JP2019178298A - Thermosetting conductive composition - Google Patents

Abstract

To provide a thermosetting resin composition capable of giving a cured product excellent in storage stability and excellent in conductivity, moldability, and wettability.SOLUTION: A thermosetting conductive composition contains a conductive polymer (A), a protonic acid dopant (B), and a compound (C) having an alicyclic skeleton and an epoxy group and satisfies the following (1) and (2): (1) the thermosetting conductive composition has a curing reaction initiation temperature of 70°C or higher as measured using a differential scanning calorimeter; and (2) a cured product after curing has a volume resistivity of 1.0×10Ω cm or more and 1.0×10Ω cm or less.SELECTED DRAWING: None

Description

  The present invention relates to a thermosetting conductive composition.

As a lightweight member for aerospace equipment, industry, and mobility, a fiber-reinforced composite member having high conductivity is required.
As a conventional technique related to a fiber-reinforced composite member having high conductivity, for example, a fiber-reinforced composite member that adds inorganic conductive particles and conductive filler to a base material resin containing at least an epoxy resin to impart conductivity to the resin. A resin composition technique has been proposed (Patent Document 1). On the other hand, avoiding the use of conductive filler, a thermosetting conductive resin composition in which a conductive polymer dopant having good conductivity in a doped form is mixed with a monomer having a cationic reactive group such as a styrene derivative Products have been developed (Patent Document 2).

JP 2009-74075 A Japanese Patent Laying-Open No. 2015-10202

However, in the technique described in Patent Document 1, the conductivity of the resin is greatly affected by the amount of conductive filler added and the degree of dispersion.
Moreover, although the hardened | cured material of the conductive resin composition of patent document 2 shows the outstanding electroconductivity, even if it is during the preservation | save of the composition before hardening, there exists a possibility that the reaction of a monomer may occur. There is a problem of poor storage stability. In addition, when the amount of the conductive resin added is increased in order to increase the conductivity, there is a problem that the composition becomes highly viscous and the moldability and curability disappear due to the decrease in the curing component. . That is, the lack of moldability is a problem for industrial development.

  Then, this invention makes it a subject to provide the thermosetting resin composition which can obtain the hardened | cured material which is excellent in storage stability and excellent in electroconductivity, a moldability, and wettability.

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

That is, the present invention includes a conductive polymer (A), a protonic acid dopant (B), and a compound (C) having an alicyclic skeleton and an epoxy group, and satisfying the following (1) and (2). The present invention relates to a conductive composition.
(1) The curing reaction start temperature of the thermosetting conductive composition measured with a differential scanning calorimeter is 70 ° C. or higher. (2) The volume resistivity of the cured product after curing is 1.0 × 10 ^{−. 4} Ω · cm or more and 1.0 × 10 ⁴ Ω · cm or less

  ADVANTAGE OF THE INVENTION According to this invention, the thermosetting resin composition which can obtain the hardened | cured material which is excellent in storage stability and excellent in electroconductivity, a moldability, and wettability can be provided.

<Thermosetting conductive composition>
The thermosetting conductive composition of the present invention includes a conductive polymer (A), a protonic acid dopant (B), and a compound (C) having an alicyclic skeleton and an epoxy group, and the following (1) and ( 2) is satisfied.
(1) The curing reaction start temperature of the thermosetting conductive composition measured with a differential scanning calorimeter is 70 ° C. or higher. (2) The volume resistivity of the cured product after curing is 1.0 × 10 ^{−. 4} Ω · cm or more and 1.0 × 10 ⁴ Ω · cm or less In the thermosetting conductive composition of the present invention (hereinafter sometimes simply referred to as “composition”), the protonic acid dopant (B) is Initiation of polymerization of compound (C) (hereinafter sometimes simply referred to as “compound (C)”) which acts as a dopant component of conductive polymer (A) and has an alicyclic skeleton as a monomer and an epoxy group. Also works as an agent. The conductive polymer (A) is uniformly dispersed in the protonic acid dopant (B), and the conductive polymer uniformly dispersed in the composition by suitably adjusting the content ratio of each component ( Due to the composite consisting of A) and the protonic acid dopant (B), the cured product of the composition has excellent electrical conductivity.

Further, by using the compound (C) as a monomer, the polymerization reaction of the monomer hardly occurs even while the composition before curing is stored, and the effect of excellent storage stability of the composition is exhibited. be able to. The compound (C) has a cycloaliphatic skeleton epoxy group, a high weight average molecular weight, and a complicated steric structure. When a compound having such a structure undergoes a polymerization reaction, it is considered that an effect of significantly reducing the reaction rate of cationic polymerization occurs due to obstacles such as a side chain and a three-dimensional structure. Moreover, since the oxygen of the epoxy group in the compound (C) becomes negatively charged and approaches the protonic acid dopant (B) having a positive ion, the negative oxygen and the positive carbon are bonded and polymerized, so that a chain reaction occurs. It is thought that the change in the binding energy is small and does not lead to a temperature rise. For the above reason, it is considered that the polymerization reaction of the monomer hardly occurs at about room temperature by using the compound (C).
Furthermore, the composition of the present invention has almost no fear of increasing the viscosity or reducing the curing component, and is excellent in moldability since it has good curability. Moreover, the composition of this invention is excellent also in wettability by containing the compound (C) which has an alicyclic skeleton and an epoxy group.

[Curing reaction start temperature]
The composition of the present invention is characterized in that (1) the curing reaction start temperature of the composition measured by using a differential scanning calorimeter is 70 ° C. or higher. The curing reaction start temperature is preferably 80 ° C. or higher, more preferably 100 ° C. or higher. Although there is no restriction | limiting in particular in an upper limit, Usually, it is 200 degrees C or less.
Since the composition of the present invention has thermosetting properties, the curing reaction starts when the temperature rises. If the curing reaction initiation temperature of the composition is less than 70 ° C., which is obtained by measurement with a differential scanning calorimeter (DSC), there is a possibility that the polymerization reaction of the composition occurs before the temperature rise, and exhibits excellent storage stability. Can not do it. Since the composition of the present invention is excellent in storage stability, the uncured state is maintained even during storage. Therefore, for example, even when the composition of the present invention that has been stored is used as a material for various uses such as prepreg, paint, and electronic member, the polymerization reaction of the composition has progressed during the storage period. There is no risk of quality defects, and sufficient practical physical properties of the cured product can be obtained. Moreover, if it is a composition of this invention, it does not need to use for various uses immediately after manufacture of a composition, and it is suitable also for productivity.
In the present invention, it is important to use the compound (C) as a monomer in order to make the curing reaction start temperature within a desired range, and in addition, the content ratio and dispersibility of each component are suitably adjusted. Can be achieved.

In the present invention, the curing reaction start temperature is the temperature at which the curing reaction peak rises by DSC measurement, and is determined by the intersection of the tangent of the inflection point of the exothermic curve obtained by DSC and the tangent of the baseline. In general, the higher the peak temperature, the more likely the curing reaction does not start at room temperature. When the curing reaction starting temperature is 70 ° C. or higher, the storage stability of the composition is excellent.
More specifically, the curing reaction start temperature is measured by the method described in Examples described later.

[Volume resistivity of cured product]
The composition of the present invention is characterized in that (2) the volume resistivity of the cured product after curing is 1.0 × 10 ⁻⁴ Ω · cm or more and 1.0 × 10 ⁴ Ω · cm or less. The volume resistivity is preferably 1.0 × 10 ³ Ω · cm or less, more preferably 1.0 × 10 ² Ω · cm or less.
When the volume resistivity is less than 1.0 × 10 ⁻⁴ Ω · cm, good conductivity can be obtained, but the resin content decreases and the moldability is inferior, exceeding 1.0 × 10 ⁴ Ω · cm. And conductivity is insufficient.
In order to make the volume resistivity of the cured product obtained by curing the composition of the present invention within the above range, the conductive polymer (A) and the protonic acid dopant (B) are appropriately selected, and their content ratios and It can be adjusted by making the dispersibility suitable.

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 the volume resistivity is 1 × 10 ⁰ Ω · cm or less, so that the conductivity is excellent.
More specifically, the volume resistivity is measured by the method described in Examples described later.

[Surface contact angle of cured product]
In the composition of the present invention, the surface contact angle of the cured product after curing is preferably 75 ° or less, more preferably 65 ° or less, and further preferably 63 ° or less. The lower limit of the surface contact angle is not particularly limited, but is usually 15 ° or more.
In the present invention, when the surface contact angle is 75 ° or less, the cured product obtained by curing the composition of the present invention has excellent wettability, and adhesion between various materials using the composition and paints, gel coats, and the like. When it is used outdoors, it has the advantage that the surface-coated product is less peeled off and dropped off, and an improvement in the weather resistance of the cured product can be expected.
In order to set the surface contact angle of the cured product within the above range, a compound having many functional groups such as an epoxy group may be used as the compound (C).
In the present invention, the surface contact angle can be measured using a surface contact angle meter. More specifically, the surface contact angle is measured by the method described in Examples described later.

[Conductive polymer (A)]
In the present invention, polyaniline, polyaniline derivatives, polyphenylene vinylene, 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 a polyaniline derivative.
Polyaniline is an insulator in the emeraldine base (EB) state represented by the following formula (1).

When this polyaniline in the EB state is doped with a proton acid dopant H ⁺ A ⁻ (dissociated state), an salt is formed with an imino group in the polyaniline, which is shown in the following formula (2) which is an electronic state showing conductivity. Changes to the emeraldine salt (ES) state.
In addition, the electronic state of polyaniline can be confirmed from a UV-vis-NIR spectrum.

[Protic acid dopant (B)]
The proton acid dopant (B) is used to make the conductive polymer (A) in the EB state conductive.
In the present invention, as the protonic acid dopant (B), 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. Of these, 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 a large steric hindrance as the protonic acid dopant (B).
Specific examples of the organic acid having a site having a large steric hindrance include benzenesulfonic acid, toluenesulfonic acid, polystyrenesulfonic acid, alkylnaphthalenesulfonic acid, anthraquinonesulfonic acid in addition to dodecylbenzenesulfonic acid represented by the following formula (3). Organic sulfonic acids such as alkyl sulfonic acid, dodecyl sulfonic acid, camphor sulfonic acid, dioctyl sulfosuccinic acid, porphyrin tetrasulfonic acid, polyvinyl sulfonic acid; propyl phosphoric acid, butyl phosphoric acid, hexyl phosphoric acid, polyethylene oxide dodecyl ether phosphoric acid, polyethylene oxide And organic phosphoric acid such as alkyl ether phosphoric acid. Among these, dodecyl sulfonic acid, alkyl sulfonic acid, dodecyl benzene sulfonic acid, butyl phosphoric acid, and hexyl phosphoric acid are more preferable.

Even if a rigid polyaniline main chain is doped with a dopant of an inorganic acid such as hydrochloric acid, the polyaniline is insoluble and infusible and has poor workability. On the other hand, when an organic acid having a site with a large steric hindrance is used as a dopant, the acidic group functions as a dopant, while the steric hindrance part suppresses the interaction between polyaniline main chains and improves mobility. As a result, good dispersibility with organic chemicals and processability are improved. Therefore, it can be said that such a protonic acid dopant is a functional dopant capable of expressing the conductivity of polyaniline and improving the processability.
The protonic acid dopant (B) may be used alone or in combination of two or more. For example, in order to adjust the viscosity, compatible liquid and solid protonic dopants can be used in combination.

[Compound (C)]
In the present invention, a compound (C) having an alicyclic skeleton and an epoxy group is used as a polymerization monomer.
The 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 the molecule (in one molecule). It is a compound that has. Specifically, as the compound (C), (i) a compound having an epoxy group (alicyclic epoxy group) composed of two adjacent carbon atoms and oxygen atoms constituting the alicyclic skeleton, (ii) ) A compound having an epoxy group that is directly single-bonded to a carbon atom constituting the alicyclic skeleton, and (iii) a hydrogenated aromatic glycidyl ether-based epoxy compound. These may be used alone or in combination. May be used in combination.
In the present invention, the proton acid dopant (B) functions as a cationic polymerization initiator and does not use a cationic reactive catalyst. Further, 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 (i) a compound having an epoxy group composed of two adjacent carbon atoms and oxygen atoms constituting the 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 adjacent carbon atoms and oxygen atoms constituting a cyclohexane ring). Specifically, a compound (alicyclic epoxy compound) represented by the following formula (4) is exemplified.

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

Examples of the alicyclic hydrocarbon group include 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 thereof include C4-15 bridged cyclic hydrocarbon groups such as bicycloheptanyl group and bicycloheptenyl group.
As said aromatic hydrocarbon group, C6-14 aryl groups (especially C6-10 aryl group), such as a phenyl group and a naphthyl group, etc. are mentioned, for example.
Examples of the group in which the aliphatic hydrocarbon group and the alicyclic hydrocarbon group are bonded include a cyclohexylmethyl group and a methylcyclohexyl group. Examples of the group in which an aliphatic hydrocarbon group and an aromatic hydrocarbon group are bonded include, for example, 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 a group, and C2-4 alkenyl-substituted aryl groups such as a styryl group.

  The hydrocarbon group may have a substituent. Although carbon number of the substituent in the said hydrocarbon group is not specifically limited, 0-20 are preferable, More preferably, it is 0-10. Examples of the substituent include halogen atoms such as fluorine atom, chlorine atom, bromine atom and iodine atom; hydroxyl group; alkoxy group such as methoxy group, ethoxy group, propoxy group, isopropyloxy group, butoxy group and isobutyloxy group (Especially C1-6 alkoxy group); alkenyloxy group such as allyloxy group (particularly C2-6 alkenyloxy group); C1-4 alkyl group, C2 on aromatic ring such as phenoxy group, tolyloxy group, naphthyloxy group, etc. -4 alkenyl group, halogen atom, aryloxy group which may have 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 groups, benzoyloxy groups and other acyloxy groups (particularly C1-12 acyloxy groups); mercapto groups; methylthio groups, ethylthio groups and other alkylthio groups (particularly C1-6 alkylthio groups); allylthio groups, etc. Alkenylthio group (especially C2-6 alkenylthio group); C1-4 alkyl group, C2-4 alkenyl group, halogen atom, C1-4 alkoxy group and the like on the aromatic ring such as phenylthio group, tolylthio group, naphthylthio group, etc. Arylthio groups (especially C6-14 arylthio groups) which may have a substituent of aralkylthio groups such as benzylthio groups and phenethylthio groups (particularly C7-18 aralkylthio groups); carboxyl groups; methoxycarbonyl groups , Ethoxycarbonyl group, propoxycarbonyl group, butoxycarbo An alkoxycarbonyl group (particularly a C1-6 alkoxy-carbonyl group); an aryloxycarbonyl group such as a phenoxycarbonyl group, a tolyloxycarbonyl group, a naphthyloxycarbonyl group (particularly a 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 (particularly Mono- or di-C1-6 alkylamino group); acylamino groups such as acetylamino group, propionylamino group, benzoylamino group (especially C1-11 acylamino group); epoxy group, glycidyl group, glycidyloxy group, cyclohexene An epoxy group-containing group such as an oxide group; an oxetanyl group-containing group such as an ethyl oxetanyloxy group; an acyl group such as an acetyl group, a propionyl group, or a benzoyl group; an oxo group; And the like are groups bonded through.

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

In the above formula (4-1), 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 a group in which a plurality of these are linked.
Examples of the alicyclic epoxy compound in which Y in formula (4-1) is a single bond include 3,4,3 ′, 4′-diepoxybicyclohexane.

As said bivalent hydrocarbon group, a C1-C18 linear or branched alkylene group, a bivalent alicyclic hydrocarbon group, etc. are mentioned. Examples of the linear or branched alkylene group having 1 to 18 carbon atoms include a methylene group, a methylmethylene group, a dimethylmethylene group, an ethylene group, a propylene group, and a trimethylene group. Examples of the divalent alicyclic hydrocarbon group include 1,2-cyclopentylene group, 1,3-cyclopentylene group, cyclopentylidene group, 1,2-cyclohexylene group, 1,3-cyclohexene group. And divalent cycloalkylene groups (including cycloalkylidene groups) such as a silylene group, 1,4-cyclohexylene group, and cyclohexylidene group.
The linking group Y is particularly preferably a linking group containing an oxygen atom, specifically, for example, —CO—, —O—CO—O—, —COO—, —O—, —CONH—; A group in which a plurality of these groups are linked; a group in which one or more of these groups are linked to one or more of divalent hydrocarbon groups, and the like. 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-epoxycyclohexane-1-yl) ethane, 1,2-epoxy-1,2-bis (3,4-epoxycyclohexane-1-yl) ethane, 2,2-bis (3,4-epoxycyclohexane-1-yl) propane and the like.
In the following formulas (I-5) and (I-7), l and m 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, methylene group, ethylene group, propylene group, isopropylene group, butylene group, isobutylene group, s-butylene group, pentylene group, hexylene. And linear or branched alkylene groups such as a group, a heptylene group, and an octylene group. Among these, C1-C3 linear or branched alkylene groups, such as a methylene group, ethylene group, a propylene group, an isopropylene group, are preferable. 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 commercial names such as trade names “Celoxide 2021P” and “Celoxide 2081” (manufactured by Daicel Corporation). Can also be used.

  Examples of the compound (ii) having an epoxy group that is directly single-bonded to a carbon atom constituting the alicyclic skeleton (hereinafter sometimes referred to as “epoxy compound (ii)”) include, for example, Examples thereof include compounds represented by formula (II).

In the formula (II), R ′ is a group (p-valent organic group) obtained by removing p hydroxy 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 to 6, and n is preferably 1 to 30. When p is 2 or more, n in each () (inside the outer parenthesis) may be the same or different.
Specific examples of the compound represented by the above formula (II) include 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.].

Examples of the (iii) hydrogenated aromatic glycidyl ether type epoxy compound (hereinafter sometimes referred to as “epoxy compound (iii)”) include, for example, 2,2-bis [4- (2,3-epoxypropoxy). ) Bisphenol A type such as cyclohexyl] propane, 2,2-bis [3,5-dimethyl-4- (2,3-epoxypropoxy) cyclohexyl] propane, a compound represented by the following formula (III) Compound obtained by hydrogenating an epoxy compound (nuclear hydrogenated bisphenol A type epoxy compound); 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] Compound obtained by hydrogenating bisphenol F type epoxy compound such as methane (nuclear hydrogenated bisphenol F type epoxy compound); Hydrogenated biphenol type epoxy compound; Hydrogenated phenol novolak type epoxy compound; Hydrogenated cresol novolak Type epoxy compound; hydrogenated epoxy compound of cresol novolac type epoxy compound of bisphenol A; hydrogenated naphthalene type epoxy compound; hydrogenated epoxy compound of epoxy compound obtained from trisphenolmethane, and the like.
As a 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 (for example, an integer of 1 to 5).

  The above 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 to 2,000. Further, from the viewpoint of easy preparation of the composition, the weight average molecular weight of the compound (C) is more preferably 200 to 1000, and still more preferably 200 to 500.

[Content ratio]
In the composition of the present invention, 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. Further, the content of the compound (C) in the composition of the present invention is preferably 50% by mass or less, more preferably 40% by mass or less from the same viewpoint as described above.
In the composition of the present invention, when the conductive polymer (A) is polyaniline, the nitrogen atom of the polyaniline and the proton acid dopant (B) are in a molar ratio [nitrogen atom of polyaniline: protonic acid dopant], preferably 10 : 1-1: 2.
If the amount of the protonic acid dopant (B) is too small, the polymerization / curing reaction does not proceed sufficiently even when heated, and the state of polyaniline changes from the ES state to the EB state, resulting in loss of conductivity. On the other hand, if the protonic acid dopant (B) is present in excess of this range, it becomes difficult to form a conductive path with polyaniline, and a reaction with exotherm starts at room temperature without heating, unless it shows good conductivity. It becomes difficult to control the reaction and hardens quickly.

In the composition of the present invention, the total of the conductive polymer (A) and the protonic acid dopant (B) and the compound (C) are in a mass ratio [the 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.
As the total of the conductive polymer (A) and the proton acid dopant (B) increases, the conductivity of the composition increases. Moreover, if it is in the range of the said mass ratio, the composite of a conductive polymer (A) and a proton acid dopant (B) will be disperse | distributed suitably in a composition, and it will become easy to express the outstanding electroconductivity.

[Other epoxy compounds (D)]
In order to improve the low viscosity and the storage stability, the composition of the present invention may be referred to as other epoxy compound (D) other than the above compound (C) (hereinafter referred to as “other epoxy compound (D)”). ) Can be used in combination.
Examples of the other epoxy compound (D) include aromatic glycidyl ether type epoxy compounds [for example, bisphenol A type epoxy compound, bisphenol F type epoxy compound, biphenol type epoxy compound, phenol novolac type epoxy compound, cresol novolac type epoxy. Compound, cresol novolac type epoxy compound of bisphenol A, naphthalene type epoxy compound, epoxy compound obtained from trisphenol methane], aliphatic glycidyl ether type epoxy compound [eg, aliphatic polyglycidyl ether type], glycidyl ester type epoxy compound Glycidylamine epoxy compounds, isocyanurate compounds having an epoxy group [for example, diallyl monoglycidyl isocyanurate compounds, monoaryls Diglycidyl isocyanurate compound, triglycidyl isocyanurate compounds] are exemplified.
In the composition of this invention, you may use said other epoxy compound (D) individually or in combination of multiple types.
The viscosity of the composition can be adjusted by using another epoxy compound (D).
The content of the other epoxy compound (D) is not particularly limited, but can be added in an appropriate ratio according to the viscosity of the composition.

[Curing agent (E)]
When the composition of the present invention contains the other epoxy compound (D), it can further contain a curing agent (E).
As the curing agent (E), a known or conventional curing agent can be used as a curing agent for epoxy resin, and is not particularly limited. For example, acid anhydrides (acid anhydride curing agents), amines ( Amine curing agents), polyamide resins, imidazoles (imidazole curing agents), polymercaptans (polymercaptan curing agents), phenols (phenolic curing agents), polycarboxylic acids, dicyandiamides, organic acid hydrazides, etc. Can be mentioned. The said hardening | curing agent (E) may be used individually or in combination of multiple types.

[Curing accelerator (F)]
When the composition of the present invention contains the other epoxy compound (D), it can further contain a curing accelerator (F).
A hardening accelerator (F) is a compound which has a function which accelerates | stimulates the reaction rate, when another epoxy compound (D) reacts with a hardening | curing agent (E).
The curing accelerator (F) may be a known or conventional curing accelerator, and is not particularly limited. For example, 1,8-diazabicyclo [5.4.0] undecene-7 (DBU) or a salt thereof (for example, , 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; Acid esters; phosphines such as triphenylphosphine and tris (dimethoxy) phosphine; phosphonium compounds such as tetraphenylphosphonium tetra (p-tolyl) borate; organometallic salts such as zinc octylate, tin octylate and zinc stearate; Examples thereof include metal chelates such as aluminum acetylacetone complex. The said hardening accelerator (F) may be used individually or in combination of multiple types.

  As the curing accelerator (F), trade names “U-CAT SA 506”, “U-CAT SA 102”, “U-CAT5003”, “U-CAT18X”, “U-CAT12XD” (developed product) (above) Trade name “TPP-K”, “TPP-MK” (above, manufactured by Hokuko Chemical Co., Ltd.); trade name “PX-4ET” (manufactured by Nippon Chemical Industry Co., Ltd.), etc. It is also possible to use commercially available products.

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

As the thermoplastic resin, the main chain includes 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. A thermoplastic resin having a bond selected from is preferably used.
Among them, for example, 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.
From the viewpoint of excellent heat resistance, polyimide, polyetherimide, polysulfone, polyethersulfone and the like are particularly preferably used. Among these, polyethersulfone is more preferable because it can increase toughness while maintaining the heat resistance and elastic modulus of the cured product.
Moreover, it is preferable that these thermoplastic resins have a functional group reactive with the thermosetting resin from the viewpoint of improving toughness and maintaining the environmental resistance of the cured resin. Particularly preferred functional groups include a carboxyl group, an amino group, and a hydroxyl group.

<Method for producing thermosetting conductive composition>
In the composition of the present invention, the conductive polymer (A) and the protonic acid dopant (B) are mixed to disperse the conductive polymer (A) in the protonic acid dopant (B). After preparing a complex composed of the protonic acid dopant (B), the complex, the compound (C) and, if necessary, (D) to (F) and other components may be mixed and dispersed. it can.
There are no particular limitations on the apparatus used for the mixing, for example, ball mill, bead mill, planetary ball mill, vibrating ball mill, sand mill, colloid mill, attritor, roll mill, high-speed impeller dispersion, disperser, homogenizer, high-speed impact mill, ultrasonic Examples thereof include a mechanical stirring method using dispersion and stirring blades.

<Method for producing cured product>
In the curing of the composition of the present invention, the polymerization reaction proceeds with the protonic acid dopant (B) as a polymerization initiator as described above. The polymerization reaction may be performed at a higher temperature, and is preferably performed at about 100 to 250 ° C. By setting the curing temperature to 100 ° C. or higher, the curing time is shortened, and by setting it to 250 ° C. or lower, side reactions may occur due to oxygen in the air, or defects in conductivity, moldability and wettability may occur. The fear is suppressed.

  The composition of this invention can obtain the hardened | cured material which is excellent in storage stability and excellent in electroconductivity, a moldability, and wettability. Such characteristics of the composition of the present invention can be maintained even when the viscosity is adjusted. Therefore, the composition of the present invention can be applied to a prepreg by impregnating a fiber reinforcement, and can be used for a wide range of applications requiring conductivity such as resin films, paints, and housings of various electronic devices.

  EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention concretely, this invention is not limited to these.

The compound (C) used in the examples is as follows.
(C): Celoxide 2021P: Trade name “Celoxide 2021P” [3,4-epoxycyclohexylmethyl (3,4-epoxy) cyclohexanecarboxylate], molecular weight 252, manufactured by Daicel Corporation

About the composition and hardened | cured material of an Example and a comparative example, the following hardening reaction start temperature, volume resistivity, surface contact angle, and sclerosis | hardenability were evaluated.
<Evaluation method>
(1) Curing reaction start temperature (storage stability)
6 to 10 mg of the composition obtained in Examples or Comparative Examples is placed in a differential scanning calorimeter as a sample. The sample is then heated at 5 ° C / min to reach a final temperature of 200-230 ° C. The curing reaction initiation temperature was determined from the intersection of the inflection point and base line tangent of the exothermic curve obtained by differential scanning calorimetry.
When the curing reaction start temperature was less than 70 ° C., the storage stability was insufficient, and when it was 70 ° C. or more, the storage stability was evaluated as good.
In this example, the storage stability of the resin composition is preferably higher at the curing reaction start temperature.
(2) Volume resistivity (conductivity)
A sample for measurement (about 100 mm × about 100 mm × about 200 μm) is prepared using the cured product obtained in the example or the comparative example, and a resistivity meter “Loresta GP” (Loresta GPCP-T610 type resistivity meter, JIS The volume resistance value (Ω · cm) was measured using K 7194: 1994 compliant, 4-terminal 4-probe method, constant-current application method, manufactured by Mitsubishi Chemical Analytech Co., Ltd. (4-terminal probe at 0.5 cm intervals).
In this example, the smaller the value, the better the conductivity.
(3) Surface contact angle (wetting)
The cured product obtained in Examples or Comparative Examples was allowed to stand on a horizontal plane, and 8 μL of pure water droplets were dropped from a direction perpendicular to the horizontal plane onto a polymer composite or the like. The surface contact angle was measured in a “droplet method: θ / 2 method” mode using a surface contact angle meter WPI-3000 (manufactured by Kyowa Chemical Industry Co., Ltd.).
It can be said that the smaller the value of the surface contact angle, the higher the hydrophilicity of the surface.
(4) Curability (formability)
The curability of the compositions obtained in Examples or Comparative Examples was evaluated according to the following criteria.
○: The curing reaction proceeds well and the remainder of the reaction does not occur.
(Triangle | delta): Although hardening reaction advances, malfunctions, such as the smell of a residual monomer, arise.
X: The curing reaction does not proceed, or even if it progresses, a problem such as uncured liquid remains and tack occurs.

[Example 1]
(1) Preparation of polyaniline-dodecylbenzenesulfonic acid complex [mixture of conductive polymer (A) and protonic acid dopant (B)]
30 parts of polyaniline (PANI) in a commercially available emeraldine base (EB) state and 70 parts of dodecylbenzenesulfonic acid (DBSA) are blended in a three-roll mill and kneaded so as to be uniformly dispersed to obtain a paste-like mixture. (Polyaniline A-dodecylbenzenesulfonic acid complex) was obtained.
(2) Composition 3 g of alicyclic epoxy compound (compound (C), ceroxide 2021P, equivalent to the above-mentioned epoxy compound (i)) is added to 7 g of the above polyaniline A-dodecylbenzenesulfonic acid complex, and a three roll mill machine. A paste-like composition with good dispersion was obtained. Using the obtained composition, the curing reaction initiation temperature was determined by the method described above.
Moreover, the obtained composition was heated at 150 degreeC for 1.5 hours, and the sheet-like hardened | cured material was obtained. Using the obtained cured product, volume resistivity, surface contact angle, and curability were evaluated by the method described above.
Various evaluation results are shown in Table 1.

[Comparative Example 1]
To 5 g of the polyaniline A-dodecylbenzenesulfonic acid complex obtained in (1) of Example 1, 5 g of divinylbenzene ((C ′)) was added, and the mixture was stirred at room temperature for 20 minutes using a rotating and rotating mixer. A paste-like polyaniline composition in which the polyaniline A-dodecylbenzenesulfonic acid complex was well dispersed was obtained. During the stirring, it was felt that the viscosity of the composition gradually increased.
Using the obtained composition, it heated at 120 degreeC for 1.5 hours, and obtained the sheet-like hardened | cured material. However, the cured product had a residual monomer odor. Various evaluations were performed on the obtained compositions and cured products by the above-described methods, and the results are shown in Table 1.

[Comparative Example 2]
To 4 g of the polyaniline A-dodecylbenzenesulfonic acid complex obtained in (1) of Example 1, 6 g of alicyclic epoxy (compound (C), ceroxide 2021P, equivalent to the above-mentioned epoxy compound (i)) was added, and the rotation The mixture was stirred at room temperature for 20 minutes using a revolutionary mixer to obtain a creamy low viscosity composition.
Although the obtained composition was heated at 150 ° C. for 1.5 hours, the unreacted composition remained and became a sticky product, and no cured product was obtained.
About the obtained composition, hardening reaction start temperature was calculated | required by the above-mentioned method. Moreover, since the hardened | cured material was not obtained, the measurement of a volume resistivity and a surface contact angle could not be implemented, but sclerosis | hardenability was evaluated about the said viscous material.
Various evaluation results are shown in Table 1.

  The composition of the present invention can be applied to a prepreg by impregnating a fiber reinforcement due to its characteristics, and is useful for a wide range of applications requiring conductivity such as resin films, paints, and housings of various electronic devices.

Claims (9)

A thermosetting conductive composition satisfying the following (1) and (2), comprising a conductive polymer (A), a protonic acid dopant (B), and a compound (C) having an alicyclic skeleton and an epoxy group.
(1) The curing reaction start temperature of the thermosetting conductive composition measured with a differential scanning calorimeter is 70 ° C. or higher. (2) The volume resistivity of the cured product after curing is 1.0 × 10 ^{−. 4} Ω · cm or more and 1.0 × 10 ⁴ Ω · cm or less   The thermosetting conductive composition according to claim 1, wherein the compound (C) has a weight average molecular weight of 200 to 2,000.   The thermosetting conductive composition according to claim 1 or 2, wherein the content of the compound (C) is 5% by mass or more and 50% by mass or less.   The thermosetting conductive composition according to any one of claims 1 to 3, wherein the conductive polymer (A) is polyaniline.   The thermosetting conductive composition according to claim 4, wherein a molar ratio of a nitrogen atom of the polyaniline to the protonic acid dopant (B) is 10: 1 to 1: 2.   The mass ratio of the sum total of the said conductive polymer (A) and the said proton acid dopant (B), and the said compound (C) is 1: 1-1: 0.1, Any one of Claims 1-5 The thermosetting conductive composition described in 1.   The compound (C) is (i) a compound having an epoxy group composed of two adjacent carbon atoms and oxygen atoms constituting the alicyclic skeleton, and (ii) constituting an alicyclic skeleton. The heat according to any one of claims 1 to 6, 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-based epoxy compound. A curable conductive composition.   The thermosetting conductive composition according to any one of claims 1 to 7, wherein the protonic acid dopant (B) is an organic sulfonic acid.   The thermosetting conductive composition according to any one of claims 1 to 8, wherein a surface contact angle of the cured product after curing is 75 ° or less.