JP7124390B2 - Conductive prepreg, composite material and composite laminate using the same - Google Patents

Description

TECHNICAL FIELD The present invention relates to a conductive prepreg, a composite material using the same, and a composite material laminate.

Fiber reinforced composite materials, which consist of fiber reinforced materials and matrix resins, have features such as light weight, high strength, and high elastic modulus, and are widely used as a substitute for metals in aircraft, sports/leisure, and general industries. However, the fiber-reinforced composite material has a low-conductivity matrix resin between the fiber-reinforced materials. Therefore, even if conductive fibers are used as the fiber reinforced material, there is a problem that the conductivity of the fiber reinforced composite material is much lower than that of metal due to the matrix resin between the fibers.

Therefore, as a method for improving the conductivity in the thickness direction of the fiber-reinforced composite material, conductive particles are arranged in the resin layer between the fiber layers of the fiber-reinforced composite material, and the conductivity between the two fiber layers (Patent Document 1), and a method of adding a conductive filler having a small particle size to a matrix resin and introducing a conductive material into the fiber layer (Patent Document 2).
Further, a thermosetting resin composition having electrical conductivity utilizing the network effect of a conductive polymer, which is an organic material, without using a conductive inorganic filler is disclosed (Patent Document 3).

Japanese Patent Publication No. 2011-519749 JP 2014-141656 A JP 2015-010202 A

In both Patent Documents 1 and 2, a conductive metal-containing inorganic filler is dispersed in a resin, and the conductivity is greatly affected by the content of the inorganic filler. It was difficult. In addition, although Patent Document 3 does not use an inorganic filler, it is lightweight, but the disclosed thermosetting resin composition undergoes a monomer reaction even while the composition is stored before curing. Therefore, there are problems such as low storage stability, insufficient interfacial adhesion with fiber-reinforced materials, and low mechanical properties, making it difficult to develop applications for structural members.

Therefore, the present invention provides a conductive prepreg having excellent conductivity, and a composite material and a composite material laminate in which warpage is reduced and appearance is improved while the conductive prepreg has excellent conductivity. The challenge is to

As a result of intensive studies to solve the above problems, the present inventors have conceived the following invention and found that the problems can be solved.
That is, the present invention is as follows.

[1] A sheet-like prepreg that satisfies the following (1) and (2) and contains carbon fibers and a resin composition,
The resin composition comprises a conductive polymer (A), a protonic acid dopant (B), a compound (C) having an alicyclic skeleton and an epoxy group, an epoxy compound (D) other than the compound (C), and curing. A conductive prepreg containing an agent (E).
(1) The coefficient of linear thermal expansion of the conductive prepreg after curing is 1.0×10 ⁻⁷ /° C. or more and 9.0×10 ⁻⁵ /° C. or less (2) The volume resistivity of the conductive prepreg after curing is 1.0×10 ⁻⁶ Ω·cm or more and 1.0×10 ⁶ Ω·cm or less [2] A cured composite material comprising the conductive prepreg.
[3] A laminate having the composite material and a composite material other than the composite material, wherein at least one layer of the composite material is provided on at least one surface of the laminate.

ADVANTAGE OF THE INVENTION According to the present invention, a conductive prepreg having excellent conductivity, and a composite material and a composite laminate having an improved appearance by reducing warpage while having excellent conductivity of the conductive prepreg are provided. can do.

<Conductive prepreg>
The conductive prepreg of the present invention is
A sheet-like prepreg that satisfies the following (1) and (2) and contains carbon fibers and a resin composition,
The resin composition comprises a conductive polymer (A), a protonic acid dopant (B), a compound (C) having an alicyclic skeleton and an epoxy group, an epoxy compound (D) other than the compound (C), and a curing agent. It is characterized by containing (E).
(1) The coefficient of linear thermal expansion of the conductive prepreg after curing is 1.0×10 ⁻⁷ /° C. or more and 9.0×10 ⁻⁵ /° C. or less (2) The volume resistivity of the conductive prepreg after curing is 1.0×10 ⁻⁶ Ω・cm or more and 1.0×10 ⁶ Ω・cm or less

The resin composition used in the present invention is a thermosetting conductive resin composition. In the resin composition, the protonic acid dopant (B) functions as a dopant component for the conductive polymer (A), and the compound (C) having an alicyclic skeleton and an epoxy group (hereinafter simply referred to as "compound (C) ), it also works as a polymerization initiator. The conductive polymer (A) is uniformly dispersed in the protonic acid dopant (B), and by suitably adjusting the content ratio of each component, the conductive polymer is uniformly dispersed in the resin composition. Due to the composite containing (A) and the protonic acid dopant (B), the cured product of the resin composition has excellent electrical conductivity.
Further, by using the compound (C) as a monomer, the polymerization reaction of the monomer hardly occurs even during storage of the resin composition before curing, and the storage stability of the resin composition is excellent. can be expressed. Compound (C) has a cycloaliphatic skeleton epoxy group, a high weight-average molecular weight, and a complicated steric structure. Compounds having such a structure are thought to have the effect of greatly reducing the reaction rate of cationic polymerization due to hindrances such as side chains and steric structures during the polymerization reaction. In addition, the oxygen of the epoxy group in the compound (C) becomes negatively charged, and when it approaches the protonic acid dopant (B) having positive ions, the negative oxygen and the positive carbon bond and polymerize, resulting in a chain reaction-like reaction. It is also thought that there is little change in binding energy and that it does not lead to a temperature rise. For the above reason, it is considered that the use of the compound (C) hardly causes the polymerization reaction of the monomer at about room temperature.

Further, the resin composition contains the compound (C) and an epoxy compound (D) other than the compound (C), thereby adjusting the viscosity so that the resin composition is well impregnated into the fiber reinforced material containing carbon fibers. It becomes possible to design storage stability and curability.
As described above, the resin composition has excellent storage stability, so that the physical properties of the resin composition are maintained even when it is used for a conductive prepreg, and the prepreg has excellent conductivity. In addition, the resin composition does not use conventional inorganic conductive fillers and low-molecular-weight reactive monomers, and is lightweight by introducing a network of the conductive polymer (A) into a high-molecular-weight epoxy polymer. and conductivity.
Furthermore, since the resin composition has excellent adhesion (interfacial adhesion) to the carbon fiber contained in the fiber reinforced material, the strength of the pre-greg and the strength of the laminate of the pre-greg and other pre-greg are improved. It tends to exhibit its characteristics sufficiently. In addition, the laminate has a low interlaminar interface strength and reduces warpage caused by curing shrinkage of the resin, thereby exhibiting an effect of improving the appearance of the laminate. Therefore, by using the conductive prepreg of the present invention, the conductive prepreg can be laminated together with commercially available carbon fiber prepreg while maintaining the excellent conductivity of the conductive prepreg, and warping can be reduced even in an asymmetric structure. A composite laminate having an improved appearance can be obtained.

[Thermal linear expansion coefficient]
The conductive prepreg of the present invention is characterized in that (1) the cured conductive prepreg has a linear thermal expansion coefficient of 1.0×10 ⁻⁷ /° C. or more and 9.0×10 ⁻⁵ /° C. or less. If the coefficient of linear thermal expansion exceeds 9.0×10 ⁻⁵ /° C., curing shrinkage increases when the resin composition is cured, which may cause warpage or delamination of the pre-greg, and may also reduce physical properties. From the viewpoint of appearance such as electrical conductivity, strength and warpage, the coefficient of linear thermal expansion is preferably 7.0×10 ⁻⁵ /° C. or less, more preferably 5.0×10 ⁻⁵ /° C. or less.
Although the lower limit of the thermal expansion coefficient is not particularly limited, it is usually 1.0×10 ⁻⁷ /° C. or higher.

In order to make the coefficient of thermal expansion within the above range, the type and amount of carbon fiber contained in the prepreg should be appropriately selected, or the type and amount of the compound (C) described later should be appropriately selected. can be done.
In the present invention, the thermal linear expansion coefficient can be measured using a thermomechanical analyzer, and when measured at a temperature range of 23 ° C. (room temperature) to 170 ° C. at a heating rate of 2 ° C./min, the temperature is from 50 ° C. It is calculated from the following formula using the sample length for the coefficient of thermal expansion up to 150°C.
Thermal expansion coefficient = (1/L ₀ ) × [(L ₁₅₀ -L ₅₀ )/(150-50)]
L ₀ : sample length (mm) at 23°C (room temperature), L ₁₅₀ : sample length (mm) at 150°C, L ₅₀ : sample length (mm) at 50°C.
More specifically, the linear thermal expansion coefficient is measured by the method described in Examples below.

[Volume resistivity]
The conductive prepreg of the present invention is characterized in that (2) the volume resistivity of the conductive prepreg after curing is 1.0×10 ⁻⁶ Ω·cm or more and 1.0×10 ⁶ Ω·cm or less. . The volume resistivity is preferably 1.0×10 ⁵ Ω·cm or less, more preferably 1.0×10 ⁰ Ω·cm or less.
If the volume resistivity exceeds 1.0×10 ⁶ Ω·cm, the electrical conductivity is insufficient. Although there is no particular lower limit for the volume resistivity, it is usually 1.0×10 ⁻⁶ Ω·cm or more.
In order to make the volume resistivity of the cured product within the above range, the conductive polymer (A) and the protonic acid dopant (B) should be appropriately selected, their content ratio and dispersibility should be suitable, etc. can be adjusted by

In the present invention, the volume resistivity can be measured using a low resistivity meter in accordance with JIS K 7194:1994. In general, it can be said that a volume resistivity of 1.0×10 ⁰ Ω·cm or less is excellent in conductivity.
More specifically, the volume resistivity is measured by the method described in Examples below.

[Carbon fiber]
Carbon fiber is used as a fiber reinforcing material in the conductive prepreg of the present invention. Carbon fiber is preferred in terms of strength, rigidity, and light weight.
As the fiber reinforcing material, known materials such as glass fiber, aramid fiber, polyethylene terephthalate fiber, vinylon fiber, polyester fiber, amide fiber, and ceramic fiber may be used in combination with carbon fiber. Moreover, the shape of the fiber reinforcing material includes a mat, a cloth, a non-woven fabric, and the like.

Examples of carbon fibers include, but are not limited to, PAN-based carbon fibers, pitch-based carbon fibers, rayon-based carbon fibers, and the like.
Also, the carbon fibers may be sized. The sizing treatment is performed for the purpose of improving the interfacial adhesion between the carbon fibers and the impregnating resin. In the present invention, the carbon fiber sizing treatment agent preferably contains an epoxy resin from the viewpoints of being flexible, easily improving the strength of the carbon fiber, and easily obtaining adhesiveness to the resin composition.
The basis weight of the fiber reinforcing material may be appropriately determined depending on the purpose of use of the conductive prepreg, but it is usually practically 50 g/m ² or more and 2000 g/m ² or less. The basis weight of the fiber reinforcing material is preferably 60 g/m ² or more, more preferably 100 g/m ² or more, from the viewpoint of obtaining a prepreg that is well impregnated with the resin composition. In addition, from the same viewpoint as above, the basis weight of the fiber reinforcing material is preferably 600 g/m ² or less, more preferably 300 g/m ² or less.

[Resin composition]
(Conductive polymer (A))
In the present invention, polyaniline, polyaniline derivatives, polyphenylenevinylene, polythiophene, poly(3,4-dioxythiophene) and the like can be used as the conductive polymer (A). In the present invention, the conductive polymer (A) is preferably polyaniline or polyaniline derivative.
Polyaniline is an insulator in the emeraldine base (EB) state shown in formula (1) below.

When this polyaniline in the EB state is doped with a protonic acid dopant H ⁺ A ⁻ (dissociated state), it forms a salt with the imino group in the polyaniline, resulting in an electronic state exhibiting electrical conductivity represented by the following formula (2). Change to emeraldine salt (ES) state.
The electronic state of polyaniline can be confirmed from the UV-vis-NIR spectrum.

(Proton acid dopant (B))
A protonic acid dopant (B) is used to render the EB state conductive polymer (A) conductive.
As the protonic acid dopant (B) in the present invention, inorganic acids such as hydrochloric acid, sulfuric acid, nitric acid and phosphoric acid; organic acids such as organic sulfonic acid, organic carboxylic acid and organic phosphoric acid can be used. Among them, the protonic acid dopant (B) is preferably an organic sulfonic acid.

When polyaniline is used as the conductive polymer (A), it is preferable to use an organic acid having a site with large steric hindrance as the protonic acid dopant (B).
Specific examples of the organic acid having a site with large steric hindrance include dodecylbenzenesulfonic acid represented by the following formula (3), benzenesulfonic acid, toluenesulfonic acid, polystyrenesulfonic acid, alkylnaphthalenesulfonic acid, and anthraquinonesulfonic acid. , alkylsulfonic acid, dodecylsulfonic acid, camphorsulfonic acid, dioctylsulfosuccinic acid, porphyrin tetrasulfonic acid, polyvinylsulfonic acid and other organic sulfonic acids; propyl phosphate, butyl phosphate, hexyl phosphate, polyethylene oxide dodecyl ether phosphate, polyethylene oxide organic phosphoric acid such as alkyl ether phosphoric acid; Among them, dodecylsulfonic acid, alkylsulfonic acid, dodecylbenzenesulfonic acid, butyl phosphate, and hexyl phosphate are more preferable.

Even if the rigid polyaniline main chain is doped with an inorganic acid dopant such as hydrochloric acid, the polyaniline is insoluble and infusible, resulting in poor workability. On the other hand, when an organic acid having a site with large steric hindrance is used as the dopant, the acidic group functions as a dopant, while the sterically hindered moiety suppresses the interaction between the polyaniline main chains and improves the mobility. By increasing the temperature, good dispersibility with organic chemicals and workability are improved. Therefore, it can be said that such a protonic acid dopant is a functional dopant capable of making polyaniline exhibit electrical conductivity and improving workability.
The protonic acid dopant (B) may be used alone or in combination. For example, in order to adjust the viscosity, it is possible to use both a liquid protonic acid dopant and a solid protonic acid dopant that are compatible with each other.

(Compound (C))
A compound (C) having an alicyclic skeleton and an epoxy group is used as a polymerizable monomer in the present invention.
Compound (C) is a compound having an alicyclic skeleton and one or more epoxy groups, and has at least an alicyclic (aliphatic ring) structure and an epoxy group (oxiranyl group) in its molecule (in one molecule). It is a compound having Specifically, the compound (C) includes (i) a compound having an epoxy group (alicyclic epoxy group) composed of two adjacent carbon atoms and an oxygen atom constituting an alicyclic skeleton, (ii) ) a compound having an epoxy group directly single-bonded to a carbon atom constituting an alicyclic skeleton, (iii) a hydrogenated aromatic glycidyl ether-based epoxy compound, etc., which may be used singly or in a plurality of types. may be used in combination.
In the present invention, the protonic acid dopant (B) acts as a cationic polymerization initiator and no cationic reactive catalyst is used. When the compound (C) is used as a polymerization monomer, the polymerization reaction hardly occurs at room temperature, but the polymerization reaction starts when heat is applied.

As the above (i) compound having an epoxy group composed of two adjacent carbon atoms and an oxygen atom constituting an alicyclic skeleton (hereinafter sometimes referred to as "epoxy compound (i)") can be arbitrarily selected from known or commonly used ones. Among them, the alicyclic epoxy group is preferably a cyclohexene oxide group (an epoxy group composed of two carbon atoms and an oxygen atom that form a cyclohexane ring). Specifically, a compound represented by the following formula (4) (alicyclic epoxy compound) can be mentioned.

In the above formula (4), X represents a monovalent organic group. Examples of the monovalent organic groups include hydrocarbon groups (monovalent hydrocarbon groups), alkoxy groups, alkenyloxy groups, aryloxy groups, aralkyloxy groups, acyloxy groups, alkylthio groups, alkenylthio groups, and arylthio groups. , aralkylthio group, carboxyl group, alkoxycarbonyl group, aryloxycarbonyl group, aralkyloxycarbonyl group, glycidyl group, epoxy group, cyano group, isocyanate group, carbamoyl group, isothiocyanate group, these groups and linking described later A group to which a group (a divalent group having one or more atoms) is bonded, and the like are included.
Examples of the hydrocarbon group include an aliphatic hydrocarbon group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and groups in which two or more of these groups are bonded.
Examples of the aliphatic hydrocarbon group include alkyl groups, alkenyl groups, and alkynyl groups.
Examples of the alkyl group include C1-20 alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, hexyl group, octyl group, isooctyl group, decyl group and dodecyl group.
Examples of the alkenyl group include vinyl group, allyl group, methallyl group, 1-propenyl group, isopropenyl group, 1-butenyl group, 2-butenyl group, 3-butenyl group, 1-pentenyl group and 2-pentenyl group. , 3-pentenyl group, 4-pentenyl group, 5-hexenyl group and other C2-20 alkenyl groups.
Examples of the alkynyl group include C2-20 alkynyl groups such as ethynyl group and propynyl group.

Examples of the alicyclic hydrocarbon group include, for example, a C3-12 cycloalkyl group such as a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, and a cyclododecyl group; a C3-12 cycloalkenyl group such as a cyclohexenyl group; Examples include C4-15 bridged cyclic hydrocarbon groups such as bicycloheptanyl group and bicycloheptenyl group.
Examples of the aromatic hydrocarbon group include C6-14 aryl groups (especially C6-10 aryl groups) such as phenyl group and naphthyl group.
Examples of the group in which the aliphatic hydrocarbon group and the alicyclic hydrocarbon group are bonded together include a cyclohexylmethyl group and a methylcyclohexyl group. Examples of groups in which an aliphatic hydrocarbon group and an aromatic hydrocarbon group are bonded include a C7-18 aralkyl group such as a benzyl group and a phenethyl group, a C6-10 aryl-C2-6 alkenyl group such as a cinnamyl group, and tolyl. C1-4 alkyl-substituted aryl groups such as groups, C2-4 alkenyl-substituted aryl groups such as styryl groups, and the like.

The hydrocarbon group may have a substituent. The number of carbon atoms in the substituent in the hydrocarbon group is not particularly limited, but is preferably 0-20, more preferably 0-10. Examples of the substituent include halogen atoms such as fluorine, chlorine, bromine and iodine atoms; hydroxyl groups; alkoxy groups such as methoxy, ethoxy, propoxy, isopropyloxy, butoxy and isobutyloxy groups. (especially, C1-6 alkoxy group); alkenyloxy group such as allyloxy group (especially, C2-6 alkenyloxy group); phenoxy group, tolyloxy group, naphthyloxy group, etc., C1-4 alkyl group, C2 -4 alkenyl group, halogen atom, aryloxy group optionally having a substituent such as C1-4 alkoxy group (especially C6-14 aryloxy group); aralkyloxy group such as benzyloxy group and phenethyloxy group (especially C7-18 aralkyloxy group); acetyloxy group, propionyloxy group, (meth) acryloyloxy group, acyloxy group such as benzoyloxy group (especially C1-12 acyloxy group); mercapto group; methylthio group, ethylthio Alkylthio groups such as groups (especially C1-6 alkylthio groups); alkenylthio groups such as allylthio groups (especially C2-6 alkenylthio groups); an arylthio group (especially a C6-14 arylthio group) optionally having a substituent such as an alkyl group, a C2-4 alkenyl group, a halogen atom, a C1-4 alkoxy group; an aralkylthio such as a benzylthio group and a phenethylthio group; group (especially C7-18 aralkylthio group); carboxyl group; alkoxycarbonyl group such as methoxycarbonyl group, ethoxycarbonyl group, propoxycarbonyl group, butoxycarbonyl group (especially C1-6 alkoxy-carbonyl group); phenoxycarbonyl group , tolyloxycarbonyl group, aryloxycarbonyl group such as naphthyloxycarbonyl group (especially C6-14 aryloxy-carbonyl group); aralkyloxycarbonyl group such as benzyloxycarbonyl group (especially C7-18 aralkyloxy-carbonyl group ); amino group; mono or dialkylamino group such as methylamino group, ethylamino group, dimethylamino group, diethylamino group (especially mono or di-C1-6 alkylamino group); acetylamino group, propionylamino group, benzoyl acylamino group such as amino group (especially C1-11 acylamino group); epoxy group, glycidyl group, glycidyloxy group, cyclohexene epoxy group-containing groups such as oxide groups; oxetanyl group-containing groups such as ethyloxetanyloxy groups; acyl groups such as acetyl groups, propionyl groups and benzoyl groups; oxo groups; and groups bonded via.

Among the compounds represented by the above formula (4), compounds represented by the following formula (4-1) (alicyclic epoxy compounds) are particularly preferred from the viewpoint of the heat resistance and light resistance of the cured product.

In formula (4-1) above, Y represents a single bond or a linking group (a divalent group having one or more atoms).
Examples of the linking group include a divalent hydrocarbon group, a carbonyl group, an ether bond, an ester bond, a carbonate group, an amide group, and groups in which a plurality of these are linked.
Alicyclic epoxy compounds in which Y in formula (4-1) is a single bond include 3,4,3′,4′-diepoxybicyclohexane and the like.

Examples of the divalent hydrocarbon group include linear or branched alkylene groups having 1 to 18 carbon atoms, divalent alicyclic hydrocarbon groups, and the like. Examples of linear or branched alkylene groups having 1 to 18 carbon atoms include methylene group, methylmethylene group, dimethylmethylene group, ethylene group, propylene group and trimethylene group. Examples of divalent alicyclic hydrocarbon groups include 1,2-cyclopentylene group, 1,3-cyclopentylene group, cyclopentylidene group, 1,2-cyclohexylene group, 1,3-cyclohexylene group, Divalent cycloalkylene groups (including cycloalkylidene groups) such as silene group, 1,4-cyclohexylene group, cyclohexylidene group, and the like can be mentioned.
As the linking group Y, a linking group containing an oxygen atom is particularly preferable, and specifically, for example, -CO-, -O-CO-O-, -COO-, -O-, -CONH-; groups in which a plurality of these groups are linked; groups in which one or more of these groups are linked to one or more of divalent hydrocarbon groups; Examples of the divalent hydrocarbon group include those exemplified above.

Representative examples of the compound represented by the above formula (4-1) include compounds represented by the following formulas (I-1) to (I-10), bis(3,4-epoxycyclohexylmethyl) ether , 1,2-bis(3,4-epoxycyclohexan-1-yl)ethane, 1,2-epoxy-1,2-bis(3,4-epoxycyclohexan-1-yl)ethane, 2,2-bis (3,4-epoxycyclohexan-1-yl)propane and the like.
Note that l and m in the following formulas (I-5) and (I-7) each represent an integer of 1 to 30. R in the following formula (I-5) is an alkylene group having 1 to 8 carbon atoms, and is a methylene group, ethylene group, propylene group, isopropylene group, butylene group, isobutylene group, s-butylene group, pentylene group, hexylene. linear or branched alkylene groups such as radicals, heptylene groups, and octylene groups. Among these, straight-chain or branched-chain alkylene groups having 1 to 3 carbon atoms such as methylene, ethylene, propylene and isopropylene are preferred. n1 to n6 in the following formulas (I-9) and (I-10) each represent an integer of 1 to 30.

Examples of the alicyclic epoxy compounds represented by the above formulas (I-1) to (I-10) include commercially available products such as trade names "Celoxide 2021P" and "Celoxide 2081" (manufactured by Daicel Corporation). You can also use the product.

Examples of (ii) a compound having an epoxy group directly single-bonded to a carbon atom constituting an alicyclic skeleton (hereinafter sometimes referred to as "epoxy compound (ii)") include the following: A compound represented by the formula (II) and the like can be mentioned.

In formula (II), R ' is a group (p-valent organic group) obtained by removing p hydroxyl groups (-OH) from a p-valent alcohol in the structural formula, and p and n each represent a natural number. . Examples of the p-valent alcohol [R'(OH) _p ] include polyhydric alcohols (such as alcohols having 1 to 15 carbon atoms) such as 2,2-bis(hydroxymethyl)-1-butanol. p is preferably 1-6, and n is preferably 1-30. When p is 2 or more, n in each group in parentheses (outer parentheses) may be the same or different.
Specific examples of the compound represented by formula (II) include a 1,2-epoxy-4-(2-oxiranyl)cyclohexane adduct of 2,2-bis(hydroxymethyl)-1-butanol [for example, , trade name “EHPE3150” (manufactured by Daicel Corporation), etc.] and the like.

The (iii) hydrogenated aromatic glycidyl ether epoxy compound (hereinafter sometimes referred to as "epoxy compound (iii)") includes, for example, 2,2-bis[4-(2,3-epoxypropoxy ) Cyclohexyl]propane, 2,2-bis[3,5-dimethyl-4-(2,3-epoxypropoxy)cyclohexyl]propane, bisphenol A type such as compounds represented by the following formula (III) Compounds obtained by hydrogenating epoxy compounds (nuclear hydrogenated bisphenol A type epoxy compounds); bis[o,o-(2,3-epoxypropoxy)cyclohexyl]methane, bis[o,p-(2,3-epoxy) propoxy)cyclohexyl]methane, bis[p,p-(2,3-epoxypropoxy)cyclohexyl]methane, bis[3,5-dimethyl-4-(2,3-epoxypropoxy)cyclohexyl] Compounds obtained by hydrogenating bisphenol F type epoxy compounds such as methane (nuclear hydrogenated bisphenol F type epoxy compounds); hydrogenated biphenol type epoxy compounds; hydrogenated phenol novolac type epoxy compounds; hydrogenated cresol novolac type epoxy compounds; hydrogenated epoxy compounds of cresol novolac type epoxy compounds; hydrogenated naphthalene type epoxy compounds; and hydrogenated epoxy compounds of epoxy compounds obtained from trisphenolmethane.
As the compound represented by the following formula (III), specifically, trade name "YX8000" (manufactured by Mitsubishi Chemical Corporation), trade name "YX8034" (manufactured by Mitsubishi Chemical Corporation), and the like can be used.

In formula (III), q represents an integer of 1 or more (eg, an integer of 1 to 5).

The epoxy compound (i), epoxy compound (ii), and epoxy compound (iii) may be used alone or in combination.

The compound (C) preferably has a weight average molecular weight in the range of 200-2000. Further, the weight average molecular weight of the compound (C) is more preferably 200-1000, more preferably 200-500, from the viewpoint of easy preparation of the resin composition.

(Content ratio)
In the resin composition, the content of the compound (C) is preferably 5% by mass or more, more preferably 10% by mass or more, in consideration of compatibility between conductivity and moldability. The content of the compound (C) in the resin composition is preferably 45% by mass or less, more preferably 40% by mass or less, from the same viewpoint as above.
In the above resin composition, when the conductive polymer (A) is polyaniline, the nitrogen atoms of polyaniline and the protonic acid dopant (B) are preferably in a molar ratio [nitrogen atoms of polyaniline: protonic acid dopant] 10:1 to 1:2.
If the amount of the protonic acid dopant (B) is too small, the polymerization/curing reaction will not proceed sufficiently even when heated, and the state of polyaniline will change from the ES state to the EB state, resulting in loss of electrical conductivity. On the other hand, if the amount of the protonic acid dopant (B) exceeds this range, it becomes difficult to form a conductive path with polyaniline, resulting in poor electrical conductivity, and an exothermic reaction starts at room temperature without heating. , it becomes difficult to control the reaction, resulting in rapid curing.

Further, in the resin composition, the total of the conductive polymer (A) and the protonic acid dopant (B) and the compound (C) have a mass ratio [total of the conductive polymer (A) and the protonic acid dopant (B) : Compound (C)], preferably 1:1 to 1:0.1, more preferably 1:1 to 1:0.3.
The greater the total amount of the conductive polymer (A) and the protonic acid dopant (B), the higher the electrical conductivity of the resin composition. Further, within the range of the above mass ratio, the composite of the conductive polymer (A) and the protonic acid dopant (B) is preferably dispersed in the resin composition, and excellent conductivity is likely to be exhibited.
Also, the total amount of the conductive polymer (A) and the protonic acid dopant (B) in the resin composition is preferably 20-60% by mass, more preferably 30-50% by mass. If the total mass % of the conductive polymer (A) and the protonic acid dopant (B) in the resin composition is within the above range, the prepreg can be imparted with superior electrical conductivity.

(Epoxy compound (D) other than compound (C))
In order to improve low viscosity and storage stability, the resin composition in the present invention contains the compound (C) and an epoxy compound other than the compound (C) (hereinafter referred to as "another epoxy compound (D)"). Yes.) are used together.
Examples of the other epoxy compounds (D) include aromatic glycidyl ether-based epoxy compounds [e.g., bisphenol A-type epoxy compounds, bisphenol F-type epoxy compounds, biphenol-type epoxy compounds, phenol novolac-type epoxy compounds, cresol novolak-type epoxy compounds, compounds, bisphenol A cresol novolak-type epoxy compounds, naphthalene-type epoxy compounds, epoxy compounds obtained from trisphenolmethane, etc.], aliphatic glycidyl ether-based epoxy compounds [e.g., aliphatic polyglycidyl ethers, etc.], glycidyl ester-based epoxy compounds , glycidylamine-based epoxy compounds, and isocyanurate compounds having an epoxy group [eg, diallyl monoglycidyl isocyanurate compounds, monoallyl diglycidyl isocyanurate compounds, triglycidyl isocyanurate compounds, etc.].
Among others, the other epoxy compound (D) preferably has an aromatic skeleton. Moreover, you may use the said other epoxy compound (D) individually or in combination of multiple types.
The content of the other epoxy compound (D) is not particularly limited, but is usually about 1 to 30% by mass in the resin composition, and can be added in an appropriate ratio according to the viscosity of the resin composition.

[Curing agent (E)]
The resin composition in the present invention contains a curing agent (E) in order to sufficiently cure the other epoxy compound (D).
As the curing agent (E), known or commonly used curing agents can be used as curing agents for epoxy resins, and are not particularly limited. amine curing agents), polyamide resins, imidazoles (imidazole curing agents), polymercaptans (polymercaptan curing agents), phenols (phenolic curing agents), polycarboxylic acids, dicyandiamides, organic acid hydrazides, etc. mentioned. The curing agent (E) may be used alone or in combination.
Although the content of the curing agent (E) is not particularly limited, it is usually about 1 to 20% by mass in the resin composition, and can be added in an appropriate ratio according to the viscosity of the resin composition.

[Curing accelerator (F)]
A curing accelerator (F) can be further contained in order to accelerate the curing of the resin composition in the present invention.
The curing accelerator (F) is a compound that has the function of accelerating the reaction rate when the other epoxy compound (D) reacts with the curing agent (E).
As the curing accelerator (F), a known or commonly used curing accelerator can be used, and is not particularly limited. , phenol salt, octylate, p-toluenesulfonate, formate, tetraphenylborate salt, etc.); 1,5-diazabicyclo[4.3.0]nonene-5 (DBN) or a salt thereof (for example, phenol salt, octylate, p-toluenesulfonate, formate, tetraphenylborate salt, etc.); benzyldimethylamine, 2,4,6-tris(dimethylaminomethyl)phenol, N,N-dimethylcyclohexylamine, etc. tertiary amines; imidazoles such as 2-ethyl-4-methylimidazole and 1-cyanoethyl-2-ethyl-4-methylimidazole; phosphoric acid esters; phosphines such as triphenylphosphine and tris(dimethoxy)phosphine; tetraphenylphosphonium phosphonium compounds such as tetra(p-tolyl)borate; organic metal salts such as zinc octylate, tin octylate and zinc stearate; and metal chelates such as aluminum acetylacetone complexes. The curing accelerator (F) may be used alone or in combination.

As the curing accelerator (F), trade names "U-CAT SA 506", "U-CAT SA 102", "U-CAT5003", "U-CAT18X", "U-CAT12XD" (developed products) (above , manufactured by San-Apro Co., Ltd.); trade names "TPP-K" and "TPP-MK" (manufactured by Hokko Chemical Industry Co., Ltd.); trade name "PX-4ET" (manufactured by Nippon Chemical Industry Co., Ltd.), etc. can also be used.
The content of the curing accelerator (F) is not particularly limited, but it is usually about 0.1 to 5% by mass in the resin composition, and can be added in an appropriate ratio according to the viscosity of the resin composition. .

[Other components (additives)]
One or more resins selected from the group consisting of thermoplastic resins, thermoplastic elastomers and elastomers can be added as additives to the resin composition used in the present invention. This additive has the role of improving the toughness of the matrix resin and changing the viscoelasticity to optimize the viscosity, storage modulus and thixotropic properties. The thermoplastic resins, thermoplastic elastomers or elastomers used as additives may be used alone or in combination.

As the thermoplastic resin, a group consisting of a carbon-carbon bond, an amide bond, an imide bond, an ester bond, an ether bond, a carbonate bond, a urethane bond, a urea bond, a thioether bond, a sulfone bond, an imidazole bond and a carbonyl bond in the main chain. A thermoplastic resin having a bond selected from is preferably used.
Among them, a group of thermoplastic resins belonging to engineering plastics such as polyacrylate, nylon, polyaramid, polyester, polycarbonate, polyphenylene sulfide, polybenzimidazole, polyimide, polyetherimide, polysulfone and polyethersulfone are more preferably used.
Polyimide, polyetherimide, polysulfone, polyethersulfone and the like are particularly preferably used because of their excellent heat resistance. Among these, polyethersulfone is more preferable because it can increase the toughness while maintaining the heat resistance and elastic modulus of the cured product.
In addition, it is preferable that these thermoplastic resins have a functional group reactive with the thermosetting resin from the viewpoint of improving the 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.

(Method for producing resin composition)
The resin composition is prepared by mixing the conductive polymer (A) and the protonic acid dopant (B), dispersing the conductive polymer (A) in the protonic acid dopant (B), After forming a complex of the acid dopant (B), the complex can be produced by mixing and dispersing the complex with compounds (C) to (E) and optionally (F) and other components.
The apparatus used for the above mixing is not particularly limited, and examples include ball mills, bead mills, planetary ball mills, vibrating ball mills, sand mills, colloid mills, attritors, roll mills, high-speed impeller dispersion, dispersers, homogenizers, high-speed impact mills, and ultrasonic waves. Dispersion, mechanical stirring using stirring blades and the like can be mentioned.

[Method for producing conductive prepreg]
The conductive prepreg of the present invention is a conductive prepreg obtained by impregnating a fiber reinforcing material containing carbon fibers with the resin composition described above, and can be produced by a known method such as a wet method or a hot melt method.
For example, a resin obtained by applying the above-mentioned resin composition as a matrix resin to a sheet such as a resin film, aluminum foil, and release paper on the upper and lower sides of a fiber reinforcing material in which continuous carbon fibers are arranged in one direction or is woven. The conductive prepreg of the present invention can be produced by coating with a sheet and incorporating the resin composition into the fiber reinforcing material.

In the conductive prepreg of the present invention, the amount of the resin composition attached to the fiber reinforcing material containing carbon fibers is usually 20 to 90% by mass, preferably 25 to 55% by mass, in terms of the resin content of the conductive prepreg after drying. The resin composition may be applied to the fiber reinforcing material so that

<Composite material>
The present invention provides a cured composite comprising the aforementioned electrically conductive prepreg. The composite material is obtained by using a single layer or a plurality of layers (two or more layers) of the conductive prepreg described above, and curing the resin composition by heating while applying pressure.
The method of heating and curing the prepreg while applying pressure may be any of press molding, autoclave molding, bagging molding, wrapping tape, and internal pressure molding, and may be selected according to the application.
The pressure at the time of pressing can be usually about 0.1 to 2 MPa. If the pressure is within this range, problems such as voids do not occur, and physical properties of the conductive prepreg of the present invention, such as strength and conductivity, are not impaired.
Moreover, the above heating can be carried out usually at about 100 to 250.degree. Within this temperature range, there is no side reaction due to oxygen or the like, or problems with moldability such as cracks, and there is no fear that the physical properties of the conductive prepreg of the present invention, such as strength and conductivity, will be impaired.
Since the conductive prepreg described above uses both the compound (C) having an alicyclic skeleton and an epoxy group and the epoxy compound (D) other than the compound (C), the adhesion between the carbon fiber and the resin composition is improved. become good. In addition, since the resin composition undergoes less curing shrinkage even when cured, a composite material having both lightness and strength while having excellent conductivity can be obtained. In the case of multiple layers, it is possible to improve the interfacial strength between the layers.

<Composite laminate>
The present invention also provides a laminate having the composite material described above and a composite material other than the composite material, wherein at least one layer of the composite material described above is provided on at least one surface of the laminate. provide the body
Composite materials other than the above-described composite materials (hereinafter sometimes referred to as "other composite materials") constituting the composite laminate are not particularly limited and may be appropriately selected within a range that does not impair the effects of the present invention. Although it can be used, it is preferable to use a prepreg containing carbon fibers other than the conductive prepreg of the present invention from the viewpoint of the conductivity, strength, lightness, etc. of the composite laminate. Alternatively, the other composite material may be a commercially available carbon fiber prepreg.

The composite material laminate can be a laminate having high conductivity by having the aforementioned composite material on at least one surface.
That is, the composite material laminate should have at least one layer of the above-described composite material on one surface. Further, when the composite material described above is A and the other composite material is B, the layer structure may be AB, ABB, AABB, AABBB, AAABB, AABBBB, or the like.
Furthermore, the composite material laminate may have the composite material described above on both sides, and may have a layer structure such as ABA, ABBA, AABBBA, or the like.

The composite laminate of the present invention can be produced by laminating the above-mentioned conductive prepreg before curing and another prepreg before curing and then curing (batch lamination curing). In addition, after laminating the above-mentioned conductive prepreg before curing and another composite material after curing, the above-mentioned conductive prepreg may be cured and integrated to manufacture. After laminating another prepreg, the other prepreg may be cured and integrated.
The conditions such as pressure and heating for manufacturing the composite material laminate are the same as those in the method for manufacturing the composite material described above.

When a prepreg impregnated with a conventional cation-reactive matrix resin is laminated with another prepreg, curing does not proceed well at the interface between the prepregs, resulting in a laminate with poor interfacial strength. . In addition, the prepreg impregnated with the above-described conventional cation-reactive matrix resin has a risk of curing shrinkage due to curing, warping of the laminate, impairing the appearance, and deterioration of physical properties due to this.
On the other hand, the composite material laminate of the present invention is a prepreg made of a resin composition containing a fiber reinforcing material in which the composite material is carbon fiber and made of an epoxy compound, and has a base structure similar to that of other carbon fiber-containing prepregs. Therefore, the thermal linear expansion coefficients of the cured products are very close to each other. Therefore, the composite material laminate of the present invention can be collectively laminated and cured even as a laminate having an asymmetric structure of the above-described composite material and a commercially available prepreg, and exhibits the performance of the above-described conductive prepreg of the present invention. In addition, warpage can be reduced, and an effect of improving appearance can also be obtained. In addition, the composite laminate can exhibit an effect of being excellent in interfacial strength.

<Application>
The conductive prepreg of the present invention has excellent conductivity, and the composite material and the composite material laminate have the excellent conductivity of the conductive prepreg, while the warpage is reduced and the appearance is improved. Therefore, it is useful for applications such as aviation members such as main wings, tail wings, and fuselages, vehicles such as automobiles, motorcycles, and railways, housings for electronic devices, semiconductor packages, and printed wiring boards for electronic devices.
That is, the present invention can also provide an aeronautical member or the like comprising either one or both of the aforementioned composite or composite laminate.

EXAMPLES The present invention will be specifically described below with reference to Examples and Comparative Examples, but the present invention is not limited to these.

(C) to (F) used in the production examples are as follows.
・(C): Celoxide 2021P: Product name “Celoxide 2021P” [3,4-epoxycyclohexylmethyl (3,4-epoxy) cyclohexane carboxylate], molecular weight 252, manufactured by Daicel Corporation ・(C): YX8000: Product Name “YX8000” [nuclear hydrogenated bisphenol A type epoxy compound], molecular weight >200, manufactured by Mitsubishi Chemical Corporation ・(D): jER630: trade name “jER630” [polyfunctional glycidylamine type epoxy compound], molecular weight 130 , Mitsubishi Chemical Co., Ltd. (E): YH306: trade name “JER Cure YH306” [acid anhydride], Mitsubishi Chemical Co., Ltd. (F): U-CAT SA102: [DBU-octylate] , manufactured by San-Apro Co., Ltd.

<Production of resin composition>
A resin composition used in Examples or Comparative Examples was produced by the following method.
[Production Example 1]
(1) Preparation of polyaniline A-dodecylbenzenesulfonic acid complex (mixture of conductive polymer (A) and protonic acid dopant (B))
30 parts of commercially available polyaniline (PANI) in the form of emeraldine base (EB) and 70 parts of dodecylbenzenesulfonic acid (DBSA) are blended and kneaded with a three-roll mill so as to uniformly disperse the paste. A mixture (polyaniline A-dodecylbenzenesulfonic acid complex) was obtained.
(2) Production of Resin Composition I To 4 g of the above polyaniline A-dodecylbenzenesulfonic acid complex, 2 g of an alicyclic epoxy compound (compound (C), YX8000, equivalent to the above epoxy compound (iii)) is added, In addition, for viscosity adjustment, 2.46 g of a multifunctional epoxy resin JER630 as another epoxy compound (D), 1.54 g of an acid anhydride curing agent YH306 as a curing agent (E), and a curing accelerator (F). 0.06 g of DBU-octylic acid U-CAT SA102 was added as a mixture and stirred at room temperature using a rotation/revolution mixer to obtain a well-dispersed creamy resin composition I.

[Production Example 2]
Production of Resin Composition II To 4 g of the polyaniline A-dodecylbenzenesulfonic acid composite prepared in (1) of Production Example 1 above, 6 g of divinylbenzene was added and stirred at room temperature for 20 minutes using a rotation-revolution mixer. A pasty resin composition II in which the polyaniline A-dodecylbenzenesulfonic acid complex was well dispersed was obtained.
[Production Example 3]
Production of Resin Composition III Production except that in (2) of Production Example 1 above, Celoxide 2021P (corresponding to epoxy compound (i) described above) was used instead of YX8000 as the alicyclic epoxy of compound (C). A resin composition III was obtained in the same manner as in Example 1.

<Production of conductive prepreg and composite material>
[Example 1]
The basis weight of the film is set so that the resin content of the conductive prepreg when two films are used is 42% by mass, and the resin composition I is applied to the film (release paper) using a film coater. to obtain a resin film.
The above resin film is attached to both sides of carbon fibers (TR3110M4, plain weave, manufactured by Mitsubishi Chemical Corporation) having a fiber basis weight of 200 g/m ² and nipped, and the fiber basis weight is 200 g/m ² and the resin content is 40% by mass. of conductive prepreg (i) was obtained.
This conductive prepreg (i) was heated and pressed in a vacuum press at 120° C. and a pressure of 0.7 MPa for 2 hours to obtain a cured sheet of conductive prepreg, that is, a composite material.

[Comparative Example 1]
In Example 1, the resin composition II was used in place of the resin composition I, and in the same manner as in Example 1, a conductive prepreg (ii) and a cured composite were obtained.
[Example 2]
In Example 1, the resin composition III was used in place of the resin composition I, and in the same manner as in Example 1, a conductive prepreg (iii) and a cured composite were obtained.

[Characteristic evaluation of composite material]
The cured sheets (composite materials) of the conductive prepregs obtained in Examples 1 and 2 and Comparative Example 1 were measured for volume resistivity and thermal linear expansion coefficient by the following methods. Table 2 shows the evaluation results.
(1) Volume resistivity (conductivity)
A sample for measurement (100 mm × 100 mm × 200 μm) was prepared using the cured conductive prepreg sheet obtained in each example, and a resistivity meter “Loresta GP” (Loresta GPMCP-T610 type resistivity meter, JIS K 7194: 1994 compliant, 4-terminal, 4-probe method, constant current application method, manufactured by Mitsubishi Chemical Analytic Tech.
In this example, the smaller the numerical value, the better the conductivity.
(2) Coefficient of linear thermal expansion A sample for measurement (20 mm × 3 mm) was prepared using the cured conductive prepreg sheet obtained in each example, and a thermomechanical analyzer [TMA / SS6100L (Hitachi High Tech Co., Ltd.) (manufactured by Science Co., Ltd.)] at a temperature range of 23° C. (room temperature) to 170° C. at a heating rate of 2° C./min.
From the obtained measurement results, the linear thermal expansion coefficient at 50 to 150° C. was calculated according to the following formula. L ₀ : sample length (mm) at 23°C (room temperature), L ₁₅₀ : sample length (mm) at 150°C, L ₅₀ : sample length (mm) at 50°C.
Thermal expansion coefficient = (1/L ₀ ) × [(L ₁₅₀ -L ₅₀ )/(150-50)]

<Composite laminate>
[Example 3]
The conductive prepreg (i) obtained in Example 1 was laminated as AABBB using 2Ply (AA) and a commercially available prepreg (TR3110381GMX, uncured state, manufactured by Mitsubishi Chemical Corporation) with 3Ply (BBB). , a vacuum press at 120° C., a pressure of 0.7 MPa, and heating and pressing for 2 hours to obtain a cured single-sided highly conductive composite laminate having a thickness of 1 mm.
[Comparative Example 2]
A cured single-sided highly conductive composite laminate was obtained in the same manner as in Example 3, except that the conductive prepreg (i) used in Example 3 was changed to the conductive prepreg (ii) obtained in Comparative Example 1. rice field.
[Comparative Example 3]
Using 2Ply (AA) of the conductive prepreg (ii) obtained in Comparative Example 1, a cured composite material was obtained by heating and pressing in a vacuum press at 120° C. and a pressure of 0.7 MPa for 2 hours. . Next, a commercially available prepreg (manufactured by Mitsubishi Chemical Corporation, TR3110381GMX, uncured state) was laminated on one side of the obtained composite material in the manner of AABBB using 3Ply (BBB), and vacuum pressed at 120 ° C. A pressure of 0.7 MPa, heating and pressing for 2 hours yielded a cured single-sided highly conductive composite laminate with a thickness of 1 mm.

[Characteristic evaluation of composite laminate]
The composite material laminates obtained in Example 3 and Comparative Examples 2 and 3 were evaluated for bending strength and appearance (warpage) by the following methods. Table 3 shows the evaluation results.
(3) Bending strength (MPa)
A bending test (three-point bending) was performed according to JIS K 7074:1988 "Bending test method for carbon fiber reinforced plastics". A rectangular sample with a length of 100 mm and a width of 15 mm was cut out and tested with a span length (distance between lower supports) of 80 mm using a universal testing machine (manufactured by Shimadzu Corporation). However, Comparative Example 3 was not measured.
In this example, the larger the numerical value, the better the interfacial strength.
(4) Appearance condition (warp)
A 25 cm x 25 cm x 1 mm square composite material laminate obtained in each example was cut out and placed on a flat plate. However, Comparative Example 2 was not measured.
○: When the height is less than 0.5 mm ×: When the height is 0.5 mm or more

In Example 3, a laminate using two layers of the conductive prepreg of the present invention and three layers of commercially available prepregs was collectively laminated and cured, and even as a composite laminate, sufficient bending strength was exhibited and the interface strength was improved. In addition, the cured state was good with no warpage.
On the other hand, in Comparative Example 2, the surface of the AA layer using the conductive prepreg (ii) was sticky even after being laminated together and heated, and it was determined that the A layer portion was uncured. Since the layer A portion was sticky, the bending strength of the composite material laminate of Comparative Example 2 was inferior. In Comparative Example 3 in which the AA layer and the BBB layer were each cured, warpage occurred and there was a problem with the appearance.

The prepreg and composite material laminate of the present invention, due to their properties, can be used for aviation members such as main wings, tail wings, and fuselages, vehicles such as automobiles, motorcycles, and railways, housings for electronic devices, semiconductor packages, and printed wiring for electronic devices. It is useful for applications such as boards.

Claims (10)

A sheet-like prepreg that satisfies the following (1) and (2) and contains carbon fibers and a resin composition,
The resin composition comprises a conductive polymer (A), a protonic acid dopant (B), a compound (C) having an alicyclic skeleton and an epoxy group, an epoxy compound (D) other than the compound (C), and curing. Contains agent (E)death,
The mass ratio of the sum of the conductive polymer (A) and the protonic acid dopant (B) to the compound (C) is 1:1 to 1:0.3, and the conductive polymer (A ) and the protonic acid dopant (B) is 20 to 60% by mass in the resin composition,
The conductive polymer (A) is polyaniline or a polyaniline derivative conductive prepreg.
(1) The thermal linear expansion coefficient of the conductive prepreg after curing is 1.0 × 10^-7/ °C or more 9.0 × 10^-5/°C or less
(2) The volume resistivity of the conductive prepreg after curing is 1.0 × 10^-6Ω・cm or more 1.0×10⁶Ω・cm or less 2. The conductive prepreg according to claim 1 , wherein the molar ratio of nitrogen atoms of said polyaniline and said protonic acid dopant (B) is 10:1 to 1:2. 3. The conductive prepreg according to claim 1 or 2 , wherein said protonic acid dopant (B) is an organic sulfonic acid. The compound (C) is (i) a compound having an epoxy group composed of two adjacent carbon atoms and an oxygen atom that constitute an alicyclic skeleton, and (ii) a compound that constitutes an alicyclic skeleton. 4. Conductive according to any one of claims 1 to 3 , which is at least one selected from a compound having an epoxy group directly single-bonded to a carbon atom and (iii) a hydrogenated aromatic glycidyl ether epoxy compound. prepreg. The epoxy compound (D) is selected from the group consisting of aromatic glycidyl ether-based epoxy compounds, aliphatic glycidyl ether-based epoxy compounds, glycidyl ester-based epoxy compounds, glycidylamine-based epoxy compounds, and isocyanurate compounds having an epoxy group. The conductive prepreg according to any one of claims 1 to 4, which is one or more. The conductive prepreg according to any one of claims 1 to 5 , wherein said epoxy compound (D) has an aromatic skeleton. The conductive prepreg according to any one of claims 1 to 6, wherein the content of said epoxy compound (D) is 1 to 30% by mass. A cured composite comprising the electrically conductive prepreg of any one of claims 1-7. A laminate comprising the composite material according to claim 8 and a composite material other than the composite material, wherein at least one layer of the composite material according to claim 8 is provided on at least one surface of the laminate. Composite laminate. An aeronautical component comprising either or both of the composite of claim 8 or the composite laminate of claim 9.