the viewpoint of heat resistance and reactivity. Moreover, when using a hardening adjuvant, it is preferable that it is 0.001 to 1 equivalent with respect to the functional group of a thermosetting resin.

  In the present invention, the thermoplastic resin is dissolved in the matrix resin before curing, and the thermoplastic resin that forms the sea-island structure in the matrix resin after curing, or the thermoplastic resin is dissolved in the matrix resin before curing, and then the matrix after curing. The matrix resin may contain a thermoplastic resin that is compatible with the resin and does not form a sea-island structure. Such thermoplastic resins include carbon-carbon bonds, amide bonds, imide bonds, ester bonds, ether bonds, carbonate bonds, urethane bonds, urea bonds, thioether bonds, sulfone bonds, imidazole bonds, and carbonyl bonds in the main chain. Those having a bond selected from the group consisting of: In particular, one or more resins selected from the group consisting of polysulfone, polyethersulfone, polyetherimide, and polyimide are preferably used. When the thermoplastic resin is mixed, an appropriate viscoelasticity and mechanical properties can be imparted to the epoxy resin by preferably mixing 1 to 20 parts by weight of the thermoplastic resin with respect to 100 parts by weight of the epoxy resin.

  The carbon fibers used in the present invention are preferably continuous fibers. In the present invention, the continuous fiber is a continuous fiber having a length of 10 mm or more, and does not necessarily need to be a continuous fiber throughout the fiber reinforced layer, and there is no particular problem even if it is divided in the middle. If the length of the carbon fiber becomes too short, it may be difficult to sufficiently exert the strength as the reinforcing fiber when the carbon fiber is processed into a composite material. The shape and arrangement of the carbon fibers are not particularly limited, and may be, for example, a single direction, a random direction, a sheet shape, a mat shape, a woven shape, and a braided shape. In particular, for applications that require high specific strength and high specific modulus, an arrangement in which carbon fiber bundles are aligned in a single direction is the most suitable. Are also suitable for the present invention. In general, the carbon fiber bundle has a total fineness of preferably 100 tex or more and 5000 tex or less, and the number of filaments is preferably 3000 or more and 60000 from the viewpoint of excellent handleability and mechanical properties of the obtained CFRP. What is in the following range is preferably used. The fineness of the carbon fiber bundle can be measured according to JIS R 7601 (1986).

  The carbon fiber reinforced composite material (CFRP) of the present invention is preferably formed by laminating a plurality of layers (hereinafter also referred to as a basic CFRP layer) containing matrix resin, polyamide fine particles, and carbon fibers. In such CFRP, in the interlayer region located between the basic CFRP layers, 80% by weight or more of the fine particles mainly composed of polyamide present in the entire carbon fiber reinforced composite material are present. It is preferable. Presence of fine particles mainly composed of polyamide in the interlayer region is considered to reduce the stress due to the deformation of the particles against the interlaminar shear stress applied at the time of impact application and improve post-impact compressive strength. .

  FIG. 1 shows a model cross-sectional view of a CFRP which is an example of the present invention. In FIG. 1, the basic CFRP layer 1, the basic CFRP layer 2, and the basic CFRP layer 3 are laminated in the CFRP. In FIG. 1, the basic CFRP layer 1 has carbon fibers arranged in a direction perpendicular to the paper surface, the basic CFRP layer 2 has carbon fibers arranged in a 45-degree direction with respect to the paper surface, and the basic CFRP layer 3 has The carbon fibers are arranged in a transverse direction parallel to the paper surface.

  Here, the interlayer region is a contact portion between adjacent basic CFRP layers (for example, in the case of FIG. 1, the basic CFRP layer 1 and the basic CFRP layer 2 or the basic CFRP, as shown in the interlayer region 4 in FIG. 1). Layer 2 and the basic CFRP layer 3), where the average thickness of each layer is t, 0.3t of 0.15t in the thickness direction from the surface where the layers contact each other vertically An area with thickness. In order to obtain the effect of the present invention, it is preferable that 80% by weight or more of the fine particles 5 present in the entire CFRP are present in the interlayer region, and the interlayer region satisfying this condition is preferably present in the CFRP. 30% or more, more preferably 50% or more of the total.

  In the present invention, the amount of fine particles mainly composed of polyamide present in the interlayer region can be determined by the following method. First, CFRP is cut perpendicularly to the laminated surface, and the cross section is enlarged 70 times or more to create a photograph of 200 mm × 200 mm or more. Using this cross-sectional photograph, first, the average layer thickness is obtained. The average thickness of the layers is determined by measuring the thickness of at least two laminated portions on five photos at five arbitrarily selected locations and dividing the value by the number of laminated layers. Next, the cross section of the same CFRP is enlarged by 500 times or more to create a photograph of 200 mm × 200 mm or more. Using this photograph, pay attention to one layer and draw a line almost at the center of the layer. Next, two lines having an interval of 30% of the average thickness of the previously obtained layer and two lines having the average thickness of the layer as an interval are drawn symmetrically with respect to the center line. A portion surrounded by two lines having an interval of 30% of the average thickness of the layers in the photograph is an interlayer region. Then, the area of the fine particles mainly composed of polyamide in the interlayer region, and the area of the fine particles mainly composed of polyamide in the portion surrounded by two lines having the average thickness of the layer as an interval are respectively determined. By taking the ratio, the proportion of fine particles mainly composed of polyamide present in the interlayer region can be calculated. This measurement is performed at five or more locations arbitrarily selected between a plurality of layers, and the average ratio is defined as the ratio of fine particles mainly composed of polyamide existing in the interlayer region. The area of fine particles mainly composed of polyamide can be obtained by taking a photograph into image processing software such as Photoshop manufactured by Adobe, and measuring the portion corresponding to the color of the fine particles with the area measurement function. In the present invention, the amount of fine particles mainly composed of polyamide present in the interlayer region is defined by weight%, but the weight ratio is the same as the value obtained by multiplying the previous area ratio by specific gravity. The ratio value is synonymous with the weight ratio value.

  Furthermore, in the present invention, the volume content (Vf) of the carbon fiber in CFRP is not particularly limited, but Vf is 30% or more from the viewpoint that the obtained CFRP is excellent in specific strength and specific elastic modulus. It is preferable that it is 80% or less. Vf can be measured according to JIS K 7075 (1991).

  Such carbon fibers can be obtained by subjecting raw material carbon fibers to electrolytic surface treatment under specific conditions. As the raw material carbon fiber, known carbon fibers such as acrylic, pitch and rayon can be applied. Among them, acrylic carbon fibers obtained by firing acrylic fibers are preferable because high-strength carbon fibers are easily obtained. Taking the case of acrylic carbon fiber as an example, the method for producing raw carbon fiber will be described in detail below.

  The acrylic fiber is obtained by spinning a spinning dope containing an acrylic polymer. As the spinning method, wet, dry, and dry-wet can be applied, but wet or dry-wet where high-strength yarn can be easily obtained is preferable. Is preferred. As the spinning dope, a polyacrylonitrile homopolymer or copolymer component solution or suspension can be used. After spinning the spinning solution, coagulation, washing with water, stretching, and application of an oil agent are performed to obtain acrylic fibers. The acrylic fiber is further flameproofed, carbonized, and further graphitized as necessary. Raw material carbon fiber is obtained through a so-called firing step. The carbonization / graphitization temperature is preferably 1200 ° C. or more and 3000 ° C. or less in an inert atmosphere, the single fiber diameter is 3 μm or more and 8 μm or less, and the amount of electricity during electrolytic surface treatment is preferably 1 to 200 C per gram of carbon fiber.

  After the electrolytic treatment, it is preferable to wash and dry. Moreover, after drying, a sizing agent is applied as necessary, and a carbon fiber suitable for use in the present invention is obtained. The means for applying the sizing agent is not particularly limited. For example, there are a method of immersing in a sizing agent through a roller, a method of contacting a roller to which the sizing liquid is adhered, and a method of spraying the sizing liquid in a mist form. . Further, either a batch type or a continuous type may be used, but a continuous type that can improve productivity and reduce variation is preferable. At this time, it is preferable to control the concentration of the sizing solution, the drying temperature, the yarn tension, and the like so that the amount of the active component of the sizing agent attached to the carbon fiber is uniformly attached within an appropriate range. Moreover, you may vibrate a carbon fiber with an ultrasonic wave at the time of sizing agent provision.

  The drying temperature and drying time are not particularly limited as long as the solvent can be removed. Examples of the solvent used for the sizing agent include water, methanol, ethanol, dimethylformamide, dimethylacetamide, and acetone. Water is preferable from the viewpoint of easy handling and disaster prevention. Therefore, when a compound insoluble or hardly soluble in water is used as a sizing agent, it is preferable to add an emulsifier, a surfactant or the like to make it water dispersible.

  Next, a method suitable for producing the CFRP of the present invention will be described.

  The CFRP of the present invention can be obtained by laminating a prepreg obtained by impregnating carbon fibers with the above-described uncured matrix resin and curing the uncured matrix resin. Various methods can be used for manufacturing the prepreg. For example, a method in which carbon fibers are passed through a heated uncured matrix resin, or an uncured matrix resin is applied in the form of a film on the surface of a release paper using a reverse roll coater and sandwiched from one side or both sides of the carbon fiber. Applying various methods, such as a method of impregnation by heating and pressurizing, a method in which an uncured matrix resin is dissolved in a solvent to form a solution, impregnated with the solution through carbon fiber, and then dried to remove the solvent Can do. The aforementioned fine particles are present in the vicinity of one or both surfaces of the prepreg, and the fine particles are distributed in the CFRP interlayer region obtained by laminating and curing. As a method of allowing the above-mentioned fine particles to be present in the vicinity of one or both surfaces of the prepreg, a resin in which matrix resin and fine particles are mixed is applied in a film form on the surface of a release paper or the like using a reverse roll coater, etc. It is sandwiched from one or both sides and heated and pressurized. Alternatively, the above-mentioned fine particles are dispersed in the vicinity of one or both surfaces of the prepreg.

  The CFRP of the present invention can be produced by using a molding method such as a hand layup method, a filament winding method, and a resin transfer molding method, in addition to a method of curing a plurality of prepregs after lamination.

  The carbon fiber reinforced composite material of the present invention includes, in addition to aircraft members, sports equipment such as tennis rackets and golf shafts, outer plate members such as automobile bumpers and doors, and automobile structural members such as chassis and front side members, etc. Can be applied to.

[Relative viscosity (ηr)]
Measurement was performed using an Ostwald viscometer at a concentration of 0.01 g / ml in 25% sulfuric acid in 98% sulfuric acid.

[Tensile yield stress]
Using an ASTM No. 1 dumbbell prepared by injection molding (SG75H-MIV, Sumitomo Heavy Industries, Ltd. SG75H-MIV, cylinder temperature 280 ° C., mold temperature 80 ° C.), a tensile test was performed according to ASTM-D638 to measure yield stress.

[Izod impact strength]
ASTM-D256 was used using a test piece with a 1/8 inch (3.18 × 10 ⁻³ m) mold notch prepared by injection molding (SG75H-MIV, Sumitomo Heavy Industries, Ltd., cylinder temperature 280 ° C., mold temperature 80 ° C.). The Izod impact test was conducted according to

[Glass transition temperature of copolyamide by viscoelasticity (DMA)]
Injection molding (Sumitomo Heavy Co. SG75H-MIV, a cylinder temperature of 280 ° C. (provided that only 250 ° C. Comparative Example 2), a mold temperature of 80 ° C.) 1/8 inch was prepared by (3.18 × ^{10 -3} m) Notch Measured from 20 ° C. until the glass transition was observed under the condition of bending mode, frequency 1 Hz, distance between chucks 20 mm, temperature rising rate 2 ° C./min. The glass transition temperature during absolute drying was determined from the top temperature. Further, as a sample at the time of water absorption, a sample was used in which a sealed container in which a similar test piece was submerged in 1 L of water was left in a hot air oven at 71 ° C. for 2 weeks.

[Glass transition temperature of fine particles by DSC]
Using a robot DSCRDC220 manufactured by SII, about 5 mg of a sample was precisely weighed in a nitrogen atmosphere, and the glass transition temperature was determined from the stepwise inflection point that appeared when the temperature was raised at a rate of 10 ° C./min.

[Median diameter]
It measured using the laser particle size distribution analyzer (SALD-2100: Shimadzu Corporation Corp. make).

[CFRP CAI]
The prepreg constituting the CFRP is laminated with a configuration of [45 ° / 0 ° / −45 ° / 90 °] 3 s (the symbol s indicates mirror symmetry), and is 177 ° C. at a pressure of 0.6 MPa in an autoclave. Heat curing was performed for 2 hours to obtain CFRP. According to JIS K7089 (1996), this CFRP was cut into a rectangle of 152.4 mm in the 0 degree direction and 101.6 mm in the 90 degree direction, and an average impact was given to this center by a drop weight impact of 5.4 kg at a drop height of 571 mm. Post compression strength was determined. Further, the measurement was performed in a room temperature dry state (25 ° C. ± 2 ° C., relative humidity 50%).

[Interlayer shear strength of CFRP (H / W ILSS)]
Twelve prepregs constituting CFRP were laminated in the 0 degree direction, and heat-cured in an autoclave at a temperature of 177 ° C. and a pressure of 0.6 MPa for 2 hours to obtain CFRP. This CFRP is cut out into a rectangle having a 0 degree direction of 13 mm and a width direction of 6.35 mm in accordance with ASTM D2402-07, and is immersed in warm water at 71 ° C. for 2 weeks in accordance with ASTM D2402-07 to sufficiently absorb water. The interlaminar shear strength was measured under an environment of 82 ° C.

Reference Examples 1-11
Table 1 shows a 30 wt% aqueous solution of an equimolar salt of diamine / dicarboxylic acid prepared from components (A) to (C) at 60 ° C. and component (D), and the total amount of components (A) to (D) is 600 g. It mix | blended so that it might become the composition shown, and it charged in a 3L pressure vessel, sealed, and nitrogen-substituted. The temperature was set to 300 ° C. (however, only Reference Example 7 was 330 ° C.), and heating was started. After the container internal pressure reached 18.0 kg / cm ² , the container internal pressure was maintained at 18.0 kg / cm ² for 1 hour. Thereafter, the internal pressure of the container was released to normal pressure over 1 hour, and held for 10 minutes under reduced pressure (-21 kPa). The maximum temperature reached in the container was 300 ° C. (330 ° C. in Reference Example 7). A copolyamide was obtained by taking out in a strand form from the discharge port at the bottom of the pressure vessel and pelletizing.

The raw materials shown below were used.
MACM: 3,3′-dimethyl-4,4′-diaminodicyclohexylmethane (Laromin C260 (manufactured by BASF))
TPA: terephthalic acid (Mitsui Chemicals)
IPA: Isophthalic acid (manufactured by EI International Chemical)
ADA: 12-aminododecanoic acid (manufactured by Ube Industries)

  In general, polyamides having a high glass transition temperature tend to have poor toughness. Reference Example 2 and Reference Example 3 are compositions in which isophthalic acid, which is one component of the copolymerized polyamides of Reference Example 10 and Reference Example 11, is changed to terephthalic acid, but despite the high glass transition temperature, Izod impact The strength is about 1.7 times, and the copolymerized polyamide which is a constituent component of the fine particles of the present invention has both a high glass transition temperature and a high toughness.

Example 1
100 parts by weight of the copolymerized polyamide obtained in Reference Example 2 was added to a mixed solvent of chloroform / methanol = 643 parts by weight / 214 parts by weight to obtain a uniform solution. While stirring this solution at 450 rpm, 1029 parts by weight of an aqueous solution in which 6% by weight of polyvinyl alcohol (manufactured by Kanto Chemical Co., Ltd.) was dissolved was gradually added dropwise to disperse the copolymerized polyamide solution in water. Thereafter, the solvent was removed, and vacuum drying was performed at 100 ° C. for 12 hours to obtain copolymerized polyamide fine particles.

Examples 2, 3, 7, 8 and Comparative Examples 1-3, 5
100 parts by weight of the copolymer polyamide obtained in Reference Examples 1 to 4, 7 to 9, or 11; 4.80 parts by weight of bisphenol A type epoxy resin (“jER” (registered trademark) 828 manufactured by Japan Epoxy Resin Co., Ltd.) And 1.60 parts by weight of polyamidoamine as a curing agent (“Tomide” (registered trademark) 296 manufactured by Fuji Kasei Kogyo Co., Ltd.) is added to a mixed solvent of chloroform / methanol = 643 parts by weight / 214 parts by weight. Copolymerized polyamide fine particles were obtained in the same manner as in Example 1 except that the homogeneous solution was used.

Example 4
100 parts by weight of the copolymer polyamide obtained in Reference Example 2, 5.05 parts by weight of a bisphenol A type epoxy resin (“jER” (registered trademark) 828 manufactured by Japan Epoxy Resin Co., Ltd.), diaminodiphenylmethane (Mitsui) Except for using a homogeneous solution obtained by adding 1.35 parts by weight of MDA-220, Takeda Chemical Co., Ltd., to a mixed solvent of chloroform / methanol = 643 parts by weight / 214 parts by weight, exactly the same as Example 1. Copolyamide fine particles were obtained by this method.

Example 5, Comparative Example 4
100 parts by weight of the copolyamide obtained in Reference Example 2 or 10, 4.96 parts by weight of a bisphenol F type epoxy resin (“jER” (registered trademark) 807 manufactured by Japan Epoxy Resin Co., Ltd.), diaminodiphenylmethane as a curing agent Except for using a homogeneous solution obtained by adding 1.44 parts by weight (MDA-220, Mitsui Takeda Chemical Co., Ltd.) in a mixed solvent of chloroform / methanol = 643 parts by weight / 214 parts by weight, Example 1 and Copolymerized polyamide fine particles were obtained in exactly the same manner.

Examples 6 and 9
100 parts by weight of the copolymerized polyamide obtained in Reference Example 2 or 5, 4.69 parts by weight of a bisphenol F type epoxy resin (“jER” (registered trademark) 807 manufactured by Japan Epoxy Resin Co., Ltd.), a polyamidoamine which is a curing agent (Fuji Kasei Kogyo Co., Ltd. “Tomide” (registered trademark) 296) 1.71 parts by weight was added to a mixed solvent of chloroform / methanol = 643 parts by weight / 214 parts by weight, except that a homogeneous solution obtained was used. Copolyamide fine particles were obtained in the same manner as in Example 1.

Examples 10-18, Comparative Examples 6-10
In a kneading machine, polyglycidyldiaminodiphenylmethane (TGDDM) (ELM-434 manufactured by Sumitomo Chemical Co., Ltd.) 75 parts, bisphenol F type epoxy resin (“jER” (registered trademark) 807 manufactured by Japan Epoxy Resin Co., Ltd.) 25 parts poly After blending and dissolving 15 parts of ethersulfone (PES) (Sumitomo Chemical Co., Ltd. Sumika Excel PES5003P), 4,4′-diaminodiphenylsulfone (4,4′-DDS) (“Ardur” ( (Registered trademark) 976-1, manufactured by Vantico Inc.) (40 parts) was kneaded to prepare a resin composition. This resin composition was used as a primary resin.

  On the other hand, 75 parts of tetraglycidyl diaminodiphenylmethane (TGDDM) (ELM-434 manufactured by Sumitomo Chemical Co., Ltd.) and 25 parts of bisphenol F type epoxy resin (“jER” (registered trademark) 807 manufactured by Japan Epoxy Resin Co., Ltd.) were used in a kneading apparatus. After mixing and dissolving 15 parts of polyethersulfone (PES) (Sumitomo Chemical Co., Ltd. Sumika Excel PES5003P), 50 parts of the fine particles prepared in Examples 1 to 9 and Comparative Examples 1 to 5 were kneaded. Further, 40 parts of 4,4′-diaminodiphenylsulfone (4,4′-DDS) (“Ardur” 976-1, manufactured by Vantico Inc.) as a curing agent was kneaded to prepare a resin composition. This resin composition was used as a secondary resin.

Two sheets of the primary resin coated with a film on release paper so as to have a basis weight of 35 g / m ² were prepared. While the coated surfaces are facing each other, carbon fibers having 12,000 filaments (Toray Industries, Inc., 'Treca' (registered trademark) T800H-12K) are aligned in one direction and pressed with a heated press roll. the resin impregnated Te, carbon fiber weight per unit area 250 g / ^{m 2,} resin content was obtained 21.9% by weight of the primary prepreg.

Next, two sheets of a secondary resin coated with a film on release paper so as to have a basis weight of 35 g / m ² were prepared. While this secondary resin coating film was face to face, the primary prepreg was passed through and heated and pressurized in the same manner as the primary, and the carbon fiber basis weight was 250 g / m ² and the resin content was 35.9% by weight. A secondary prepreg was produced. This secondary prepreg was used as an intermediate material for CFRP CAI and HW ILSS measurement.

Examples 19 and 20
Two sheets were prepared by coating the release resin on the release paper so that the primary resin prepared in Example 10 had a basis weight of 60 g / m ² . While the coated surfaces are facing each other, carbon fibers having 12,000 filaments (Toray Industries, Inc., 'Treca' (registered trademark) T800H-12K) are aligned in one direction and pressed with a heated press roll. Thus, a primary prepreg having a carbon fiber basis weight of 250 g / m ² and a resin content of 32.4% by weight was obtained. When laminating this primary prepreg, the fine particles produced in Examples 6 and 8 were uniformly dispersed using a sieve so that the basis weight was 10 g / m ^2, and the prepreg laminate having a resin content of 35.9 wt%. Got. This prepreg laminate was cured and used as a CFRP CAI and HW ILSS measurement material.

  As shown in Table 3, in order to obtain a carbon fiber reinforced composite material having an excellent balance between CAI and H / W ILSS, it has a specific copolymer composition shown in Reference Examples 1 to 5 in Table 1, high toughness, high This can be achieved by blending fine particles mainly composed of a copolyamide having a glass transition temperature.

It is a model sectional view of CFRP which is an example of the present invention.

Explanation of symbols

1 Basic CFRP layer 2 Basic CFRP layer 3 Basic CFRP layer 4 Interlayer region 5 Fine particles

Claims (9)

(A) 3,3′-dimethyl-4,4′-diaminodicyclohexylmethane, (B) terephthalic acid, (C) isophthalic acid, (D) aminocarboxylic acids having 6 to 18 carbon atoms or lactam moles Is [A] [B] [C] [D], 0.15 <[D] / ([A] + [B] + [C] + [D]) <0.65, 0 Fine particles having a median diameter of 1 to 100 μm, including a copolymerized polyamide obtained by polycondensation at a ratio of ≦ [C] / [B] <4. The fine particle according to claim 1, wherein the component (D) is 12-aminododecanoic acid or laurolactam. The fine particles according to claim 1 or 2, wherein the glass transition temperature of the copolymerized polyamide is 130 ° C or higher and 230 ° C or lower. The fine particles according to any one of claims 1 to 3, further comprising a thermosetting resin. 5. The fine particles according to claim 4, wherein 0.1 to 30 parts by weight of a thermosetting resin is contained with respect to 100 parts by weight of the copolyamide. The fine particles according to claim 4 or 5, wherein the thermosetting resin is an epoxy resin. A prepreg comprising at least one fine particle selected from the fine particles according to claim 1, a matrix resin, and carbon fibers. A carbon fiber reinforced composite material obtained by curing the prepreg according to claim 7. The carbon fiber reinforced composite material is formed by laminating a plurality of layers containing a matrix resin, at least one kind of fine particles selected from the fine particles according to any one of claims 1 to 6, and carbon fibers, and the total amount of the fine particles is The carbon fiber reinforced composite material according to claim 8, wherein 80% by weight or more of is present in an interlayer region.

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