JP2013117081A - Method for producing sizing agent-applied carbon fiber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a sizing agent-applied carbon fiber that has superior adhesiveness between a carbon fiber and a matrix resin and superior high-order processability, and also does not cause unevenness in an adhesion area.SOLUTION: The method for producing the sizing agent-applied carbon fiber comprises: applying a sizing agent prepared by blending 100 pts.mass of an epoxy compound having two or more epoxy groups or two types or more functional groups, as a component (A) and 0.1-25 pts.mass of one or more compounds selected from the group consisting of a tertiary amine compound, a tertiary amine salt, a quaternary ammonium salt, a quaternary phosphonium salt and a phosphine compound, as a component (B), to a carbon fiber; and heat-treating the carbon fiber by microwave irradiation and/or infrared ray irradiation.

Description

  The present invention relates to a method for producing sizing agent-coated carbon fibers and sizing agent-coated carbon fibers that are suitably used for aircraft members, spacecraft members, automobile members, ship members, and the like. More specifically, the present invention relates to a method for producing a sizing agent-coated carbon fiber that is excellent in adhesiveness with a matrix resin and is excellent in high-order processability.

  Since carbon fiber is lightweight and has excellent strength and elastic modulus, many composite materials combined with various matrix resins are used for aircraft members, spacecraft members, automobile members, ship members, civil engineering and building materials, and sporting goods. Used in the field. In a composite material using carbon fibers, in order to make use of the excellent characteristics of carbon fibers, it is important that the adhesion between the carbon fibers and the matrix resin is excellent.

  In order to improve the adhesion between the carbon fiber and the matrix resin, a method of introducing an oxygen-containing functional group on the surface of the carbon fiber is usually performed by subjecting the carbon fiber to oxidation treatment such as gas phase oxidation or liquid phase oxidation. . For example, a method of improving the interlaminar shear strength, which is an index of adhesiveness, by subjecting carbon fibers to electrolytic treatment has been proposed (see Patent Document 1). However, in recent years, as the level of required properties for composite materials has improved, the adhesion that can be achieved by such oxidation treatment alone is becoming insufficient.

  On the other hand, since carbon fiber is brittle and has poor convergence and friction resistance, fluff and yarn breakage are likely to occur in the high-order processing step. For this reason, the method of apply | coating to carbon fiber is proposed (refer patent document 2 and 3).

  For example, a method of applying diglycidyl ether of bisphenol A as a sizing agent to carbon fibers has been proposed (see Patent Documents 2 and 3). In addition, a method of applying a polyalkylene oxide adduct of bisphenol A as a sizing agent to carbon fibers has been proposed (see Patent Documents 4 and 5). Moreover, the method of apply | coating what added the epoxy group to the polyalkylene oxide addition product of bisphenol A as a sizing agent to carbon fiber is proposed (refer patent documents 6 and 7). Furthermore, a method of applying an epoxy adduct of polyalkylene glycol as a sizing agent to carbon fibers has been proposed (see Patent Documents 8, 9 and 10).

  Separately, a method of applying a urethane compound having an epoxy group and a quaternary ammonium salt as a sizing agent to carbon fibers has been proposed (see Patent Document 11). Even with this proposed method, the convergence and friction resistance are improved, but the adhesion between the carbon fiber and the matrix resin cannot be improved.

  According to these methods, it is known that the converging property and friction resistance of the carbon fiber are improved. However, these conventional proposals do not have a technical idea of positively improving the adhesion between the carbon fiber and the matrix resin by using a sizing agent, and actually greatly improve the adhesion between the carbon fiber and the matrix resin. I couldn't.

  On the other hand, a method of applying a specific sizing agent to carbon fibers has been performed for the purpose of improving the impregnation property of the matrix resin into the carbon fibers.

  For example, a method of applying a cationic surfactant having a surface tension of 40 mN / m or less and a viscosity at 80 ° C. of 200 mPa · s or less as a sizing agent to carbon fibers has been proposed (see Patent Document 12). Further, a method of applying an epoxy resin, a water-soluble polyurethane resin, and a polyether resin as sizing agents to carbon fibers has been proposed (see Patent Document 13). According to these methods, it has been recognized that the carbon fiber is easily bundled and the matrix resin is impregnated into the carbon fiber. However, these conventional proposals do not have a technical idea of positively improving the adhesion between the carbon fiber and the matrix resin by using the sizing agent, and the adhesion between the carbon fiber and the matrix resin is actually greatly improved. I couldn't make it.

  Thus, the sizing agent is conventionally used as a so-called paste agent for the purpose of improving high-order processability and the purpose of improving the impregnation property of the matrix resin into the carbon fiber. There has been almost no investigation to improve the adhesiveness. Moreover, even in the studied examples, the effect of improving the adhesiveness is insufficient, or the effect is limited only in combination with a special carbon fiber.

  For example, a method of applying N, N, N ′, N′-tetraglycidylmetaxylylenediamine as a sizing agent to carbon fibers has been proposed (see Patent Document 14). However, this proposed method shows that the interlaminar shear strength, which is an index of adhesion, is improved as compared with the case where glycidyl ether of bisphenol A is used, but the effect of improving adhesion is still insufficient. Met. In addition, N, N, N ′, N′-tetraglycidylmetaxylylenediamine used in this proposal contains an aliphatic tertiary amine in the skeleton and has nucleophilicity. In particular, there is a problem that the carbon fiber bundle becomes hard and the high-order workability is lowered.

Further, a method has been proposed in which a mixture of a vinyl compound monomer having a glycidyl group and an amine curing agent for epoxy resin is applied to carbon fibers as a sizing agent (see Patent Document 15). However, although this proposed method has been shown to improve the interlaminar shear strength, which is an index of adhesion, compared with the case where no amine curing agent is used, the effect of improving adhesion is still insufficient. It was. In addition, the glycidyl group and amine curing agent react with each other in the drying process of the sizing agent to increase the molecular weight. As a result, the carbon fiber bundle becomes hard and the high-order workability decreases, and the gaps between the carbon fibers become narrower and the resin. There was a problem that the impregnation property of the resin deteriorated.
Another method using a sizing agent in which an epoxy compound and an amine curing agent are used in combination has been proposed (see Patent Document 16). However, according to this proposal, the handling property and impregnation property of the fiber bundle are improved, but the adhesion between the carbon fiber and the epoxy matrix resin is inhibited by the film formation of the high molecular weight sizing agent on the carbon fiber surface. There was a case.
Furthermore, a method of applying an amine compound to carbon fibers has been proposed (see Patent Document 17). However, although the proposed method shows that the interlaminar shear strength, which is an index of adhesion, is improved as compared with the case where nothing is applied, the effect of improving adhesion is still insufficient. In this proposal, there is no detailed description of the adhesion improvement mechanism, but it is presumed that it is roughly the following mechanism. That is, in this proposal, diethylenetriamine containing a primary amino group, xylenediamine, piperidine containing a secondary amino group, and imidazole are used as amine compounds. It is considered that the active hydrogen acts on the epoxy matrix resin and accelerates the curing reaction. For example, the hydroxyl group formed by the reaction of the epoxy matrix and the amine compound, the carboxyl group on the carbon fiber surface, the hydroxyl group, etc. It is thought that the adhesion is improved by forming an action. However, as described above, the result of improvement in adhesion is still insufficient with this proposal, and it cannot be said that the demands for composite materials in recent years are satisfied.

  Furthermore, as another example using an amine compound as a sizing agent, a method using a thermosetting resin and a cured product of an amine compound has been proposed (see Patent Document 18). In this proposal, m-xylenediamine containing a primary amino group and piperazine containing a secondary amino group are used as an amine compound. The purpose of this proposal is to improve the convergence and handling of the carbon fiber bundle by actively reacting the active hydrogen contained in the amine compound with a thermosetting resin represented by an epoxy resin to produce a cured product. Met. This carbon fiber bundle was limited to chopped applications, and the mechanical properties related to the adhesiveness of the molded product after melt-kneading with a thermoplastic resin were still insufficient.

  Further, carbon fibers having surface oxygen concentration O / C, surface hydroxyl group concentration and carboxyl group concentration within specific ranges are used, and an aliphatic compound having a plurality of epoxy groups is applied to the carbon fiber as a sizing agent. A method has been proposed (see Patent Document 19). However, this proposed method has been shown to improve EDS, which is an index of adhesion, but the effect of improving the adhesion between the carbon fiber and the matrix resin is still insufficient, and adhesion The improvement effect was limited to be manifested only when combined with special carbon fibers.

Japanese Patent Laid-Open No. 04-361619 US Pat. No. 3,957,716 JP-A-57-171767 JP 07-009444 A JP 2000-336577 A JP 61-028074 A Japanese Patent Laid-Open No. 01-272867 JP-A-57-128266 U.S. Pat. No. 4,555,446 JP 62-033872 A U.S. Pat. No. 4,496,671 JP 2010-31424 A JP-A-2005-320641 JP 52-059794 A JP-A-52-045673 JP 2005-146429 A JP-A-52-045672 JP 09-217281 A US Pat. No. 5,691,055

  Accordingly, in view of the above-mentioned problems in the prior art, an object of the present invention is to provide a method for producing a sizing agent-coated carbon fiber that is excellent in adhesion between carbon fiber and matrix resin and high-order processability and that has no adhesion unevenness. There is.

  The sizing agent includes (A) a specific epoxy compound and (B) a specific tertiary amine compound and / or tertiary amine salt, quaternary ammonium salt, quaternary phosphonisum salt and / or phosphine compound, When a carbon fiber is coated with a sizing agent containing a specific ratio and heated by microwave irradiation and / or infrared irradiation, it is found that adhesion between the carbon fiber and the matrix resin can be improved, and adhesion unevenness can be reduced. The present invention has been conceived.

  That is, in the present invention, as the component (A), the epoxy compound (A1) having two or more epoxy groups and / or one or more epoxy groups, a hydroxyl group, an amide group, an imide group, a urethane group, a urea group An epoxy compound (A2) having at least one functional group selected from sulfonyl group and sulfo group is used, and at least one selected from the group consisting of the following [a], [b] and [c] A method for producing sizing agent-coated carbon fibers coated with various sizing agents, wherein the sizing agent is applied to carbon fibers, and heat treatment is performed by microwave irradiation and / or infrared irradiation. It is a manufacturing method of carbon fiber.

[A] A tertiary amine compound and / or a tertiary amine salt (B1) 0.1 to 25 parts by mass with a molecular weight of 100 g / mol or more used as at least the component (B) with respect to 100 parts by mass of the component (A) A sizing agent formulated with
[B] The following general formula (I) used as at least the component (B) with respect to 100 parts by mass of the component (A)

（式中、Ｒ_１〜Ｒ_４は、それぞれ炭素数１〜２２の炭化水素基を表し、該炭化水素基は水酸基を有していてもよく、該炭化水素基中のＣＨ_２基は、−Ｏ−、−Ｏ−ＣＯ−または−ＣＯ−Ｏ−により置換されていてもよい）、または一般式（ＩＩ）

(Wherein R _{1 to} R ₄ each represent a hydrocarbon group having 1 to 22 carbon atoms, and the hydrocarbon group may have a hydroxyl group, and the CH ₂ group in the hydrocarbon group is- Optionally substituted by O-, -O-CO- or -CO-O-), or general formula (II)

(In the formula, R ₅ represents a hydrocarbon group having 1 to 22 carbon atoms, and the hydrocarbon group may have a hydroxyl group, and the CH ₂ group in the hydrocarbon group represents —O—, — R ₆ and R ₇ each independently represent hydrogen or a hydrocarbon group having 1 to 8 carbon atoms, and CH ₂ group in the hydrocarbon group may be substituted by O—CO— or —CO—O—. Is optionally substituted by —O—, —O—CO— or —CO—O—.) 0.1-25 parts by mass of a quaternary ammonium salt (B2) having a cation moiety A sizing agent formulated with

  [C] A sizing agent obtained by blending 0.1 to 25 parts by mass of the quaternary phosphonium salt and / or the phosphine compound (B3) used as the component (B) with respect to 100 parts by mass of the component (A).

  According to a preferred embodiment of the method for producing a sizing agent-coated carbon fiber of the present invention, in the above invention, the microwave irradiation and / or infrared irradiation is performed by heat treatment at a temperature range of 160 ° C. to 260 ° C. for 30 seconds to 600 seconds. Features.

  Moreover, according to the preferable aspect of the manufacturing method of the sizing agent application | coating carbon fiber of this invention, in the said invention, the (B1) tertiary amine compound and / or tertiary amine salt whose said (a) molecular weight is 100 g / mol or more. Is represented by the following general formula (III)

(In the formula, R ₈ represents a hydrocarbon group having 1 to 22 carbon atoms, and the hydrocarbon group may have a hydroxyl group, and the CH ₂ group in the hydrocarbon group represents —O—, —O, R ₉ may be any one of an alkylene group having 2 to 22 carbon atoms, an alkenylene group having 2 to 22 carbon atoms, or an alkynylene group having 2 to 22 carbon atoms, which may be substituted with —CO— or —CO—O—. R ₁₀ represents hydrogen or a hydrocarbon group having 1 to 22 carbon atoms, and the hydrocarbon group may have a hydroxyl group, and the CH ₂ group in the hydrocarbon group is —O— , -O-CO- or -CO-O-, or R ₈ and R ₁₀ may combine to form an alkylene group having 2 to 11 carbon atoms), Formula (IV)

(In the formula, R _{11 to} R ₁₃ each represent a hydrocarbon group having 1 to 22 carbon atoms, and the hydrocarbon group may have a hydroxyl group, and the CH ₂ group in the hydrocarbon group is- Optionally substituted by O-, -O-CO- or -CO-O-), the following general formula (V)

(In the formula, each of R _{14 to} R ₁₇ represents a hydrocarbon group having 1 to 22 carbon atoms, and the hydrocarbon group may have a hydroxyl group, and the CH ₂ group in the hydrocarbon group is- Optionally substituted by O-, -O-CO- or -CO-O-), the following general formula (VI)

(In the formula, R _{18 to} R ₂₃ each represent a hydrocarbon group having 1 to 22 carbon atoms, and the hydrocarbon group may have a hydroxyl group, and the CH ₂ group in the hydrocarbon group is- It may be substituted with O-, -O-CO- or -CO-O-, R ₂₄ represents a hydroxyl group or a hydrocarbon group having 1 to 22 carbon atoms, and the hydrocarbon group has a hydroxyl group. And the CH ₂ group in the hydrocarbon group may be substituted by —O—, —O—CO— or —CO—O—), the general formula (VII)

（式中、Ｒ_２５〜Ｒ_２７は、それぞれ炭素数１〜８の炭化水素基を表し、該炭化水素基は水酸基を有していてもよい）、および一般式（ＶＩＩＩ）

（式中、Ｒ_２８は、炭素数１〜８の炭化水素基を表し、該炭化水素基は水酸基を有していてもよい）からなる群から選択されるいずれか１つの３級アミン化合物および／または前記３級アミンの塩であることを特徴とする。

(Wherein R _{25 to} R ₂₇ each represent a hydrocarbon group having 1 to 8 carbon atoms, and the hydrocarbon group may have a hydroxyl group), and general formula (VIII)

(Wherein R ₂₈ represents a hydrocarbon group having 1 to 8 carbon atoms, and the hydrocarbon group may have a hydroxyl group), and any one tertiary amine compound selected from the group consisting of / Or a salt of the tertiary amine.

  Moreover, according to the preferable aspect of the manufacturing method of the sizing agent application | coating carbon fiber of this invention, in the said invention, the compound shown by the said general formula (III) is 1, 5- diazabicyclo [4, 3, 0] -5. -Nonene or a salt thereof, or 1,8-diazabicyclo [5,4,0] -7-undecene or a salt thereof.

According to a preferred embodiment of the production method of sizing agent coated carbon fiber of the present invention, in the above invention, the [b] in the general formula (I), R ₃ and R ₄ having 2 to 22 carbon atoms, respectively Represents a hydrocarbon group, and the hydrocarbon group may have a hydroxyl group, and the CH ₂ group in the hydrocarbon group is substituted by —O—, —O—CO— or —CO—O—. It may be possible.

  Moreover, according to the preferable aspect of the manufacturing method of the sizing agent application | coating carbon fiber of this invention, in the said invention, the anion site | part of the quaternary ammonium salt which has the (B2) cation site | part of said [b] is a halogen ion. Features.

  Moreover, according to the preferable aspect of the manufacturing method of the sizing agent application | coating carbon fiber of this invention, in the said invention, (B3) quaternary phosphonium salt and / or phosphine compound of said [c] are the following general formula (IX).

（式中、Ｒ_２９〜Ｒ_３２は、それぞれ炭素数１〜２２の炭化水素基を表し、該炭化水素基は水酸基を有していてもよく、該炭化水素基中のＣＨ_２基は、−Ｏ−、−Ｏ−ＣＯ−または−ＣＯ−Ｏ−により置換されていてもよい）、または一般式（Ｘ）

(In the formula, each of R _{29 to} R ₃₂ represents a hydrocarbon group having 1 to 22 carbon atoms, and the hydrocarbon group may have a hydroxyl group, and the CH ₂ group in the hydrocarbon group is- Optionally substituted by O-, -O-CO- or -CO-O-), or general formula (X)

(Wherein R _{33 to} R ₃₅ each represent a hydrocarbon group having 1 to 22 carbon atoms, and the hydrocarbon group may have a hydroxyl group, and the CH ₂ group in the hydrocarbon group is — The quaternary phosphonium salt or the phosphine compound represented by any one of the following (optionally substituted by O-, -O-CO- or -CO-O-).

  Moreover, according to the preferable aspect of the manufacturing method of the sizing agent application | coating carbon fiber of this invention, in the said invention, (B3) quaternary phosphonium salt and / or phosphine compound 0.1 to 100 mass parts of (A) component. 10 mass parts is mix | blended, It is characterized by the above-mentioned.

  Further, according to a preferred embodiment of the method for producing a sizing agent-coated carbon fiber of the present invention, in the above invention, the carbon fiber is subjected to liquid phase electrolytic oxidation in an alkaline electrolytic solution or liquid phase electrolytic oxidation in an acidic electrolytic solution. Subsequently, after washing with an alkaline aqueous solution, a sizing agent is applied.

  Moreover, according to the preferable aspect of the manufacturing method of the sizing agent application | coating carbon fiber of this invention, the epoxy equivalent of (A) component is less than 360 g / mol in the said invention.

  Moreover, according to the preferable aspect of the manufacturing method of the sizing agent application | coating carbon fiber of this invention, in the said invention, (A) component is an epoxy compound which has a 3 or more epoxy group, It is characterized by the above-mentioned.

  Moreover, according to the preferable aspect of the manufacturing method of the sizing agent application | coating carbon fiber of this invention, in the said invention, (A) component contains an aromatic ring in a molecule | numerator, It is characterized by the above-mentioned.

  Moreover, according to the preferable aspect of the manufacturing method of the sizing agent application | coating carbon fiber of this invention, in the said invention, (A1) component is either a phenol novolak-type epoxy resin, a cresol novolak-type epoxy resin, or tetraglycidyl diamino diphenylmethane. It is characterized by being.

  Moreover, according to the preferable aspect of the manufacturing method of the sizing agent application | coating carbon fiber of this invention, in the said invention, the surface oxygen concentration O / C measured by the X ray photoelectron spectroscopy of carbon fiber is 0.05-0. It is 5, It is characterized by the above-mentioned.

  According to the present invention, in (A) a sizing agent containing a specific epoxy compound as a main component, (B) a specific tertiary amine compound and / or a tertiary amine salt, a quaternary ammonium salt, a quaternary phosphonisum salt, and / or Alternatively, when a specific amount of a phosphine compound is blended and heat treatment is performed by microwave irradiation and / or infrared irradiation, the epoxy compound and the oxygen-containing functional group originally contained on the carbon fiber surface or introduced by oxidation treatment are introduced. Formation of a covalent bond is promoted between the carboxyl group and the oxygen-containing functional group such as a hydroxyl group, and a carbon fiber having excellent adhesion to the matrix resin and having no adhesion unevenness can be obtained.

  Hereinafter, the form for enforcing the manufacturing method of the sizing agent application | coating carbon fiber of this invention in more detail is demonstrated. In the present invention, as the component (A), an epoxy compound (A1) having two or more epoxy groups and / or one or more epoxy groups, a hydroxyl group, an amide group, an imide group, a urethane group, a urea group, a sulfonyl group And an epoxy compound (A2) having at least one functional group selected from a sulfo group and at least one selected from the group consisting of the following [a], [b] and [c] A method for producing a sizing agent-coated carbon fiber coated with a sizing agent, wherein the sizing agent is applied to the carbon fiber, and heat treatment is performed by microwave irradiation and / or infrared irradiation. It is a manufacturing method.

  [A] A tertiary amine compound and / or a tertiary amine salt (B1) 0.1 to 25 parts by mass with a molecular weight of 100 g / mol or more used as at least the component (B) with respect to 100 parts by mass of the component (A) A sizing agent formulated with

[B] The following general formula (I) or general formula (II) used as at least the component (B) with respect to 100 parts by mass of the component (A)

(In the above general formula (I) and general formula (II), R _{1 to} R ₅ each represent a hydrocarbon group having 1 to 22 carbon atoms, and the hydrocarbon group may have a hydroxyl group, The CH ₂ group in the hydrocarbon group may be substituted by —O—, —O—CO— or —CO—O—, wherein R ₆ and R ₇ are each hydrogen or C 1-8. Represents a hydrocarbon group, and the CH ₂ group in the hydrocarbon group may be substituted by —O—, —O—CO— or —CO—O—). A sizing agent comprising 0.1 to 25 parts by mass of a quaternary ammonium salt (B2).

  [C] A sizing agent obtained by blending 0.1 to 25 parts by mass of the quaternary phosphonium salt and / or the phosphine compound (B3) used as the component (B) with respect to 100 parts by mass of the component (A).

  The component (A) used in the present invention is (A1) a compound having two or more epoxy groups in the molecule, and / or (A2) one or more epoxy groups, hydroxyl group, amide group in the molecule. An epoxy compound having at least one functional group selected from imide group, urethane group, urea group, sulfonyl group, and sulfo group.

  The component (B) used in the present invention is any one of (B1) a tertiary amine compound and / or a tertiary amine salt having a molecular weight of 100 g / mol or more, and (B2) any one of the general formula (I) or (II) And (B3) at least one compound selected from quaternary phosphonium salts and / or phosphine compounds.

  The mechanism by which the adhesion is improved by applying a sizing agent containing a specific amount of the component (A) and the component (B) to the carbon fiber and heat-treating with microwave irradiation and / or infrared irradiation is not certain. The component (B) acts on an oxygen-containing functional group such as a carboxyl group and a hydroxyl group of the carbon fiber used in the present invention, and anionizes the hydrogen ion contained in these functional groups, and then anionizes the functional group. And the epoxy group contained in the component (A) is considered to undergo a nucleophilic reaction. This forms a strong bond between the carbon fiber used in the present invention and the epoxy group in the sizing agent. On the other hand, in relation to the matrix resin, each of (A1) and (A2) will be described as follows.

  In the case of (A1), it is considered that the remaining epoxy groups not participating in the covalent bond with the carbon fiber used in the present invention react with the matrix resin-containing functional group to form a covalent bond, or form a hydrogen bond. It is done. In particular, when the matrix resin is an epoxy resin, it is considered that a strong interface can be formed by the reaction between the epoxy group of (A1) and the epoxy group of the matrix resin, or the reaction via the amine curing agent contained in the epoxy resin. . The structure (A1) preferably contains one or more unsaturated groups. When the matrix resin is a radical polymerization resin such as an unsaturated polyester resin or vinyl ester resin, the unsaturated (A1) It is possible for the unsaturated group of the group and the matrix resin to undergo a radical reaction to form a strong interface.

  In the case of (A2), the epoxy group of (A2) forms a covalent bond with an oxygen-containing functional group such as a carboxyl group and a hydroxyl group of the carbon fiber used in the present invention, but the remaining functional groups are a hydroxyl group and an amide group. , An imide group, a urethane group, a urea group, a sulfonyl group, or a sulfo group is considered to form an interaction such as a covalent bond or a hydrogen bond depending on the matrix resin. If the matrix resin is an epoxy resin, the hydroxyl group, amide group, imide group, urethane group, urea group, sulfonyl group, or sulfo group of (A2) reacts with the epoxy group of the matrix resin or the amine curing agent and the epoxy group. It is considered that a strong interface can be formed by the interaction with the hydroxyl group thus formed. Further, if the matrix resin is a thermoplastic resin typified by polyamide, polyester and acid-modified polyolefin, (A2) hydroxyl group, amide group, imide group, urethane group, urea group, sulfonyl group, or sulfo group It is considered that a strong interface can be formed by the interaction with amide groups, ester groups, acid anhydride groups, carboxyl groups such as terminals, hydroxyl groups, and amino groups contained in these matrix resins.

  That is, in the case of (A1), the remaining epoxy group not involved in the covalent bond with the carbon fiber is the hydroxyl group, amide group, imide group, urethane group, urea group, sulfonyl group, or sulfo group in the case of (A2). It is considered to have a function corresponding to the group.

  In the present invention, the epoxy equivalent of the (A) epoxy compound is preferably less than 360 g / mol, more preferably less than 270 g / mol, and even more preferably less than 180 g / mol. When the epoxy equivalent is less than 360 g / mol, covalent bonds are formed at a high density, and the adhesion between the carbon fiber and the matrix resin is further improved. There is no particular lower limit of the epoxy equivalent, but the adhesiveness may be saturated at less than 90 g / mol.

  In the present invention, the (A) epoxy compound is preferably an epoxy resin having 3 or more epoxy groups, and more preferably an epoxy resin having 4 or more epoxy groups. (A) When the epoxy compound is an epoxy resin having three or more epoxy groups in the molecule, even when one epoxy group forms a covalent bond with an oxygen-containing functional group on the surface of the carbon fiber, the remaining two One or more epoxy groups can form a covalent bond or a hydrogen bond with the matrix resin, and the adhesion is further improved. There is no particular upper limit on the number of epoxy groups, but if it is 10 or more, the adhesiveness may be saturated.

  In the present invention, the (A) epoxy compound is preferably an epoxy resin having 3 or more types of two or more functional groups, and more preferably an epoxy resin having 4 or more types of 2 or more functional groups. The functional group possessed by the epoxy compound is preferably selected from a hydroxyl group, an amide group, an imide group, a urethane group, a urea group, a sulfonyl group, or a sulfo group in addition to the epoxy group. (A) When the epoxy compound is an epoxy resin having three or more epoxy groups or other functional groups in the molecule, one epoxy group forms a covalent bond with an oxygen-containing functional group on the carbon fiber surface However, the remaining two or more epoxy groups or other functional groups can form a covalent bond or a hydrogen bond with the matrix resin, and the adhesion is further improved. There is no particular upper limit on the number of epoxy groups, but if it is 10 or more, the adhesiveness may be saturated.

  In the present invention, the (A) epoxy compound preferably has one or more aromatic rings in the molecule, and more preferably has two or more aromatic rings. In a fiber-reinforced composite material composed of carbon fibers and a matrix resin, a so-called interface layer in the vicinity of the carbon fibers may be affected by the carbon fibers or the sizing agent and have different characteristics from the matrix resin. (A) When the epoxy compound has one or more aromatic rings, a rigid interface layer is formed, the stress transmission ability between the carbon fiber and the matrix resin is improved, and the fiber reinforced composite material has a 0 ° tensile strength, etc. Mechanical properties are improved. There is no particular upper limit on the number of aromatic rings, but if it is 10 or more, the mechanical properties may be saturated.

  In the present invention, the (A1) epoxy compound is preferably a phenol novolac epoxy resin, a cresol novolac epoxy resin, or tetraglycidyldiaminodiphenylmethane. These epoxy resins have a large number of epoxy groups, a small epoxy equivalent, and have two or more aromatic rings. In addition to improving the adhesion between carbon fiber and matrix resin, fiber reinforced composite materials Improve mechanical properties such as 0 ° tensile strength. The bifunctional or higher functional epoxy resin is more preferably a phenol novolac type epoxy resin and a cresol novolac type epoxy resin.

  In the present invention, (A1) specific examples of the epoxy compound having two or more epoxy groups include, for example, a glycidyl ether type epoxy resin derived from a polyol, and a glycidyl amine type epoxy derived from an amine having a plurality of active hydrogens. Examples thereof include a resin, a glycidyl ester type epoxy resin derived from polycarboxylic acid, and an epoxy resin obtained by oxidizing a compound having a plurality of double bonds in the molecule.

  Examples of the glycidyl ether type epoxy resin include bisphenol A, bisphenol F, bisphenol AD, bisphenol S, tetrabromobisphenol A, phenol novolac, cresol novolac, hydroquinone, resorcinol, 4,4′-dihydroxy-3,3 ′, 5. , 5'-tetramethylbiphenyl, 1,6-dihydroxynaphthalene, 9,9-bis (4-hydroxyphenyl) fluorene, tris (p-hydroxyphenyl) methane, and tetrakis (p-hydroxyphenyl) ethane and epichlorohydride The glycidyl ether type epoxy resin obtained by reaction with phosphorus is mentioned. Further, as glycidyl ether type epoxy resins, ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, tetrapropylene glycol, polypropylene glycol, trimethylene glycol, 1, 2 -Butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, polybutylene glycol, 1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, 1,4 -Cyclohexanedimethanol, hydrogenated bisphenol A, hydrogenated bisphenol F, glycerol, diglycerol, polyglycerol, trimethylolpropane, penta Risuritoru, sorbitol, and arabitol and a glycidyl ether type epoxy resin obtained by reaction of epichlorohydrin are also exemplified. Examples of the glycidyl ether type epoxy resin include a glycidyl ether type epoxy resin having a dicyclopentadiene skeleton and a glycidyl ether type epoxy resin having a biphenyl aralkyl skeleton.

  Examples of the glycidylamine type epoxy resin include N, N-diglycidylaniline, N, N-diglycidyl-o-toluidine, 1,3-bis (aminomethyl) cyclohexane, m-xylylenediamine, m-phenylenediamine, Examples include 4,4′-diaminodiphenylmethane and 9,9-bis (4-aminophenyl) fluorene.

  Furthermore, for example, as a glycidylamine type epoxy resin, both the hydroxyl group and amino group of aminophenols of m-aminophenol, p-aminophenol, and 4-amino-3-methylphenol are reacted with epichlorohydrin. And epoxy resin obtained.

  Examples of the glycidyl ester type epoxy resin include glycidyl ester type epoxy resins obtained by reacting phthalic acid, terephthalic acid, hexahydrophthalic acid, and dimer acid with epichlorohydrin.

  Examples of the epoxy resin obtained by oxidizing a compound having a plurality of double bonds in the molecule include an epoxy resin having an epoxycyclohexane ring in the molecule. Furthermore, the epoxy resin includes epoxidized soybean oil.

  In addition to these epoxy resins, (A1) epoxy compounds used in the present invention include epoxy resins such as triglycidyl isocyanurate. Furthermore, the epoxy resin synthesize | combined from the epoxy resin mentioned above as a raw material, for example, the epoxy resin synthesize | combined by the oxazolidone ring formation reaction from bisphenol A diglycidyl ether and tolylene diisocyanate is mentioned.

  In the present invention, (A2) an epoxy compound having one or more epoxy groups and at least one functional group selected from a hydroxyl group, an amide group, an imide group, a urethane group, a urea group, a sulfonyl group, and a sulfo group Specific examples of the compound include, for example, a compound having an epoxy group and a hydroxyl group, a compound having an epoxy group and an amide group, a compound having an epoxy group and an imide group, a compound having an epoxy group and a urethane group, and a compound having an epoxy group and a urea group , A compound having an epoxy group and a sulfonyl group, and a compound having an epoxy group and a sulfo group.

  Examples of the compound having an epoxy group and a hydroxyl group include sorbitol-type polyglycidyl ether and glycerol-type polyglycidyl ether. Specifically, Denacol (registered trademark) EX-611, EX-612, EX-614, EX -614B, EX-622, EX-512, EX-521, EX-421, EX-313, EX-314 and EX-321 (manufactured by Nagase ChemteX Corporation).

  Examples of the compound having an epoxy group and an amide group include glycidyl benzamide and amide-modified epoxy resin. The amide-modified epoxy can be obtained by reacting an epoxy group of an epoxy resin having two or more epoxy groups with a carboxyl group of a dicarboxylic acid amide.

  Examples of the compound having an epoxy group and an imide group include glycidyl phthalimide. Specifically, Denacol (trademark registration) EX-731 (made by Nagase ChemteX Corporation) etc. are mentioned.

  Examples of the compound having an epoxy group and a urethane group include a urethane-modified epoxy resin. Specifically, Adeka Resin (registered trademark) EPU-78-13S, EPU-6, EPU-11, EPU-15, EPU- 16A, EPU-16N, EPU-17T-6, EPU-1348, EPU-1395 (manufactured by ADEKA Corporation) and the like. Alternatively, by reacting the terminal hydroxyl group of the polyethylene oxide monoalkyl ether with a polyvalent isocyanate equivalent to the amount of the hydroxyl group, and then reacting the isocyanate residue of the obtained reaction product with the hydroxyl group in the polyvalent epoxy resin. Can be obtained. Here, as the polyvalent isocyanate used, 2,4-tolylene diisocyanate, metaphenylene diisocyanate, paraphenylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, norbornane diisocyanate, triphenylmethane triisocyanate and biphenyl-2, Examples include 4,4′-triisocyanate.

  Examples of the compound having an epoxy group and a urea group include a urea-modified epoxy resin. The urea-modified epoxy can be obtained by reacting the epoxy group of an epoxy resin having two or more epoxy groups with the carboxyl group of the dicarboxylic acid urea.

  Examples of the compound having an epoxy group and a sulfonyl group include bisphenol S-type epoxy.

  Examples of the compound having an epoxy group and a sulfo group include glycidyl p-toluenesulfonate and glycidyl 3-nitrobenzenesulfonate.

  Hereinafter, (B1) to (B3) of the component (B) will be described in order.

  The (B1) tertiary amine compound and / or tertiary amine salt having a molecular weight of 100 g / mol or more used in the present invention is blended in an amount of 0.1 to 25 parts by mass with respect to 100 parts by mass of the (A) epoxy compound. Is required, preferably 0.5 to 20 parts by mass, more preferably 2 to 15 parts by mass, and even more preferably 2 to 8 parts by mass. When the blending amount is less than 0.1 part by mass, the formation of a covalent bond between (A) the epoxy compound and the oxygen-containing functional group on the surface of the carbon fiber is not promoted, and the adhesion between the carbon fiber and the matrix resin is poor. It will be enough. On the other hand, when the blending amount exceeds 25 parts by mass, (B1) covers the carbon fiber surface, the covalent bond formation is inhibited, and the adhesion between the carbon fiber and the matrix resin becomes insufficient.

  The tertiary amine compound and / or tertiary amine salt (B1) having a molecular weight of 100 g / mol or more used in the present invention needs to have a molecular weight of 100 g / mol or more, and the molecular weight is 100 to 400 g. It is preferably within the range of / mol, more preferably within the range of 100 to 300 g / mol, and even more preferably within the range of 100 to 200 g / mol. When the molecular weight is 100 g / mol or more, volatilization is suppressed even during the heat treatment, and a large effect of improving adhesiveness can be obtained even with a small amount. On the other hand, when the molecular weight is 400 g / mol or less, the ratio of active sites in the molecule is high, and a large adhesion improvement effect can be obtained even with a small amount.

  The tertiary amine compound used in the present invention refers to a compound having a tertiary amino group in the molecule. The tertiary amine salt used in the present invention refers to a salt obtained by neutralizing a compound having a tertiary amino group with a proton donor. Here, the proton donor means a compound having active hydrogen that can be donated as a proton to a compound having a tertiary amino group. The active hydrogen refers to a hydrogen atom that is donated as a proton to a basic compound.

  Examples of proton donors include inorganic acids, carboxylic acids, organic acids such as sulfonic acids and phenols, alcohols, mercaptans, and 1,3-dicarbonyl compounds.

  Specific examples of inorganic acids include sulfuric acid, sulfurous acid, persulfuric acid, hydrochloric acid, perchloric acid, nitric acid, phosphoric acid, phosphorous acid, hypophosphorous acid, phosphonic acid, phosphinic acid, pyrophosphoric acid, tripolyphosphoric acid, and amidosulfuric acid. Is mentioned. Of these, sulfuric acid, hydrochloric acid, nitric acid and phosphoric acid are preferably used.

  The carboxylic acids are classified into aliphatic polycarboxylic acids, aromatic polycarboxylic acids, S-containing polycarboxylic acids, aliphatic hydroxycarboxylic acids, aromatic hydroxycarboxylic acids, aliphatic monocarboxylic acids, and aromatic monocarboxylic acids, The following compounds are mentioned.

  Specific examples of the aliphatic polycarboxylic acid include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, peric acid, azelaic acid, sebacic acid, undencanic acid, dodecanedioic acid, tridecanedioic acid, Tetradecanedioic acid, pentadecanedioic acid, methylmalonic acid, ethylmalonic acid, propylmalonic acid, butylmalonic acid, pentylmalonic acid, hexylmalonic acid, dimethylmalonic acid, diethylmalonic acid, methylpropylmalonic acid, methylbutylmalonic acid, Ethylpropylmalonic acid, dipropylmalonic acid, methylsuccinic acid, ethylsuccinic acid, 2,2-dimethylsuccinic acid, 2,3-dimethylsuccinic acid, 2-methylglutaric acid, 3-methylglutaric acid, 3-methyl-3- Ethyl glutaric acid, 3,3-diethyl glutaric acid, 3,3-dimethyl glutar Examples include acid, 3-methyladipic acid, maleic acid, fumaric acid, itaconic acid and citraconic acid.

  Specific examples of the aromatic polycarboxylic acid include phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, and pyromellitic acid.

  Specific examples of the S-containing polycarboxylic acid include thiodipropionic acid.

  Specific examples of the aliphatic hydroxycarboxylic acid include glycolic acid, lactic acid, tartaric acid and castor oil fatty acid.

  Specific examples of the aromatic hydroxycarboxylic acid include salicylic acid, mandelic acid, 4-hydroxybenzoic acid, 1-hydroxy-2-naphthoic acid, 3-hydroxy-2-naphthoic acid and 6-hydroxy-2-naphthoic acid. Can be mentioned.

  Specific examples of the aliphatic monocarboxylic acid include formic acid, acetic acid, propionic acid, butyric acid, isobutyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, octylic acid, pelargonic acid, lauric acid, myristic acid, stearic acid, Examples include behenic acid, undecanoic acid, acrylic acid, methacrylic acid, crotonic acid, and oleic acid.

  Specific examples of the aromatic monocarboxylic acid include benzoic acid, cinnamic acid, naphthoic acid, toluic acid, ethyl benzoic acid, propyl benzoic acid, isopropyl benzoic acid, butyl benzoic acid, isobutyl benzoic acid, sec-butyl benzoic acid, Tertiary butyl benzoic acid, methoxy benzoic acid, ethoxy benzoic acid, propoxy benzoic acid, isopropoxy benzoic acid, butoxy benzoic acid, isobutoxy benzoic acid, second butoxy benzoic acid, tertiary butoxy benzoic acid, amino benzoic acid, N-methyl Aminobenzoic acid, N-ethylaminobenzoic acid, N-propylaminobenzoic acid, N-isopropylaminobenzoic acid, N-butylaminobenzoic acid, N-isobutylaminobenzoic acid, N-secondary butylaminobenzoic acid, N- Tertiary butylaminobenzoic acid, N, N-dimethylaminobenzoic acid, N, N-die Arylamino benzoic acid, and nitrobenzoic acid and fluorosilicone benzoate.

  Of the above carboxylic acids, aromatic polycarboxylic acids, aliphatic monocarboxylic acids, and aromatic carboxylic acids are preferably used. Specifically, phthalic acid, formic acid, and octylic acid are preferably used.

  The sulfonic acid can be classified into aliphatic sulfonic acid and aromatic sulfonic acid, and examples thereof include the following compounds.

  Among the aliphatic sulfonic acids, specific examples of monovalent saturated aliphatic sulfonic acids include methanesulfonic acid, ethanesulfonic acid, propanesulfonic acid, isopropylsulfonic acid, butanesulfonic acid, isobutylsulfonic acid, tert-butylsulfonic acid. , Pentanesulfonic acid, isopentylsulfonic acid, hexanesulfonic acid, nonanesulfonic acid, decanesulfonic acid, undecanesulfonic acid, dodecanesulfonic acid, tridecanesulfonic acid, tetradecanesulfonic acid, n-octylsulfonic acid, dodecylsulfonic acid and cetyl A sulfonic acid etc. are mentioned.

  The aliphatic sulfonic acid may be an unsaturated aliphatic sulfonic acid, and specific examples of the unsaturated aliphatic sulfonic acid include ethylene sulfonic acid and 1-propene-1-sulfonic acid.

  Among aliphatic sulfonic acids, specific examples of divalent or higher aliphatic sulfonic acids include methionic acid, 1,1-ethanedisulfonic acid, 1,2-ethanedisulfonic acid, 1,1-propanedisulfonic acid, 1, Examples thereof include 3-propanedisulfonic acid and polyvinyl sulfonic acid.

  The aliphatic sulfonic acid may be an oxyaliphatic sulfonic acid having a hydroxyl group, and specific examples of the oxyaliphatic sulfonic acid include isethionic acid and 3-oxy-propanesulfonic acid.

  The aliphatic sulfonic acid may be a sulfoaliphatic carboxylic acid, and specific examples of the sulfoaliphatic carboxylic acid include sulfoacetic acid and sulfosuccinic acid.

  The aliphatic sulfonic acid may be a sulfoaliphatic carboxylic acid ester, and specific examples of the sulfoaliphatic carboxylic acid ester include di (2-ethylhexyl) sulfosuccinic acid.

  The aliphatic sulfonic acid may be fluorosulfonic acid, and specific examples of the fluorosulfonic acid include trifluoromethanesulfonic acid, perfluoroethanesulfonic acid, perfluoropropanesulfonic acid, perfluoroisopropylsulfonic acid, perfluorobutanesulfonic acid. Acid, perfluoroisobutylsulfonic acid, perfluoro-tert-butylsulfonic acid, perfluoropentanesulfonic acid, perfluoroisopentylsulfonic acid, perfluorohexanesulfonic acid, perfluorononanesulfonic acid, perfluorodecanesulfonic acid, perfluoro Undecanesulfonic acid, perfluorododecanesulfonic acid, perfluorotridecanesulfonic acid, perfluorotetradecanesulfonic acid, perfluoro-n-octylsulfonic acid, perfluoro Dodecyl sulfonic acid and perfluorosulfonic cetyl sulfonic acid.

  Among aromatic sulfonic acids, specific examples of monovalent aromatic sulfonic acids include benzenesulfonic acid, p-toluenesulfonic acid, o-toluenesulfonic acid, m-toluenesulfonic acid, o-xylene-4-sulfonic acid. M-xylene-4-sulfonic acid, 4-ethylbenzenesulfonic acid, 4-propylbenzenesulfonic acid, 4-butylbenzenesulfonic acid, 4-dodecylbenzenesulfonic acid, 4-octylbenzenesulfonic acid, 2-methyl-5- Examples include isopropylbenzenesulfonic acid, 2-naphthalenesulfonic acid, butylnaphthalenesulfonic acid, t-butylnaphthalenesulfonic acid, 2,4,5-trichlorobenzenesulfonic acid, benzylsulfonic acid, and phenylethanesulfonic acid.

  Among aromatic sulfonic acids, specific examples of di- or higher valent aromatic sulfonic acids include m-benzenedisulfonic acid, 1,4-naphthalenedisulfonic acid, 1,5-naphthalenedisulfonic acid, 1,6-naphthalenedisulfonic acid. 2,6-naphthalenedisulfonic acid, 2,7-naphthalenedisulfonic acid, 1,3,6-naphthalenetrisulfonic acid, sulfonated polystyrene, and the like.

  The aromatic sulfonic acid may be an oxyaromatic sulfonic acid. Specific examples of the oxyaromatic sulfonic acid include phenol-2-sulfonic acid, phenol-3-sulfonic acid, phenol-4-sulfonic acid, anisole- o-sulfonic acid, anisole-m-sulfonic acid, phenetol-o-sulfonic acid, phenetol-m-sulfonic acid, phenol-2,4-disulfonic acid, phenol-2,4,6-trisulfonic acid, anisole-2 , 4-disulfonic acid, phenetole-2,5-disulfonic acid, 2-oxytoluene-4-sulfonic acid, pyrocatechin-4-sulfonic acid, veratrol-4-sulfonic acid, resorcin-4-sulfonic acid, 2-oxy -1-methoxybenzene-4-sulfonic acid, 1,2-dioxybenzene-3,5-disulfonic acid, reso Shin-4,6-disulfonic acid, hydroquinone sulfonic acid, hydroquinone-2,5-disulfonic acid and 1,2,3-oxybenzene-4-sulfonic acid and the like.

  The aromatic sulfonic acid may be a sulfoaromatic carboxylic acid. Specific examples of the sulfoaromatic carboxylic acid include o-sulfobenzoic acid, m-sulfobenzoic acid, p-sulfobenzoic acid, and 2,4-disulfo. Benzoic acid, 3-sulfophthalic acid, 3,5-disulfophthalic acid, 4-sulfoisophthalic acid, 2-sulfoterephthalic acid, 2-methyl-4-sulfobenzoic acid, 2-methyl-3,5-disulfobenzoic acid, 4 -Propyl-3-sulfobenzoic acid, 2,4,6-trimethyl-3-sulfobenzoic acid, 2-methyl-5-sulfoterephthalic acid, 5-sulfosalicylic acid and 3-oxy-4-sulfobenzoic acid It is done.

  The aromatic sulfonic acid may be a thioaromatic sulfonic acid. Specific examples of the thioaromatic sulfonic acid include thiophenol sulfonic acid, thioanisole-4-sulfonic acid, and thiophenetol-4-sulfonic acid. Can be mentioned.

  Among the aromatic sulfonic acids, specific examples having other functional groups include benzaldehyde-o-sulfonic acid, benzaldehyde-2,4-disulfonic acid, acetophenone-o-sulfonic acid, acetophenone-2,4-disulfonic acid, benzophenone. -O-sulfonic acid, benzophenone-3,3'-disulfonic acid, 4-aminophenol-3-sulfonic acid, anthraquinone-1-sulfonic acid, anthraquinone-2-sulfonic acid, anthraquinone-1,5-disulfonic acid, anthraquinone Examples include -1,8-disulfonic acid, anthraquinone-2,6-disulfonic acid, and 2-methylanthraquinone-1-sulfonic acid.

  Among the above sulfonic acids, monovalent aromatic sulfonic acid is preferably used, and specifically, benzenesulfonic acid, p-toluenesulfonic acid, o-toluenesulfonic acid and m-toluenesulfonic acid are preferably used.

  Specific examples of phenols containing one active hydrogen per molecule include phenol, cresol, ethylphenol, n-propylphenol, isopropylphenol, n-butylphenol, sec-butylphenol, and tert-butylphenol. Cyclohexylphenol, dimethylphenol, methyl-tert-butylphenol, di-tert-butylphenol, chlorophenol, bromophenol, nitrophenol, methoxyphenol, and methyl salicylate.

  Specific examples of phenols containing two active hydrogens in one molecule include hydroquinone, resorcinol, catechol, methylhydroquinone, tert-butylhydroquinone, benzylhydroquinone, phenylhydroquinone, dimethylhydroquinone, methyl-tert-butylhydroquinone, di- -Tert-butylhydroquinone, trimethylhydroquinone, methoxyhydroquinone, methylresorcinol, tert-butylresorcinol, benzylresorcinol, phenylresorcinol, dimethylresorcinol, methyl-tert-butylresorcinol, di-tert-butylresorcinol, trimethylresorcinol, methoxyresorcinol, methyl Catechol, tert-butylcatechol, benzylcatechol, phenylcatechol , Dimethylcatechol, methyl-tert-butylcatechol, di-tert-butylcatechol, trimethylcatechol, methoxycatechol, biphenol, 4,4′-dihydroxy-3,3 ′, 5,5′-tetramethylbiphenyl, 4 Biphenols such as 4,4′-dihydroxy-3,3 ′, 5,5′-tetra-tert-butylbiphenyl, bisphenol A, 4,4′-dihydroxy-3,3 ′, 5,5′-tetramethylbisphenol A, 4,4′-dihydroxy-3,3 ′, 5,5′-tetra-tert-butylbisphenol A, bisphenol F, 4,4′-dihydroxy-3,3 ′, 5,5′-tetramethylbisphenol F, 4,4′-dihydroxy-3,3 ′, 5,5′-tetra-tert-butylbispheno F, bisphenol AD, 4,4′-dihydroxy-3,3 ′, 5,5′-tetramethylbisphenol AD, 4,4′-dihydroxy-3,3 ′, 5,5′-tetra-tert-butyl Bisphenol AD is mentioned.

Further, as phenols containing two active hydrogens in one molecule, the following structural formula (XI),

Structural formula (XII),

Structural formula (XIII),

Structural formula (XIV),

Structural formula (XV),

Structural formula (XVI),

Or structural formula (XVII)

Bisphenols represented by terpene phenol, structural formula (XVIII)

で示される化合物等が挙げられる。１分子中に３個の活性水素を含むフェノール類の具体例としては、トリヒドロキシベンゼンおよびトリス（ｐ−ヒドロキシフェニル）メタン等が挙げられる。１分子中に４個の活性水素を含むフェノール類の具体例として、テトラキス（ｐ−ヒドロキシフェニル）エタン等が挙げられる。また、それ以外の具体例として、フェノール、アルキルフェノールおよびハロゲン化フェノール等とホルムアルデヒドとの反応により得られるフェノールノボラックが挙げられる。 Structural formula (XIX)

And the like. Specific examples of phenols containing three active hydrogens in one molecule include trihydroxybenzene and tris (p-hydroxyphenyl) methane. Specific examples of phenols containing 4 active hydrogens in one molecule include tetrakis (p-hydroxyphenyl) ethane. Other specific examples include phenol novolac obtained by reaction of phenol, alkylphenol, halogenated phenol, and the like with formaldehyde.

  Of the above phenols, phenol and phenol novolac are preferably used.

  Examples of alcohols include those containing two hydroxyl groups in one molecule, such as 1,2-ethanediol, 1,2-propanediol, 1,3-propanediol, 1,3-butane. Diol, 1,4-butanediol, 1,5-pentanediol, 1,1-dimethyl-1,3-propanediol, 2,2-dimethyl-1,3-propanediol, 2-methyl-2,4- Pentanediol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, diethylene glycol, triethylene glycol, dodecahydrobisphenol A, structural formula (XX)

で表されるビスフェノールＡのエチレンオキサイド付加物、構造式（ＸＸＩ）

An ethylene oxide adduct of bisphenol A represented by the structural formula (XXI)

で表されるビスフェノールＡのプロピレンオキサイド付加物、構造式（ＸＸＩＩ）

A propylene oxide adduct of bisphenol A represented by the structural formula (XXII)

で表されるドデカヒドロビスフェノールＡのエチレンオキサイド付加物、構造式（ＸＸＩＩＩ）

An ethylene oxide adduct of dodecahydrobisphenol A represented by the structural formula (XXIII)

で表されるドデカヒドロビスフェノールＡのプロピレンオキサイド付加物、グリセリン、トリメチロールエタンおよびトリメチロールプロパン等が挙げられる。また、１分子中に４個の水酸基を含むアルコール類の具体例としては、ペンタエリスリトール等が挙げられる。

And propylene oxide adducts of dodecahydrobisphenol A, glycerin, trimethylolethane, and trimethylolpropane. In addition, specific examples of alcohols containing four hydroxyl groups in one molecule include pentaerythritol.

  Examples of mercaptans include mercaptans containing one active hydrogen in one molecule. For example, methanethiol, ethanethiol, 1-propanethiol, 2-propanethiol, 1-butanethiol, 2-methyl -1-propanethiol, 2-butanethiol, 2-methyl-2-propanethiol, 1-pentanethiol, 1-hexanethiol, 1-heptanethiol, 1-octanethiol, cyclopentanethiol, cyclohexanethiol, benzyl mercaptan, Examples include benzene thiol, toluene thiol, chlorobenzene thiol, bromobenzene thiol, nitrobenzene thiol and methoxybenzene thiol.

  Specific examples of mercaptans containing two active hydrogens in one molecule include 1,2-ethanedithiol, 1,3-propanedithiol, 1,4-butanedithiol, 1,5-pentanedithiol, 2,2 '-Oxydiethanethiol, 1,6-hexanedithiol, 1,2-cyclohexanedithiol, 1,3-cyclohexanedithiol, 1,4-cyclohexanedithiol, 1,2-benzenedithiol, 1,3-benzenedithiol and 1 , 4-benzenethiol and the like.

  Examples of 1,3-dicarbonyl compounds include 2,4-pentanedione, 3-methyl-2,4-pentanedione, 3-ethyl-2,4-pentanedione, 3,5-heptanedione, 4 , 6-nonanedione, 2,6-dimethyl-3,5-heptanedione, 2,2,6,6-tetramethyl-3,5-heptanedione, 1-phenyl-1,3-butanedione, 1,3- Diphenyl-1,3-propanedione, 1,3-cyclopentanedione, 2-methyl-1,3-cyclopentanedione, 2-ethyl-1,3-cyclopentanedione, 1,3-cyclohexanedione, 2- Examples include methyl-1,3-cyclohexanedione, 2-ethyl-cyclohexanedione, 1,3-indandione, ethyl acetoacetate and diethyl malonate.

  The tertiary amine compound and / or tertiary amine salt (B1) having a molecular weight of 100 g / mol or more used in the present invention has the following general formula (III)

(In the formula, R ₈ represents a hydrocarbon group having 1 to 22 carbon atoms, and the hydrocarbon group may have a hydroxyl group, and the CH ₂ group in the hydrocarbon group represents —O—, —O, R ₉ may be any one of an alkylene group having 2 to 22 carbon atoms, an alkenylene group having 2 to 22 carbon atoms, or an alkynylene group having 2 to 22 carbon atoms, which may be substituted with —CO— or —CO—O—. R ₁₀ represents hydrogen or a hydrocarbon group having 1 to 22 carbon atoms, and the hydrocarbon group may have a hydroxyl group, and the CH ₂ group in the hydrocarbon group is —O— , -O-CO- or -CO-O-, or R ₈ and R ₁₀ may combine to form an alkylene group having 2 to 11 carbon atoms), Formula (IV)

(In the formula, R _{11 to} R ₁₃ each represent a hydrocarbon group having 1 to 22 carbon atoms, and the hydrocarbon group may have a hydroxyl group, and the CH ₂ group in the hydrocarbon group is- Optionally substituted by O-, -O-CO- or -CO-O-), the following general formula (V)

(In the formula, each of R _{14 to} R ₁₇ represents a hydrocarbon group having 1 to 22 carbon atoms, and the hydrocarbon group may have a hydroxyl group, and the CH ₂ group in the hydrocarbon group is- Optionally substituted by O-, -O-CO- or -CO-O-) or the following general formula (VI)

(In the formula, R _{18 to} R ₂₃ each represent a hydrocarbon group having 1 to 22 carbon atoms, and the hydrocarbon group may have a hydroxyl group, and the CH ₂ group in the hydrocarbon group is- It may be substituted by O-, -O-CO- or -CO-O- R ₂₄ represents a hydroxyl group or a hydrocarbon group having 1 to 22 carbon atoms, and the hydrocarbon group has a hydroxyl group. And the CH ₂ group in the hydrocarbon group may be substituted by —O—, —O—CO—, or —CO—O—), the general formula (VII)

（式中、Ｒ_２５〜Ｒ_２７は、それぞれ炭素数１〜８の炭化水素基を表し、該炭化水素基は水酸基を有していてもよい）、および一般式（ＶＩＩＩ）

(Wherein R _{25 to} R ₂₇ each represent a hydrocarbon group having 1 to 8 carbon atoms, and the hydrocarbon group may have a hydroxyl group), and general formula (VIII)

（式中、Ｒ_２８は、炭素数１〜８の炭化水素基を表し、該炭化水素基は水酸基を有していてもよい）からなる群から選択されるいずれか１つの３級アミン化合物および／または３級アミン塩であることが好ましい。

(Wherein R ₂₈ represents a hydrocarbon group having 1 to 8 carbon atoms, and the hydrocarbon group may have a hydroxyl group), and any one tertiary amine compound selected from the group consisting of A tertiary amine salt is preferred.

In the above general formulas (III) to (VI) of the present invention, R ₈ and R _{11 to} R ₂₃ each represent a hydrocarbon group having 1 to 22 carbon atoms, and the hydrocarbon group may have a hydroxyl group. The CH ₂ group in the hydrocarbon group may be substituted by —O—, —O—CO— or —CO—O—. By setting the number of carbon atoms to be between 1 and 22, the steric hindrance of the molecular structure is moderately small, the reaction promoting effect is increased, and the adhesion is improved. More preferably, it exists in the range of 1-14, More preferably, it exists in the range of 1-8. On the other hand, when the number of carbon atoms exceeds 22, the steric hindrance of the molecular structure may be somewhat large and the reaction promoting effect may be reduced.

R _{24 in the} general formula (VI) of the present invention is a hydroxyl group or a hydrocarbon group having 1 to 22 carbon atoms, and the hydrocarbon group may have a hydroxyl group, and CH in the hydrocarbon group _Two groups may be substituted by -O-, -O-CO- or -CO-O-. By setting the number of carbon atoms to be between 1 and 22, the steric hindrance of the molecular structure is moderately small, the reaction promoting effect is increased, and the adhesion is improved. More preferably, it exists in the range of 1-14, More preferably, it exists in the range of 1-8. On the other hand, when the number of carbon atoms exceeds 22, the steric hindrance of the molecular structure may be somewhat large and the reaction promoting effect may be reduced.

R _{9 in the} general formula (III) of the present invention represents any of an alkylene group having 2 to 22 carbon atoms, an alkenylene group having 2 to 22 carbon atoms, or an alkynylene group having 2 to 22 carbon atoms. By setting the number of carbon atoms to between 2 and 22, the steric hindrance of the molecular structure is moderately small, the reaction promoting effect is increased, and the adhesion is improved. Preferably it exists in the range of 3-22, More preferably, it exists in the range of 3-14, More preferably, it exists in the range of 3-8. On the other hand, when the number of carbon atoms exceeds 22, the steric hindrance of the molecular structure may be somewhat large and the reaction promoting effect may be reduced.

R _{10 in} the above general formula (III) of the present invention is hydrogen or a hydrocarbon group having 1 to 22 carbon atoms, and the hydrocarbon group may have a hydroxyl group, and CH ₂ in the hydrocarbon group. The group may be substituted by -O-, -O-CO- or -CO-O-. By setting the number of carbon atoms to be between 1 and 22, the steric hindrance of the molecular structure is moderately small, the reaction promoting effect is increased, and the adhesion is improved. More preferably, it exists in the range of 1-14, More preferably, it exists in the range of 1-8. On the other hand, when the number of carbon atoms exceeds 22, the steric hindrance of the molecular structure may be somewhat large and the reaction promoting effect may be reduced.

  Here, a C1-C22 hydrocarbon group is a group which consists only of a carbon atom and a hydrogen atom, and any of a saturated hydrocarbon group and an unsaturated hydrocarbon group may be included, even if it contains a ring structure. Also good. As the hydrocarbon group, for example, methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, cyclohexyl group, octyl group, decyl group, dodecyl group, tetradecyl group, hexadecyl group, octadecyl group, oleyl group, A docosyl group, a benzyl group, a phenyl group, etc. are mentioned.

Further, the hydrocarbon group having 1 to 22 carbon atoms may be one in which a CH ₂ group in the hydrocarbon group is substituted with —O—. Examples of the case where the CH ₂ group in the hydrocarbon group having 1 to 22 carbon atoms is substituted by —O— include, for example, a straight chain, such as a methoxymethyl group, an ethoxymethyl group, a propoxymethyl group, butoxy Polyether groups such as methyl group, phenoxymethyl group, methoxyethyl group, ethoxyethyl group, propoxyethyl group, butoxyethyl group, phenoxyethyl group, methoxyethoxymethyl group, methoxyethoxyethyl group, polyethylene glycol group and polypropylene glycol group Can be mentioned. Examples of cyclic compounds include ethylene oxide, tetrahydrofuran, oxepane, and 1,3-dioxolane.

Further, the hydrocarbon group having 1 to 22 carbon atoms may be one in which a CH ₂ group in the hydrocarbon group is substituted by —O—CO— or —CO—O—. Examples of the case where the CH ₂ group in the hydrocarbon group having 1 to 22 carbon atoms is substituted by —O—CO— or —CO—O— include, for example, an acetoxymethyl group, an acetoxyethyl group, an acetoxypropyl group, Examples include an acetoxybutyl group, a methacryloyloxyethyl group, a benzoyloxyethyl group, a methoxycarbonyl group, and an ethoxycarbonyl group.

  The hydrocarbon group having 1 to 22 carbon atoms may have a hydroxyl group, and examples of the case where the hydrocarbon group having 1 to 22 carbon atoms has a hydroxyl group include, for example, a hydroxymethyl group and a hydroxyethyl group. , Hydroxypropyl group, hydroxybutyl group, hydroxypentyl group, hydroxyhexyl group, hydroxycyclohexyl group, hydroxyoctyl group, hydroxydecyl group, hydroxydodecyl group, hydroxytetradecyl group, hydroxyhexadecyl group, hydroxyoctadecyl group, hydroxyoleyl group And a hydroxydocosyl group and the like.

  In the present invention, the tertiary amine compound (B1) preferably has an acid dissociation constant pKa of the conjugate acid of 9 or more, more preferably 11 or more. When the acid dissociation constant pKa is 9 or more, the component (B1) can easily extract hydrogen ions from oxygen-containing functional groups such as a carboxyl group and a hydroxyl group of the carbon fiber, so the functional group on the surface of the carbon fiber and the epoxy of the component (A) The reaction with the group is promoted, and the effect of improving adhesion is increased. Specific examples of such tertiary amine compounds include DBU (pKa12.5), DBN (pKa12.7), 1,8-bis (dimethylamino) naphthalene (pKa12.3), and the like.

  In the present invention, the tertiary amine compound and / or tertiary amine salt (B1) preferably has a boiling point of 160 ° C. or higher, more preferably in the range of 160 to 350 ° C., and still more preferably 160 to 260. Within the range of ° C. When the boiling point is less than 160 ° C., the volatilization becomes intense in the step of heat treatment for 30 to 600 seconds in the temperature range of 160 to 260 ° C., and the reaction promoting effect may be reduced.

  The tertiary amine compound (B1) and / or tertiary amine salt used in the present invention includes aliphatic tertiary amines, aromatic-containing aliphatic tertiary amines, aromatic tertiary amines and heterocyclic rings. Formula tertiary amines and their salts. Next, a specific example is given.

  Specific examples of the aliphatic tertiary amines include, for example, triethylamine, tripropylamine, triisopropylamine, tributylamine, tripentylamine, trihexylamine, tricyclohexylamine, trioctylamine, dimethylpropylamine, dimethylbutylamine, Dimethylpentylamine, dimethylhexylamine, dimethylcyclohexylamine, dimethyloctylamine, dimethyldecylamine, dimethyldodecylamine, dimethyltetradecylamine, dimethylhexadecylamine, dimethyloctadecylamine, dimethyloleylamine, dimethyldocosylamine, diethylpropylamine, Diethylbutylamine, diethylpentylamine, diethylhexylamine, diethylcyclohexylamine, diethyl Octylamine, diethyldecylamine, diethyldodecylamine, diethyltetradecylamine, diethylhexadecylamine, diethyloctadecylamine, diethyloleylamine, diethyldocosylamine, dipropylmethylamine, diisopropylethylamine, dipropylethylamine, dipropylbutylamine, dibutyl Methylamine, dibutylethylamine, dibutylpropylamine, dihexylmethylamine, dihexylmethylamine, dihexylpropylamine, dihexylbutylamine, dicyclohexylmethylamine, dicyclohexylethylamine, dicyclohexylpropylamine, dicyclohexylbutylamine, dioctylmethylamine, dioctylethylamine, dioctylpropylamine, Didecyl Tylamine, didecylethylamine, didecylpropylamine, didecylbutylamine, didodecylmethylamine, didodecylethylamine, didodecylpropylamine, didodecylbutylamine, ditetradecylmethylamine, ditetradecylethylamine, ditetradecylpropylamine, Ditetradecylbutylamine, dihexadecylmethylamine, dihexadecylethylamine, dihexadecylpropylamine, dihexadecylbutylamine, trimethanolamine, triethanolamine, triisopropanolamine, tributanolamine, trihexanolamine, diethylmethanolamine , Dipropylmethanolamine, diisopropylmethanolamine, dibutylmethanolamine, diisobutylmethanolamine, Ditertiarybutylmethanolamine, di (2-ethylhexyl) methanolamine, dimethylethanolamine, diethylethanolamine, dipropylethanolamine, diisopropylethanolamine, dibutylethanolamine, diisobutylethanolamine, ditertiarybutylethanolamine, di (2- Ethylhexyl) ethanolamine, dimethylpropanolamine, diethylpropanolamine, dipropylpropanolamine, diisopropylpropanolamine, dibutylpropanolamine, diisobutylpropanolamine, ditertiarybutylpropanolamine, di (2-ethylhexyl) propanolamine, methyldimethanolamine, Ethyldimethanolamine, propyldimethanolamine, Sopropyldimethanolamine, butyldimethanolamine, isobutyldimethanolamine, tertiarybutyldimethanolamine, (2-ethylhexyl) dimethanolamine, methyldiethanolamine, ethyldiethanolamine, propyldiethanolamine, isopropyldiethanolamine, butyldiethanolamine, isobutyldiethanolamine, Tertiary butyl diethanolamine, (2-ethylhexyl) diethanolamine, dimethylaminoethoxyethanol, etc. are mentioned.

  Aliphatic tertiary amines may be compounds having two or more tertiary amino groups in the molecule, and compounds having two or more tertiary amino groups in the molecule include N, N, N ′, N′-tetramethyl-1,3-propanediamine, N, N, N ′, N′-tetraethyl-1,3-propanediamine, N, N-diethyl-N ′, N′-dimethyl-1,3- Examples include propanediamine, tetramethyl-1,6-hexamethylenediamine, pentamethyldiethylenetriamine, bis (2-dimethylaminoethyl) ether, and trimethylaminoethylethanolamine.

  Specific examples of aromatic-containing aliphatic tertiary amines include, for example, N, N-dimethylbenzylamine, N, N-diethylbenzylamine, N, N-dipropylbenzylamine, N, N′-dibutylbenzylamine N, N-dihexylbenzylamine, N, N-dicyclohexylbenzylamine, N, N-dioctylbenzylamine, N, N-didodecylbenzylamine, N, N-dioleylbenzylamine, N, N-dibenzylmethyl Amine, N, N-dibenzylethylamine, N, N-dibenzylpropylamine, N, N-dibenzylbutylamine, N, N-dibenzylhexylamine, N, N-dibenzylcyclohexylamine, N, N-di Benzyloctylamine, N, N-dibenzyldodecylamine, N, N-dibenzyloleylamine Tribenzylamine, N, N-methylethylbenzylamine, N, N-methylpropylbenzylamine, N, N-methylbutylbenzylamine, N, N-methylhexylbenzylamine, N, N-methylcyclohexylbenzylamine, N , N-methyloctylbenzylamine, N, N-methyldodecylbenzylamine, N, N-methyloleylbenzylamine, N, N-methylhexadecylbenzylamine, N, N-methyloctadecylbenzylamine, 2- (dimethylamino) Methyl) phenol, 2,4,6-tris (dimethylaminomethyl) phenol, 2,4,6-tris (diethylaminomethyl) phenol, 2,4,6-tris (dipropylaminomethyl) phenol, 2,4, 6-Tris (dibutylaminomethyl) pheno , 2,4,6-tris (dipentylamino methyl) phenol, and 2,4,6-tris (dihexyl aminomethyl) phenol and the like.

  Specific examples of aromatic tertiary amines include, for example, triphenylamine, tri (methylphenyl) amine, tri (ethylphenyl) amine, tri (propylphenyl) amine, tri (butylphenyl) amine, tri (phenoxyphenyl) ) Amine, tri (benzylphenyl) amine, diphenylmethylamine, diphenylethylamine, diphenylpropylamine, diphenylbutylamine, diphenylhexylamine, diphenylcyclohexylamine, N, N-dimethylaniline, N, N-diethylaniline, N, N- Dipropylaniline, N, N-dibutylaniline, N, N-dihexylaniline, N, N-dicyclohexylaniline, (methylphenyl) dimethylamine, (ethylphenyl) dimethylamine, (propylphenyl) dimethylamine, (butylphenyl) Nyl) dimethylamine, bis (methylphenyl) methylamine, bis (ethylphenyl) methylamine, bis (propylphenyl) methylamine, bis (butylphenyl) methylamine, N, N-di (hydroxyethyl) aniline, N, Examples include N-di (hydroxypropyl) aniline, N, N-di (hydroxybutyl) aniline, and diisopropanol-p-toluidine.

  Specific examples of the heterocyclic tertiary amines include, for example, pyridine compounds such as picoline, isoquinoline and quinoline, imidazole compounds, pyrazole compounds, morpholine compounds, piperazine compounds, piperidine compounds, pyrrolidine compounds, Examples include cycloamidine compounds, proton sponge derivatives, and hindered amine compounds.

  Examples of the pyridine compound include N, N-dimethyl-4-aminopyridine, bipyridine, and 2,6-lutidine. Examples of imidazole compounds include 1-benzyl-2-methylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-ethyl-4-imidazole, 1-cyanoethyl-2. -Undecylimidazole, 1-cyanoethyl-2-methylimidazolium trimellitate, 1-cyanoethyl-2-undecylimidazolium trimellitate, 1-benzyl-2-phenylimidazole, 1- (2-hydroxyethyl) imidazole 1-benzyl-2-formylimidazole, 1-benzyl-imidazole, 1-allylimidazole and the like.

  Examples of pyrazole compounds include pyrazole and 1,4-dimethylpyrazole. Examples of the morpholine compound include 4- (2-hydroxyethyl) morpholine, N-ethylmorpholine, N-methylmorpholine, and 2,2'-dimorpholine diethyl ether. Examples of piperazine compounds include 1- (2-hydroxyethyl) piperazine and N, N-dimethylpiperazine. Examples of piperidine compounds include N- (2-hydroxyethyl) piperidine, N-ethylpiperidine, N-propylpiperidine, N-butylpiperidine, N-hexylpiperidine, N-cyclohexylpiperidine and N-octylpiperidine. Examples of the pyrrolidine compound include N-butylpyrrolidine and N-octylpyrrolidine. Examples of the cycloamidine compounds include 1,8-diazabicyclo [5,4,0] -7-undecene (DBU), 1,5-diazabicyclo [4,3,0] -5-nonene (DBN), 1,4. -Diazabicyclo [2.2.2] octane and 5,6-dibutylamino-1,8-diaza-bicyclo [5,4,0] undecene-7 (DBA). Examples of other heterocyclic amines include hexamethylenetetramine, hexaethylenetetramine, and hexapropyltetramine.

  Specific examples of the DBU salt include DBU phenol salt (U-CAT SA1, manufactured by San Apro Corporation), DBU octylate (U-CAT SA102, manufactured by San Apro Corporation), DBU p-toluene. Sulfonate (U-CAT SA506, manufactured by San Apro Co., Ltd.), DBU formate (U-CAT SA603, manufactured by San Apro Co., Ltd.), DBU orthophthalate (U-CAT SA810), and DBU phenol novolac resin salt (U-CAT SA810, SA831, SA841, SA851, 881, manufactured by San Apro Corporation) and the like.

  Specific examples of the proton sponge derivative include 1,8-bis (dimethylamino) naphthalene, 1,8-bis (diethylamino) naphthalene, 1,8-bis (dipropylamino) naphthalene, 1,8- Bis (dibutylamino) naphthalene, 1,8-bis (dipentylamino) naphthalene, 1,8-bis (dihexylamino) naphthalene, 1-dimethylamino-8-methylamino-quinolidine, 1-dimethylamino-7-methyl- 8-methylamino-quinolidine, 1-dimethylamino-7-methyl-8-methylamino-isoquinoline, 7-methyl-1,8-methylamino-2,7-naphthyridine, and 2,7-dimethyl-1,8 -Methylamino-2,7-naphthyridine and the like.

  Examples of the hindered amine compound include tetrakis butane-1,2,3,4-tetracarboxylate (1,2,2,6,6-pentamethyl-4-piperidinyl) (for example, LA-52 (manufactured by ADEKA)). ), Bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate (for example, LA-72 (manufactured by ADEKA), TINUVIN765 (manufactured by BASF)), carbonic acid = bis (2,2, 6,6-tetramethyl-1-undecyloxypiperidin-4-yl) (for example, LA-81 (manufactured by ADEKA)), methacrylic acid-1,2,2,6,6-pentamethyl-4-piperidyl ( For example, LA-82 (manufactured by ADEKA)), malonic acid-2-((4-methoxyphenyl) methylene), 1,3-bis (1,2,2,6,6-pentamethyl-4- Peridinyl) ester, Chimassorb 119, 2-dodecyl-N- (1,2,2,6,6-pentamethyl-4-piperidinyl) succin-imide, 1,2,3,4-butanetetracarboxylic acid-1-hexadecyl- 2,3,4-tris (1,2,2,6,6-pentamethyl-4-piperidinyl), 1,2,3,4-butanetetracarboxylic acid-1,2,3-tris (1,2, 2,6,6-pentamethyl-4-piperidinyl) -4-tridecyl, decanedioic acid-1-methyl-10- (1,2,2,6,6-pentamethyl-4-piperidinyl), 4- (ethenyloxy) -1,2,2,6,6-pentamethylpiperidine, 2-((3,5-bis (1,1-dimethylethyl) -4-hydroxyphenyl) methyl) -2-butylpropanedioic acid bis 1,2,2,6,6-pentamethyl-4-piperidinyl), 4-hydroxy-1,2,2,6,6-pentamethylpiperidine, 1,2,2,6,6-pentamethylpiperidine, LA -63P (made by ADEKA), LA-68 (made by ADEKA), TINUVIN622LD (made by BASF), TINUVIN144 (made by BASF), etc. are mentioned.

  These tertiary amine compounds and tertiary amine salts may be used alone or in combination of two or more.

The number of carbon atoms of at least one of R _{11 to} R _{13 in} the general formula (IV) of the present invention is preferably 2 or more, more preferably 3 or more, and further preferably 4 or more. When at least one carbon number of R _{11 to} R ₁₃ is 2 or more, a side reaction in which a tertiary amine compound and / or a tertiary amine salt works as an initiator, for example, homopolymerization of an epoxy resin is suppressed, Adhesion is further improved.

  In the present invention, the compound represented by the general formula (III) is N-benzylimidazole, 1,8-diazabicyclo [5,4,0] -7-undecene (DBU) and a salt thereof, or 1,5 -Diazabicyclo [4,3,0] -5-nonene (DBN) and salts thereof are preferred, 1,8-diazabicyclo [5,4,0] -7-undecene (DBU) and salts thereof, or 1,5 -Diazabicyclo [4,3,0] -5-nonene (DBN) and its salts are preferred.

  In the present invention, the compound represented by the general formula (IV) is tributylamine or N, N-dimethylbenzylamine, diisopropylethylamine, triisopropylamine, dibutylethanolamine, diethylethanolamine, triisopropanolamine, triethanolamine. N, N-diisopropylethylamine is preferred.

  In the present invention, the compound represented by the general formula (V) is preferably 1,8-bis (dimethylamino) naphthalene.

  In the present invention, the compound represented by the general formula (VI) is preferably 2,4,6-tris (dimethylaminomethyl) phenol.

In the present invention, the compound represented by the general formula (VII) is preferably 2,6-lutidine or 4-pyridinemethanol.
In the present invention, the compound represented by the general formula (VIII) is preferably N-ethylmorpholine.

  Among these tertiary amine compounds and tertiary amine salts, triisopropylamine and dibutylethanol are preferred because they have a high effect of promoting the reaction between the functional group on the surface of the carbon fiber and the epoxy resin and can suppress the reaction between the epoxy rings. Amine, diethylethanolamine, triisopropanolamine, diisopropylethylamine, 2,4,6-tris (dimethylaminomethyl) phenol, 2,6-lutidine, DBU, DBU salt, DBN, DBN salt and 1,8-bis (dimethyl) Amino) naphthalene is preferably used.

  Next, (B2) will be described.

  (B2) The quaternary ammonium salt having a cation moiety represented by any one of the above general formulas (I) and (II) used in the present invention has a ratio of 0. It is necessary to mix 1 to 25 parts by mass, preferably 0.1 to 10 parts by mass, and more preferably 0.1 to 8 parts by mass. When the blending amount is less than 0.1 part by mass, the formation of a covalent bond between (A) the epoxy compound and the oxygen-containing functional group on the surface of the carbon fiber is not promoted, and the adhesion between the carbon fiber and the matrix resin is poor. It will be enough. On the other hand, if the blending amount exceeds 25 parts by mass, (B2) covers the carbon fiber surface and the covalent bond formation is inhibited, and the adhesion between the carbon fiber and the matrix resin becomes insufficient.

(B2) used in the present invention The mechanism by which the covalent bond formation is promoted by the incorporation of the quaternary ammonium salt having a cation moiety represented by either the above general formula (I) or (II) is not clear. Such an effect can be obtained only with a quaternary ammonium salt having a specific structure. Therefore, R _{1 to} R ₅ in the above general formula (I) or (II) must each be a hydrocarbon group having 1 to 22 carbon atoms, and the hydrocarbon group may have a hydroxyl group. In addition, the CH ₂ group in the hydrocarbon group may be substituted by —O—, —O—CO— or —CO—O—. When the carbon number is 23 or more, the reason is not clear, but the adhesiveness is insufficient. Here, a C1-C22 hydrocarbon group is a group which consists only of a carbon atom and a hydrogen atom, and any of a saturated hydrocarbon group and an unsaturated hydrocarbon group may be included, even if it contains a ring structure. Also good. Examples of the hydrocarbon group include methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, cyclohexyl group, octyl group, decyl group, dodecyl group, tetradecyl group, hexadecyl group, octadecyl group, oleyl group, A docosyl group, a benzyl group, a phenyl group, etc. are mentioned.

Examples of the case where the CH ₂ group in the hydrocarbon group having 1 to 22 carbon atoms is substituted by —O— include, for example, methoxymethyl group, ethoxymethyl group, propoxymethyl group, butoxymethyl group, phenoxymethyl And polyether groups such as methoxyethyl group, ethoxyethyl group, propoxyethyl group, butoxyethyl group, phenoxyethyl group, methoxyethoxymethyl group, methoxyethoxyethyl group, polyethylene glycol group and polypropylene glycol group.

Examples of the case where the CH ₂ group in the hydrocarbon group having 1 to 22 carbon atoms is substituted by —O—CO— or —CO—O— include hydrocarbons having 1 to 22 carbon atoms and ester structures. Examples of the group to be included include an acetoxymethyl group, an acetoxyethyl group, an acetoxypropyl group, an acetoxybutyl group, a methacryloyloxyethyl group, a benzoyloxyethyl group, a methoxycarbonyl group, and an ethoxycarbonyl group.

  Examples of the case where the hydrocarbon group having 1 to 22 carbon atoms has a hydroxyl group include, for example, a hydroxymethyl group, a hydroxyethyl group, a hydroxypropyl group, a hydroxybutyl group, a hydroxypentyl group, a hydroxyhexyl group, and a hydroxycyclohexyl group. , Hydroxyoctyl group, hydroxydecyl group, hydroxydodecyl group, hydroxytetradecyl group, hydroxyhexadecyl group, hydroxyoctadecyl group, hydroxyoleyl group, hydroxydocosyl group and the like.

Especially, it is preferable that the carbon number of R < ₁ > -R < ₅ > of (B2) quaternary ammonium salt which has a cation part exists in the range of 1-14, More preferably, it exists in the range of 1-8. When the carbon number is less than 14, when the quaternary ammonium salt acts as a reaction accelerator, the steric hindrance is moderately small and the reaction promoting effect is enhanced, and the adhesion is further improved.

In the present invention, the number of carbon atoms of R ₃ and R _{4 in} the quaternary ammonium salt having a cation moiety (B2) represented by the general formula (I) is preferably 2 or more, more preferably 3 or more. More preferably, it is 4 or more. When the carbon number is 2 or more, homopolymerization of the epoxy resin due to the quaternary ammonium salt acting as an initiator is suppressed, and the adhesiveness is further improved.

In the present invention, R ₆ and R ₇ of the quaternary ammonium salt having a cation moiety (B2) represented by the general formula (II) are each hydrogen or a hydrocarbon group having 1 to 8 carbon atoms. And the CH ₂ group in the hydrocarbon group may be substituted by —O—, —O—CO— or —CO—O—. When hydrogen or the number of carbon atoms is less than 8, the ratio of active sites in the molecule is high, and a large adhesion improvement effect can be obtained even with a small amount.

  In the present invention, (B2) the molecular weight of the cation moiety of the quaternary ammonium salt having a cation moiety is preferably in the range of 100 to 400 g / mol, more preferably in the range of 100 to 300 g / mol. More preferably, it is in the range of 100 to 200 g / mol. When the molecular weight of the cation moiety is 100 g / mol or more, volatilization is suppressed even during the heat treatment, and a large adhesive improvement effect can be obtained even with a small amount. On the other hand, when the molecular weight of the cation moiety is 400 g / mol or less, the ratio of the active moiety in the molecule is high, and a large adhesion improvement effect can be obtained even with a small amount.

  In the present invention, examples of the cation moiety of the quaternary ammonium salt represented by the general formula (I) include tetramethylammonium, ethyltrimethylammonium, trimethylpropylammonium, butyltrimethylammonium, trimethylpentylammonium, hexyltrimethylammonium, Cyclohexyltrimethylammonium, trimethyloctylammonium, decyltrimethylammonium, dodecyltrimethylammonium, tetradecyltrimethylammonium, hexadecyltrimethylammonium, trimethyloctadecylammonium, trimethyloleylammonium, docosyltrimethylammonium, benzyltrimethylammonium, trimethylphenylammonium, diethyldimethylammonium Dimethyl, dimethyldipropylammonium, dibutyldimethylammonium, dimethyldipentylammonium, dihexyldimethylammonium, dicyclohexyldimethylammonium, dimethyldioctylammonium, didecyldimethylammonium, ethyldecyldimethylammonium, didodecyldimethylammonium, ethyldodecyldimethylammonium, ditetradecyl Dimethyl ammonium, ethyl tetradecyl dimethyl ammonium, dihexadecyl dimethyl ammonium, ethyl hexadecyl dimethyl ammonium, dimethyl dioctadecyl ammonium, ethyl octadecyl dimethyl ammonium, dimethyl dioleyl ammonium, ethyl dimethyl oleyl ammonium, didocosyl dimethyl ammonium, Silethyldimethylammonium, dibenzyldimethylammonium, benzylethyldimethylammonium, benzyldimethylpropylammonium, benzylbutyldimethylammonium, benzyldecyldimethylammonium, benzyldodecyldimethylammonium, benzyltetradecyldimethylammonium, benzylhexadecyldimethylammonium, benzyloctadecyldimethyl Ammonium, benzyldimethyloleylammonium, dimethyldiphenylammonium, ethyldimethylphenylammonium, dimethylpropylphenylammonium, butyldimethylphenylammonium, decyldimethylphenylammonium, dodecyldimethylphenylammonium, tetradecyldimethylphenylammonium , Hexadecyldimethylphenylammonium, dimethyloctadecylphenylammonium, dimethyloleylphenylammonium, tetraethylammonium, triethylmethylammonium, triethylpropylammonium, butyltriethylammonium, triethylpentylammonium, triethylhexylammonium, triethylcyclohexylammonium, triethyloctylammonium, decyl Triethylammonium, dodecyltriethylammonium, tetradecyltriethylammonium, hexadecyltriethylammonium, triethyloctadecylammonium, triethyloleylammonium, benzyltriethylammonium, triethylphenylammonium, diethyldipropylan Ni, dibutyl diethyl ammonium, diethyl dipentyl ammonium, diethyl dihexyl ammonium, diethyl dicyclohexyl ammonium, diethyl dioctyl ammonium, didecyl diethyl ammonium, didodecyl diethyl ammonium, ditetradecyl diethyl ammonium, diethyl dihexadecyl ammonium, diethyl dioctadecyl ammonium, diethyl Dioleylammonium, dibenzyldiethylammonium, diethyldiphenylammonium, tetrapropylammonium, methyltripropylammonium, ethyltripropylammonium, butyltripropylammonium, benzyltripropylammonium, phenyltripropylammonium, tetrabutylammonium, tributy Methylammonium, tributylethylammonium, tributylpropylammonium, benzyltributylammonium, tributylphenylammonium, tetrapentylammonium, tetrahexylammonium, tetraheptylammonium, tetraoctylammonium, methyltrioctylammonium, ethyltrioctylammonium, trioctylpropylammonium, Butyl trioctyl ammonium, dimethyl dioctyl ammonium, diethyl dioctyl ammonium, dioctyl dipropyl ammonium, dibutyl dioctyl ammonium, tetradecyl ammonium, tetradodecyl ammonium, 2-hydroxyethyl trimethyl ammonium, 2-hydroxyethyl triethyl ammonium, 2-hy Droxyethyltripropylammonium, 2-hydroxyethyltributylammonium, polyoxyethylenetrimethylammonium, polyoxyethylenetriethylammonium, polyoxyethylenetripropylammonium, polyoxyethylenetributylammonium, bis (2-hydroxyethyl) dimethylammonium, bis (2-hydroxyethyl) diethylammonium, bis (2-hydroxyethyl) dipropylammonium, bis (2-hydroxyethyl) dibutylammonium, bis (polyoxyethylene) dimethylammonium, bis (polyoxyethylene) diethylammonium, bis ( Polyoxyethylene) dipropylammonium, bis (polyoxyethylene) dibutylammonium, tris (2-hydride) Xylethyl) methylammonium, tris (2-hydroxyethyl) ethylammonium, tris (2-hydroxyethyl) propylammonium, tris (2-hydroxyethyl) butylammonium, tris (polyoxyethylene) methylammonium, tris (polyoxyethylene) Examples include ethylammonium, tris (polyoxyethylene) propylammonium, and tris (polyoxyethylene) butylammonium.

  Examples of the cation moiety of the quaternary ammonium salt represented by the general formula (II) include 1-methylpyridinium, 1-ethylpyridinium, 1-ethyl-2-methylpyridinium, and 1-ethyl-4-methylpyridinium. 1-ethyl-2,4-dimethylpyridinium, 1-ethyl-2,4,6-trimethylpyridinium, 1-propylpyridinium, 1-butylpyridinium, 1-butyl-2-methylpyridinium, 1-butyl-4- Methylpyridinium, 1-butyl-2,4-dimethylpyridinium, 1-butyl-2,4,6-trimethylpyridinium, 1-pentylpyridinium, 1-hexylpyridinium, 1-cyclohexylpyridinium, 1-octylpyridinium, 1-decyl Pyridinium, 1-dodecylpyridinium, - tetradecyl pyridinium, 1-hexadecyl pyridinium, 1-octadecyl pyridinium, 1-oleyl pyridinium, and 1-docosyl pyridinium, and 1-benzyl pyridinium and the like.

  In the present invention, examples of the anion moiety of the quaternary ammonium salt (B2) having a cation moiety include halogen ions of fluoride anion, chloride anion, bromide anion and iodide anion. Moreover, for example, a hydroxide anion, an acetate anion, an oxalate anion, a sulfate anion, a benzoate anion, an iodate anion, a methylsulfonate anion, a benzenesulfonate anion, and a toluenesulfonate anion are exemplified.

  Especially, as a counter ion, it is preferable that it is a halogen ion from a viewpoint that the size is small and it does not inhibit the reaction promotion effect of a quaternary ammonium salt.

  In the present invention, these quaternary ammonium salts may be used alone or in combination.

  In the present invention, (B2) the quaternary ammonium salt having a cation moiety includes, for example, trimethyloctadecylammonium chloride, trimethyloctadecylammonium bromide, trimethyloctadecylammonium hydroxide, trimethyloctadecylammonium acetate, trimethyloctadecylammonium benzoate, trimethyl Octadecylammonium-p-toluenesulfonate, trimethyloctadecylammonium hydrochloride, trimethyloctadecylammonium tetrachloroiodate, trimethyloctadecylammonium hydrogensulfate, trimethyloctadecylammonium methylsulfate, benzyltrimethylammonium chloride, benzyltrimethylammonium bromide, benzyltri Mechi Ammonium hydroxide, benzyltrimethylammonium acetate, benzyltrimethylammonium benzoate, benzyltrimethylammonium-p-toluenesulfonate, tetrabutylammonium chloride, tetrabutylammonium bromide, tetrabutylammonium hydroxide, tetrabutylammonium acetate, tetra Butylammonium benzoate, tetrabutylammonium-p-toluenesulfonate, (2-methoxyethoxymethyl) triethylammonium chloride, (2-methoxyethoxymethyl) triethylammonium bromide, (2-methoxyethoxymethyl) triethylammonium hydroxide, (2-Methoxyethoxymethyl) triethylammonium-p-toluenesulfonater (2-acetoxyethyl) trimethylammonium chloride, (2-acetoxyethyl) trimethylammonium bromide, (2-acetoxyethyl) trimethylammonium hydroxide, (2-acetoxyethyl) trimethylammonium-p-toluenesulfonate, (2- Hydroxyethyl) trimethylammonium chloride, (2-hydroxyethyl) trimethylammonium bromide, (2-hydroxyethyl) trimethylammonium hydroxide, (2-hydroxyethyl) trimethylammonium-p-toluenesulfonate, bis (polyoxyethylene) dimethyl Ammonium chloride, bis (polyoxyethylene) dimethylammonium bromide, bis (polyoxyethylene) dimethylammonium hydroxide, Bis (polyoxyethylene) dimethylammonium-p-toluenesulfonate, 1-hexadecylpyridinium chloride, 1-hexadecylpyridinium bromide, 1-hexadecylpyridinium hydroxide, 1-hexadecylpyridinium-p-toluenesulfonate, etc. Is mentioned.

  In the present invention, the compound represented by the general formula (I) includes benzyltrimethylammonium bromide, tetrabutylammonium bromide, trimethyloctadecylammonium bromide, (2-methoxyethoxymethyl) triethylammonium chloride, (2-acetoxyethyl) trimethyl. Ammonium chloride and (2-hydroxyethyl) trimethylammonium bromide are preferred, and tetrabutylammonium bromide and (2-methoxyethoxymethyl) triethylammonium chloride are preferred.

  In the present invention, the compound represented by the general formula (II) is preferably 1-hexadecylpyridinium chloride.

  Next, (B3) will be described.

  The (B3) quaternary phosphonium salt and / or phosphine compound used in the present invention needs to be blended in an amount of 0.1 to 25 parts by mass with respect to 100 parts by mass of the (A) epoxy compound. It is preferable to mix | blend 10 mass parts, and it is more preferable to mix | blend 0.1-8 mass parts. When the blending amount is less than 0.1 part by mass, the formation of a covalent bond between (A) the epoxy compound and the oxygen-containing functional group on the surface of the carbon fiber is not promoted, and the adhesion between the carbon fiber and the matrix resin is poor. It will be enough. On the other hand, if the blending amount exceeds 25 parts by mass, (B3) covers the carbon fiber surface, the covalent bond formation is inhibited, and the adhesion between the carbon fiber and the matrix resin becomes insufficient.

  The (B3) quaternary phosphonium salt or phosphine compound used in the present invention is preferably the following general formula (IX) or (X)

(In the above chemical formula, R _{29 to} R ₃₅ each represent a hydrocarbon group having 1 to 22 carbon atoms, the hydrocarbon group may have a hydroxyl group, and the CH ₂ group in the hydrocarbon group is A quaternary ammonium salt or a phosphine compound having a cation moiety represented by any one of -O-, -O-CO- and -CO-O-.

  The present inventors show (B3) a quaternary phosphonium salt and / or a phosphine compound, preferably any one of the above general formulas (IX) or (X) with respect to 100 parts by mass of the component (A) (B3 ) Bifunctional or higher only when a sizing agent containing 0.1 to 25 parts by mass of a quaternary phosphonium salt and / or a phosphine compound is applied to a carbon fiber and heat-treated under specific conditions. As a result of the promotion of covalent bond formation between the epoxy resin and the oxygen-containing functional groups such as carboxyl groups and hydroxyl groups that are originally contained on the carbon fiber surface or introduced by oxidation treatment, adhesion to the matrix resin It has been found that the performance is greatly improved.

In the present invention, the mechanism by which the formation of a covalent bond is promoted by the incorporation of a quaternary phosphonium salt or a phosphine compound is not clear, but the present invention is preferably used by using a quaternary phosphonium salt or phosphine compound having the specific structure. The effect is obtained. That is, as the (B3) quaternary phosphonium salt and / or phosphine compound used in the present invention, R _{29 to} R _{35 in the} general formula (IX) or (IX) are each a hydrocarbon group having 1 to 22 carbon atoms. Preferably, the hydrocarbon group may have a hydroxyl group, and the CH ₂ group in the hydrocarbon group is substituted by —O—, —O—CO— or —CO—O—. Also good. When the carbon number is 23 or more, the reason is not clear, but the adhesion may be insufficient. Here, a C1-C22 hydrocarbon group is a group which consists only of a carbon atom and a hydrogen atom, and any of a saturated hydrocarbon group and an unsaturated hydrocarbon group may be included, even if it contains a ring structure. Also good. As the hydrocarbon group, for example, methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, cyclohexyl group, octyl group, decyl group, dodecyl group, tetradecyl group, hexadecyl group, octadecyl group, oleyl group, Examples include docosyl group, vinyl group, 2-propynyl group, benzyl group, phenyl group, cinnamyl group, and naphthylmethyl group.

Further, examples of the case where a CH ₂ group in the hydrocarbon group having 1 to 22 carbon atoms is substituted by -O-, as linear, e.g., a methoxymethyl group, ethoxymethyl group, propoxymethyl group , Butoxymethyl group, phenoxymethyl group, methoxyethyl group, ethoxyethyl group, propoxyethyl group, butoxyethyl group, phenoxyethyl group, methoxyethoxymethyl group, methoxyethoxyethyl group, polyethylene glycol group, and polypropylene glycol group An ether group is mentioned. Moreover, as a cyclic thing, ethylene oxide, tetrahydrofuran, oxepane, 1, 3- dioxolane etc. are mentioned, for example.

Examples of the case where the CH ₂ group in the hydrocarbon group having 1 to 22 carbon atoms is substituted by —O—CO— or —CO—O— include, for example, an acetoxymethyl group, an acetoxyethyl group, an acetoxypropyl group Group, acetoxybutyl group, methacryloyloxyethyl group, benzoyloxyethyl group, methoxycarbonyl group, ethoxycarbonyl group and the like.

  Examples of the case where the hydrocarbon group having 1 to 22 carbon atoms has a hydroxyl group include, for example, a hydroxymethyl group, a hydroxyethyl group, a hydroxypropyl group, a hydroxybutyl group, a hydroxypentyl group, a hydroxyhexyl group, and a hydroxycyclohexyl group. , A hydroxyoctyl group, a hydroxydecyl group, a hydroxydodecyl group, a hydroxytetradecyl group, a hydroxyhexadecyl group, a hydroxyoctadecyl group, a hydroxyoleyl group, and a hydroxydocosyl group.

Among them, (B3) the number of carbon atoms of _R 25 _{to R 31} of the quaternary phosphonium salt or phosphine compound is preferably in the range of 1-14. When the carbon number is less than 14, when the quaternary ammonium salt acts as a reaction accelerator, the steric hindrance is moderately small and the reaction promoting effect is enhanced, and the adhesion is further improved.

In the present invention, the carbon number of R _{30 to} R _{32 in} the (B3) quaternary phosphonium salt represented by the general formula (IX) is preferably 2 or more, more preferably 3 or more, Preferably it is 4 or more. When the carbon number is 2 or more, homopolymerization of the epoxy resin due to the quaternary phosphonium salt acting as an initiator is suppressed, and the adhesiveness is further improved.

In the present invention, R ₃₄ and R ₃₅ of the (B3) phosphine compound represented by the general formula (X) are each preferably a hydrocarbon group having 1 to 8 carbon atoms, and the hydrocarbon group is It may have a hydroxyl group, and the CH ₂ group in the hydrocarbon group may be substituted with —O—, —O—CO— or —CO—O—. When the number of carbon atoms is less than 8, the ratio of active sites in the molecule is high, and a large effect of improving adhesion can be obtained even with a small amount.

  In the present invention, the molecular weight of the cation moiety of (B3) quaternary phosphonium salt is preferably within the range of 100 to 400 g / mol, more preferably within the range of 100 to 300 g / mol, and even more preferably 100. Within the range of ~ 200 g / mol. When the molecular weight of the cation moiety is 100 g / mol or more, volatilization is suppressed even during the heat treatment, and a large adhesive improvement effect can be obtained even with a small amount. On the other hand, when the molecular weight of the cation moiety is 400 g / mol or less, the ratio of the active moiety in the molecule is high, and a large adhesion improvement effect can be obtained even with a small amount.

  In the present invention, examples of the cation moiety of the aliphatic quaternary phosphonium salt represented by the general formula (IX) include tetramethylphosphonium, tetraethylphosphonium, tetrapropylphosphonium, tetrabutylphosphonium, methyltriethylphosphonium, methyltriethyl. Propylphosphonium, methyltributylphosphonium, dimethyldiethylphosphonium, dimethyldipropylphosphonium, dimethyldibutylphosphonium, trimethylethylphosphonium, trimethylpropylphosphonium, trimethylbutylphosphonium, (2-methoxyethoxymethyl) triethylphosphonium, (2-acetoxyethyl) trimethylphosphonium Chloride, (2-acetoxyethyl) trimethylphosphonium, (2-hydroxyethyl Trimethylphosphonium, tributyl-n-octylphosphonium, tributyldodecylphosphonium, tributylhexadecylphosphonium, tributyl (1,3-dioxolan-2-ylmethyl) phosphonium, di-t-butyldimethylphosphonium, and trihexyltetradecylphosphonium and bis ( Polyoxyethylene) dimethylphosphonium and the like.

  Examples of the cation moiety of the aromatic quaternary phosphonium salt represented by the general formula (IX) include tetraphenylphosphonium, triphenylmethylphosphonium, diphenyldimethylphosphonium, ethyltriphenylphosphonium, n-butyltriphenylphosphonium, Benzyltriphenylphosphonium, isopropyltriphenylphosphonium, vinyltriphenylphosphonium, allyltriphenylphosphonium, triphenylpropargylphosphonium, t-butyltriphenylphosphonium, heptyltriphenylphosphonium, triphenyltetradecylphosphonium, hexyltriphenylphosphonium, ( Methoxymethyl) triphenylphosphonium, 2-hydroxybenzyltriphenylphosphonium, (4-carboxyl) Butyl) triphenylphosphonium, (3-carboxypropyl) triphenylphosphonium, cinnamyltriphenylphosphonium, cyclopropyltriphenylphosphonium, 2- (1,3-dioxan-2-yl) ethyltriphenylphosphonium, 1- (1 , 3-dioxolan-2-yl) ethyltriphenylphosphonium, (1,3-dioxolan-2-yl) methyltriphenylphosphonium, 4-ethoxybenzyltriphenylphosphonium, ethoxycarbonylmethyl (triphenyl) phosphonium, etc. It is done.

  In the present invention, examples of the anion moiety of the (B3) quaternary phosphonium salt include halogen ions of fluoride anion, chloride anion, bromide anion and iodide anion. Also, for example, hydroxide anion, acetate anion, oxalate anion, hydrogen sulfate anion, benzoate anion, iodate anion, methylsulfonate anion, benzenesulfonate anion, tetraphenylborate ion, tetrafluoroborate ion, hexafluoro Examples include phosphate ions, bis (trifluoromethylsulfonyl) imide ions, and toluenesulfonate anions.

  In the present invention, these quaternary phosphonium salts may be used alone or in combination.

  In the present invention, (B3) quaternary phosphonium salts include, for example, trimethyloctadecylphosphonium chloride, trimethyloctadecylphosphonium bromide, trimethyloctadecylphosphonium hydroxide, trimethyloctadecylphosphonium acetate, trimethyloctadecylphosphonium benzoate, trimethyloctadecylphosphonium-p -Toluenesulfonate, trimethyloctadecylphosphonium hydrochloride, trimethyloctadecylphosphonium tetrachloroiodate, trimethyloctadecylphosphonium hydrogensulfate, trimethyloctadecylphosphonium methylsulfate, benzyltrimethylphosphonium chloride, benzyltrimethylphosphonium bromide, benzyltrimethylphosphonium hydro Sid, benzyltrimethylphosphonium acetate, benzyltrimethylphosphonium benzoate, benzyltrimethylphosphonium-p-toluenesulfonate, tetrabutylphosphonium chloride, tetrabutylphosphonium bromide, tetrabutylphosphonium hydroxide, tetrabutylphosphonium acetate, tetrabutylphosphonium Benzoate, tetrabutylphosphonium-p-toluenesulfonate, (2-methoxyethoxymethyl) triethylphosphonium chloride, (2-methoxyethoxymethyl) triethylphosphonium bromide, (2-methoxyethoxymethyl) triethylphosphonium hydroxide, (2 -Methoxyethoxymethyl) triethylphosphonium-p-toluenesulfonate, (2-acetoxy Til) trimethylphosphonium chloride, (2-acetoxyethyl) trimethylphosphonium bromide, (2-acetoxyethyl) trimethylphosphonium hydroxide, (2-acetoxyethyl) trimethylphosphonium-p-toluenesulfonate, (2-hydroxyethyl) trimethylphosphonium Chloride, (2-hydroxyethyl) trimethylphosphonium bromide, (2-hydroxyethyl) trimethylphosphonium hydroxide, (2-hydroxyethyl) trimethylphosphonium-p-toluenesulfonate, bis (polyoxyethylene) dimethylphosphonium chloride, bis ( Polyoxyethylene) dimethylphosphonium bromide, bis (polyoxyethylene) dimethylphosphonium hydroxide, bis (polyoxyethylene) Len) dimethylphosphonium-p-toluenesulfonate, tetraphenylphosphonium bromide, and tetraphenylphosphonium tetraphenylborate.

  Further, (B3) quaternary phosphonium salts other than the above general formula (IX) include acetonitrile triphenylphosphonium chloride, 1H-benzotriazol-1-yloxytripyrrolidinophosphonium hexafluorophosphate, 1H-benzotriazole-1- Iroxytris (dimethylamino) phosphonium hexafluorophosphate, trans-2-butene-1,4-bis (triphenylphosphonium chloride), (4-carboxybutyl) triphenylphosphonium bromide, (3-carboxypropyl) triphenyl Phosphonium bromide, (2,4-dichlorobenzyl) triphenylphosphonium chloride, 2-dimethylaminoethyltriphenylphosphonium bromide, ethoxycarbonylmethyl (triphenyl) phospho Umbromide, (formylmethyl) triphenylphosphonium chloride, N-methylanilinotriphenylphosphonium iodide, phenacyltriphenylphosphonium bromide, etc. are exemplified, and these quaternary phosphonium salts are also (B3) quaternary phosphonium salts of the present invention. Can be used as

  Examples of the phosphine compound represented by the general formula (X) include triethylphosphine, tripropylphosphine, tributylphosphine, tri-t-butylphosphine, tripentylphosphine, trihexylphosphine, tricyclopentylphosphine, and tricyclohexylphosphine. , Trioctylphosphine, triphenylphosphine, tri (2-furyl) phosphine, dimethylpropylphosphine, dimethylbutylphosphine, dimethylpentylphosphine, dimethylhexylphosphine, dimethylcyclohexylphosphine, dimethyloctylphosphine, dimethyldecylphosphine, dimethyldodecylphosphine, dimethyl Tetradecylphosphine, dimethylhexadecylphosphine, dimethyloctadecylphosphite , Dimethyloleylphosphine, dimethyldocosylphosphine, diethylpropylphosphine, diethylbutylphosphine, diethylpentylphosphine, diethylhexylphosphine, diethylcyclohexylphosphine, diethyloctylphosphine, diethyldecylphosphine, diethyldodecylphosphine, diethyltetradecylphosphine, diethylhexadecyl Phosphine, diethyloctadecylphosphine, diethyloleylphosphine, diethyldocosylphosphine, diethylphenylphosphine, ethyldiphenylphosphine, dipropylmethylphosphine, dipropylethylphosphine, dipropylbutylphosphine, dibutylmethylphosphine, dibutylethylphosphine, dibutylpropylphosphine, Dihexy Methylphosphine, dihexylethylphosphine, dihexylpropylphosphine, dihexylbutylphosphine, dicyclohexylmethylphosphine, dicyclohexylethylphosphine, dicyclohexylpropylphosphine, dicyclohexylbutylphosphine, dicyclohexylphenylphosphine, dioctylmethylphosphine, dioctylethylphosphine, dioctylpropylphosphine, didecylmethyl Phosphine, didecylethylphosphine, didecylpropylphosphine, didecylbutylphosphine, didodecylmethylphosphine, didodecylethylphosphine, didodecylpropylphosphine, didodecylbutylphosphine, ditetradecylmethylphosphine, ditetradecylethylphosphine, di Tetradecylpro Pyrphosphine, ditetradecylbutylphosphine, dihexadecylmethylphosphine, dihexadecylethylphosphine, dihexadecylpropylphosphine, dihexadecylbutylphosphine, trimethanolphosphine, triethanolphosphine, tripropanolphosphine, tributanolphosphine, tri Hexanol phosphine, diethyl methanol phosphine, dipropyl methanol phosphine, diisopropyl methanol phosphine, dibutyl methanol phosphine, diisobutyl methanol phosphine, di-t-butyl methanol phosphine, di (2-ethylhexyl) methanol phosphine, dimethyl ethanol phosphine, diethyl ethanol phosphine, di Propylethanolphosphine, diisopropylethane Phosphine, dibutylethanolphosphine, diisobutylethanolphosphine, di-t-butylethanolphosphine, di-t-butylphenylphosphine, di (2-ethylhexyl) ethanolphosphine, dimethylpropanolphosphine, diethylpropanolphosphine, dipropylpropanolphosphine, diisopropylpropanol Phosphine, dibutylpropanolphosphine, diisobutylpropanolphosphine, di-t-butylpropanolphosphine, di (2-ethylhexyl) propanolphosphine, methyldimethanolphosphine, ethyldimethanolphosphine, propyldimethanolphosphine, isopropyldimethanolphosphine, butyldimethanol Phosphine, isobutyl dimethanol Phosphine, t-butyldimethanolphosphine, (2-ethylhexyl) dimethanolphosphine, methyldiethanolphosphine, ethyldiethanolphosphine, propyldiethanolphosphine, isopropyldiethanolphosphine, butyldiethanolphosphine, isobutyldiethanolphosphine, t-butyldiethanolphosphine, (2 -Ethylhexyl) diethanolphosphine, isopropylphenylphosphine, methoxydiphenylphosphine, ethoxydiphenylphosphine, triphenylphosphine, diphenylmethylphosphine, diphenylethylphosphine, diphenylcyclohexylphosphine, diphenylpropylphosphine, diphenylbutylphosphine, diphenyl-t-butylphosphine, di Phenylpentylphosphine, diphenylhexylphosphine, diphenyloctylphosphine, diphenylbenzylphosphine, phenoxydiphenylphosphine, diphenyl-1-pyrenylphosphine, phenyldimethylphosphine, trimethylphosphine, tri-n-octylphosphine, tri-o-tolylphosphine, tri -M-tolylphosphine, tris-2,6-dimethoxyphenylphosphine and the like.

  Further, (B3) phosphine compounds other than the above general formula (X) include phenyl-2-pyridylphosphine, triphenylphosphine oxide, 1,2-bis (diphenylphosphino) ethane, 1,3-bis (diphenylphosphino). ) Propane, 1,4-bis (diphenylphosphino) butane, and the like.

  In the present invention, the compound represented by the general formula (IX) is preferably tetrabutylphosphonium bromide or tetraphenylphosphonium bromide.

  In the present invention, the compound represented by the general formula (X) is preferably tributylphosphine or triphenylphosphine.

  In the present invention, the sizing agent may contain one or more components other than the component (A) and the component (B). For example, polyalkylene oxides such as polyethylene oxide and polypropylene oxide, compounds obtained by adding polyalkylene oxides such as polyethylene oxide and polypropylene oxide to higher alcohols, polyhydric alcohols, alkylphenols, and styrenated phenols, and ethylene oxide and propylene oxide. Nonionic surfactants such as block copolymers are preferably used. Moreover, you may add a polyester resin, an unsaturated polyester compound, etc. suitably in the range which does not affect the effect of this invention.

  In the present invention, the sizing agent can be diluted with a solvent. Examples of such a solvent include water, methanol, ethanol, isopropanol, acetone, methyl ethyl ketone, dimethylformamide, and dimethylacetamide. Among them, handling is easy and advantageous from the viewpoint of safety. Therefore, water is preferably used.

  In this invention, it is preferable that the adhesion amount of a sizing agent is the range of 0.1-10 mass parts with respect to 100 mass parts of carbon fibers, More preferably, it is the range of 0.2-3 mass parts. When the sizing agent is attached in an amount of 0.1 part by mass or more, when carbon fiber is prepreg and weaved, it can withstand friction caused by a metal guide that passes therethrough, and generation of fluff can be suppressed. Excellent quality such as smoothness. On the other hand, if the amount of sizing agent attached is 10 parts by mass or less, a matrix resin such as an epoxy resin is impregnated inside the carbon fiber bundle without being obstructed by the sizing agent film around the carbon fiber bundle, and in the resulting composite material The generation of voids is suppressed, the quality of the composite material is excellent, and at the same time the mechanical properties are excellent.

  In the present invention, the thickness of the sizing agent layer applied to the carbon fiber and dried is preferably in the range of 2 to 20 nm, and the maximum value of the thickness does not exceed twice the minimum value. By such a uniform sizing agent layer, a large effect of improving adhesiveness can be obtained stably, and further, high-order processability is stable.

  In the present invention, examples of the carbon fiber to which the sizing agent is applied include polyacrylonitrile (PAN) -based, rayon-based, and pitch-based carbon fibers. Of these, PAN-based carbon fibers having an excellent balance between strength and elastic modulus are preferably used.

  Next, a method for producing a PAN-based carbon fiber will be described.

  As a spinning method for obtaining a carbon fiber precursor fiber, spinning methods such as wet, dry, and dry-wet can be used. Among these, it is preferable to use a wet or dry wet spinning method from the viewpoint that a high-strength carbon fiber is easily obtained. As the spinning dope, a polyacrylonitrile homopolymer or copolymer solution or suspension can be used.

  The spinning solution is spun, coagulated, washed with water, and drawn into a precursor fiber by passing it through a die, and the resulting precursor fiber is subjected to a flameproofing treatment and carbonization treatment. Get fiber. As conditions for carbonization treatment and graphitization treatment, the maximum heat treatment temperature is preferably 1100 ° C. or higher, more preferably 1400 to 3000 ° C.

  In the present invention, carbon fibers having fineness are preferably used from the viewpoint of obtaining carbon fibers having high strength and elastic modulus. Specifically, the single fiber diameter of the carbon fiber is preferably 7.5 μm or less, more preferably 6 μm or less, and further preferably 5.5 μm or less. There is no particular lower limit for the single fiber diameter, but if it is 4.5 μm or less, single fiber cutting is likely to occur in the process, and the productivity may decrease.

  The obtained carbon fiber is usually subjected to an oxidation treatment to introduce an oxygen-containing functional group in order to improve adhesion with the matrix resin. As the oxidation treatment method, vapor phase oxidation, liquid phase oxidation, and liquid phase electrolytic oxidation are used. From the viewpoint of high productivity and uniform treatment, liquid phase electrolytic oxidation is preferably used.

  In the present invention, examples of the electrolytic solution used in the liquid phase electrolytic oxidation include an acidic electrolytic solution and an alkaline electrolytic solution.

  Examples of the acidic electrolyte include inorganic acids such as sulfuric acid, nitric acid, hydrochloric acid, phosphoric acid, boric acid, and carbonic acid, organic acids such as acetic acid, butyric acid, oxalic acid, acrylic acid, and maleic acid, or ammonium sulfate and ammonium hydrogen sulfate. And the like. Of these, sulfuric acid and nitric acid exhibiting strong acidity are preferably used.

  Specific examples of the alkaline electrolyte include aqueous solutions of hydroxides such as sodium hydroxide, potassium hydroxide, magnesium hydroxide, calcium hydroxide and barium hydroxide, sodium carbonate, potassium carbonate, magnesium carbonate, calcium carbonate, Aqueous solutions of carbonates such as barium carbonate and ammonium carbonate, aqueous solutions of bicarbonates such as sodium bicarbonate, potassium bicarbonate, magnesium bicarbonate, calcium bicarbonate, barium bicarbonate and ammonium bicarbonate, ammonia, tetraalkylammonium hydroxide And an aqueous solution of hydrazine. Among these, from the viewpoint of not containing an alkali metal that causes curing inhibition of the matrix resin, an aqueous solution of ammonium carbonate and ammonium hydrogen carbonate or an aqueous solution of tetraalkylammonium hydroxide exhibiting strong alkalinity is preferably used.

  In the present invention, (A) from the viewpoint that the covalent bond formation between the epoxy compound and the oxygen-containing functional group on the surface of the carbon fiber is promoted, and the adhesiveness is further improved, after the carbon fiber is electrolytically treated with an alkaline electrolyte, Alternatively, it is preferable to apply a sizing agent after electrolytic treatment in an acidic aqueous solution followed by washing with an alkaline aqueous solution. When electrolytic treatment is performed, the excessively oxidized portion on the carbon fiber surface becomes a fragile layer and exists at the interface, which may be the starting point of destruction when made into a composite material. It is considered that formation of a covalent bond is promoted by dissolution and removal with an aqueous solution. In addition, when there is a residue of the acidic electrolyte on the surface of the carbon fiber, protons in the residue are captured by the component (B), and the hydrogen ion of the oxygen-containing functional group on the surface of the carbon fiber by the component (B), which is the role to be originally played. The effect of pulling out may decrease. For this reason, it is preferable to carry out an electrolytic treatment in an acidic aqueous solution and then neutralize and wash the acidic electrolytic solution with an alkaline aqueous solution. For the above reasons, a further improvement in adhesion can be obtained by a combination of carbon fibers subjected to a specific treatment and a sizing agent.

  The concentration of the electrolytic solution used in the present invention is preferably in the range of 0.01 to 5 mol / liter, more preferably in the range of 0.1 to 1 mol / liter. When the concentration of the electrolytic solution is 0.01 mol / liter or more, the electrolytic treatment voltage is lowered, which is advantageous in terms of operating cost. On the other hand, when the concentration of the electrolytic solution is 5 mol / liter or less, it is advantageous from the viewpoint of safety.

  The temperature of the electrolytic solution used in the present invention is preferably in the range of 10 to 100 ° C, more preferably in the range of 10 to 40 ° C. When the temperature of the electrolytic solution is 10 ° C. or higher, the efficiency of the electrolytic treatment is improved, which is advantageous in terms of operating cost. On the other hand, when the temperature of the electrolytic solution is 100 ° C. or lower, it is advantageous from the viewpoint of safety.

  In the present invention, the amount of electricity in the liquid phase electrolytic oxidation is preferably optimized in accordance with the carbonization degree of the carbon fiber, and a larger amount of electricity is required when processing the carbon fiber having a high elastic modulus.

In the present invention, the current density in the liquid phase electrolytic oxidation is preferably in the range of 1.5 to 1000 amperes / m ² per 1 m ² of the surface area of the carbon fiber in the electrolytic treatment solution, more preferably 3 to 500 amperes. / M ² within the range. When the current density is 1.5 amperes / m ² or more, the efficiency of the electrolytic treatment is improved, which is advantageous in terms of operating cost. On the other hand, when the current density is 1000 amperes / m ² or less, it is advantageous from the viewpoint of safety.

  In the present invention, from the viewpoint that (A) the covalent bond formation between the epoxy compound and the oxygen-containing functional group on the carbon fiber surface is promoted, and the adhesion is further improved, the carbon fiber is made alkaline water-soluble after the oxidation treatment. It is preferable to wash. Among these, it is preferable to perform a liquid phase electrolysis treatment with an acidic electrolyte followed by washing with an alkaline aqueous solution.

  In the present invention, the pH of the alkaline aqueous solution used for washing is preferably in the range of 7 to 14, more preferably in the range of 10 to 14. Specific examples of alkaline aqueous solutions include aqueous solutions of hydroxides such as sodium hydroxide, potassium hydroxide, magnesium hydroxide, calcium hydroxide and barium hydroxide, sodium carbonate, potassium carbonate, magnesium carbonate, calcium carbonate, and barium carbonate. And aqueous solutions of carbonates such as ammonium carbonate, aqueous solutions of bicarbonates such as sodium bicarbonate, potassium bicarbonate, magnesium bicarbonate, calcium bicarbonate, barium bicarbonate and ammonium bicarbonate, ammonia, tetraalkylammonium hydroxide and hydrazine An aqueous solution of Among these, from the viewpoint of not containing an alkali metal that causes curing inhibition of the matrix resin, an aqueous solution of ammonium carbonate or ammonium hydrogen carbonate, or an aqueous solution of tetraalkylammonium hydroxide exhibiting strong alkalinity is preferably used.

  In the present invention, as a method for washing carbon fibers with an alkaline aqueous solution, for example, a dipping method and a spray method can be used. Especially, it is preferable to use a dip method from a viewpoint that washing | cleaning is easy, Furthermore, it is a preferable aspect to use a dip method, vibrating a carbon fiber with an ultrasonic wave.

  In the present invention, it is preferable that the carbon fiber is washed with an electrolytic treatment or an alkaline aqueous solution, then washed with water and dried. In this case, if the drying temperature is too high, the functional groups present on the outermost surface of the carbon fiber are likely to disappear due to thermal decomposition. Therefore, it is desirable to dry at the lowest possible temperature. Specifically, the drying temperature is preferably 250 ° C. Hereinafter, drying at 210 ° C. or lower is more preferable.

  Examples of the means for applying (coating) the sizing agent to the carbon fiber include a method of immersing the carbon fiber in a sizing liquid through a roller, a method of contacting the carbon fiber with a roller to which the sizing liquid is attached, and a sizing liquid being atomized. There is a method of spraying on carbon fiber. Further, the sizing agent applying means may be either a batch type or a continuous type, but a continuous type capable of improving productivity and reducing variation is preferably used. At this time, it is preferable to control the sizing solution concentration, temperature, yarn tension, and the like so that the amount of the sizing agent active ingredient attached to the carbon fiber is uniformly attached within an appropriate range. Moreover, it is also a preferable aspect that the carbon fiber is vibrated with ultrasonic waves when the sizing agent is applied.

  In this invention, after apply | coating a sizing agent to carbon fiber, it is necessary to heat-process by microwave irradiation and / or infrared irradiation. In the heat treatment by microwave irradiation and / or infrared irradiation, the carbon fiber surface is heated to a temperature range of 160 to 260 ° C. by microwave irradiation and / or infrared irradiation, and then the carbon fiber surface temperature is set to a temperature range of 160 to 260 ° C. It is necessary to heat-treat for 30 to 600 seconds in a state of being held in the water. The surface temperature of the carbon fiber by microwave irradiation and / or infrared irradiation is preferably set to a temperature range of 170 to 250 ° C, and a temperature range of 180 to 240 ° C is preferable. The heating time in the temperature range is preferably 30 to 500 seconds, more preferably 30 to 300 seconds. When the heat treatment conditions by microwave irradiation and / or infrared irradiation are less than 160 ° C. and / or less than 30 seconds, covalent bond formation between the epoxy resin of the sizing agent and the oxygen-containing functional group on the surface of the carbon fiber is formed. Not promoted, the adhesion between the carbon fiber and the matrix resin becomes insufficient. On the other hand, when the heat treatment condition exceeds 260 ° C. and / or exceeds 600 seconds, volatilization of the tertiary amine compound and / or tertiary amine salt occurs, and the covalent bond formation is not promoted, and the carbon fiber and the matrix resin Adhesiveness with is insufficient.

  The microwave used for the heat treatment of the carbon fiber coated with the sizing agent can be generated by a microwave generator. A microwave having a frequency of 0.3 GHz to 30 GHz is used. Usually, a microwave having a frequency of 2.45 GHz, which is frequently used in Japan, can be suitably used. When carbon fiber is heated by microwave irradiation, the microwave penetrates into the carbon fiber and is absorbed, so that the object to be heated is shorter in time than when heated with hot air drying or a heating roller. Can be heated to a desired temperature. Moreover, since the microwave can also quickly heat the inside of the carbon fiber, the temperature difference between the inside and the outside of the carbon fiber bundle can be reduced, and the adhesion unevenness of the sizing agent can be reduced. .

  When irradiating the carbon fiber surface with microwaves, it is preferable to adjust the output in consideration of the temperature of the carbon fiber surface. When performing batch type microwave irradiation, first irradiate the microwave with high output to bring the carbon fiber to the desired temperature in a short time, then reduce the output and irradiate the microwave to reduce the carbon fiber. Heat treatment is preferably performed while maintaining at a desired temperature for a predetermined time. Irradiation can be performed in any atmosphere in air or inert gas.

  Irradiation to the carbon fiber coated with the sizing agent is performed using a near-infrared heater or a far-infrared heater that emits near-infrared and far-infrared rays having a wavelength of about 0.7 μm to 30 μm. Since the carbon fiber absorbs near infrared rays and far infrared rays having a wavelength of about 0.7 μm to 30 μm, the carbon fibers can be efficiently heated by infrared irradiation. Since the inside of the carbon fiber can be rapidly heated by infrared irradiation, the temperature difference between the inside and outside of the carbon fiber bundle can be reduced, and the uneven adhesion of the sizing agent can be reduced.

  When irradiating infrared rays onto the carbon fiber surface, it is preferable to adjust the output in consideration of the temperature of the carbon fiber surface, as in the case of microwave irradiation. When performing infrared wave irradiation in batch mode, first irradiate infrared rays with high output to bring the carbon fiber to the desired temperature in a short time, then reduce the output and irradiate infrared rays to bring the carbon fiber to the desired temperature. It is preferable to perform the heat treatment while maintaining for a predetermined time. Irradiation can be performed in any atmosphere in air or inert gas.

  In the present invention, the strand strength of the obtained carbon fiber bundle is preferably 3.5 GPa or more, more preferably 4 GPa or more, and further preferably 5 GPa. Moreover, it is preferable that the strand elastic modulus of the obtained carbon fiber bundle is 220 GPa or more, More preferably, it is 240 GPa or more, More preferably, it is 280 GPa or more.

  In the present invention, the strand tensile strength and elastic modulus of the carbon fiber bundle can be determined according to the following procedure in accordance with the resin impregnated strand test method of JIS-R-7608 (2004). As the resin formulation, “Celoxide (registered trademark)” 2021P (manufactured by Daicel Chemical Industries) / 3 boron trifluoride monoethylamine (manufactured by Tokyo Chemical Industry Co., Ltd.) / Acetone = 100/3/4 (part by mass) is used. As curing conditions, normal pressure, 130 ° C., and 30 minutes are used. Ten strands of the carbon fiber bundle were measured, and the average value was defined as the strand tensile strength and the strand elastic modulus.

  In the present invention, the carbon fiber has a surface oxygen concentration (O / C), which is a ratio of the number of atoms of oxygen (O) and carbon (C) on the fiber surface measured by X-ray photoelectron spectroscopy. The thing within the range of 05-0.50 is preferable, More preferably, it is a thing within the range of 0.06-0.30, More preferably, it is a thing within the range of 0.07-0.20. When the surface oxygen concentration (O / C) is 0.05 or more, an oxygen-containing functional group on the surface of the carbon fiber can be secured and strong adhesion with the matrix resin can be obtained. Moreover, when the surface oxygen concentration (O / C) is 0.5 or less, a decrease in strength of the carbon fiber itself due to oxidation can be suppressed.

The surface oxygen concentration of the carbon fiber is determined by X-ray photoelectron spectroscopy according to the following procedure. First, carbon fibers from which dirt and the like adhering to the carbon fiber surface were removed with a solvent were cut into 20 mm, spread and arranged on a copper sample support base, and then AlKα ₁ and ₂ were used as X-ray sources. The chamber is kept at 1 × 10 ⁻⁸ Torr. The kinetic energy value (KE) of the main peak of C _1s is set to 1202 eV as a peak correction value associated with charging during measurement. C _1s peak area, _K.P. E. Is obtained by drawing a straight base line in the range of 1191 to 1205 eV. O _1s peak area, E. Is obtained by drawing a straight base line in the range of 947 to 959 eV.

Here, the surface oxygen concentration is calculated as an atomic ratio by using a sensitivity correction value unique to the apparatus from the ratio of the O _1s peak area to the C _1s peak area. As the X-ray photoelectron spectroscopy apparatus, ESCA-1600 manufactured by ULVAC-PHI Co., Ltd. was used, and the sensitivity correction value unique to the apparatus was 2.33.

  Then, the composite material using the carbon fiber manufactured by the method of this invention is demonstrated. As the matrix resin for the composite material, a thermosetting resin and a thermoplastic resin are used.

  The carbon fiber obtained by the method for producing carbon fiber of the present invention is used in the form of, for example, tow, woven fabric, knitted fabric, braid, web, mat, chopped and the like. In particular, for applications that require high specific strength and high specific modulus, a tow in which carbon fibers are aligned in one direction is most suitable, and a prepreg impregnated with a matrix resin is preferably used.

  Examples of the thermosetting resin include unsaturated polyester resins, vinyl ester resins, epoxy resins, phenol resins, melamine resins, urea resins, cyanate ester resins, and bismaleimide resins. Among them, it is preferable to use an epoxy resin because it has an advantage of excellent balance of mechanical properties and small curing shrinkage. For the purpose of improving toughness and the like, the thermosetting resin can contain a thermoplastic resin described later or an oligomer thereof.

  Examples of the thermoplastic resin include “polyester resins such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polytrimethylene terephthalate (PTT), polyethylene naphthalate (PEN), and liquid crystalline polyester; polyethylene (PE), Polyolefin resins such as polypropylene (PP), polybutylene, acid-modified polyethylene (m-PE), acid-modified polypropylene (m-PP), and acid-modified polybutylene; polyoxymethylene (POM), polyamide (PA), polyphenylene sulfide (PPS) ), Etc .; polyketone (PK), polyetherketone (PEK), polyetheretherketone (PEEK), polyetherketoneketone (PEKK), polyethernitrile (P) N); fluorinated resin such as polytetrafluoroethylene; crystalline resin such as “liquid crystal polymer (LCP)”, styrene resin such as “polystyrene (PS), acrylonitrile styrene (AS), acrylonitrile butadiene styrene (ABS)”, polycarbonate (PC), polymethyl methacrylate (PMMA), polyvinyl chloride (PVC), unmodified or modified polyphenylene ether (PPE), polyimide (PI), polyamideimide (PAI), polyetherimide (PEI), polysulfone ( PSU), polyethersulfone, polyarylate (PAR) "and other amorphous resins; phenolic resins, phenoxy resins, polystyrene elastomers, polyolefin elastomers, polyurethane elastomers, polyesters There are at least one thermoplastic resin selected from a copolymer, a modified body, and the like such as a lastmer, a polyamide-based elastomer, a polybutadiene-based elastomer, a polyisoprene-based elastomer, various thermoplastic elastomers such as a fluorine-based resin and an acrylonitrile-based elastomer. Preferably used.

  Next, the composite material when the matrix resin is a thermosetting resin will be described.

  The prepreg can be prepared by a wet method in which a matrix resin is dissolved in a solvent such as methyl ethyl ketone or methanol to lower the viscosity and impregnated, and a hot melt method (dry method) in which the viscosity is decreased by heating and impregnated. .

  The wet method is a method in which carbon fibers are immersed in a matrix resin solution, and then lifted and the solvent is evaporated using an oven. The hot melt method is a method in which a matrix resin whose viscosity is reduced by heating is directly reinforced fiber. Or a coating film prepared from a matrix resin is once placed on a release paper or the like, and then the carbon fiber is coated with a matrix resin by heating and pressurizing the film from both sides or one side of the carbon fiber. It is a method of impregnating. The hot melt method is a preferable method because substantially no solvent remains in the prepreg.

  After laminating the obtained prepreg, a composite material is produced by a method of heating and curing the matrix resin while applying pressure to the laminate. As a method for applying heat and pressure, a press molding method, an autoclave molding method, a bagging molding method, a wrapping tape method, an internal pressure molding method, a vacuum pressure molding method, and the like are employed. The composite material is formed by directly impregnating the matrix resin with carbon fiber without using a prepreg, followed by heat curing, for example, a hand lay-up method, a resin injection molding method, a resin transfer molding method, etc. It can also be produced by the method. In these methods, it is preferable to prepare a resin by mixing two liquids of a matrix resin main component and a curing agent immediately before use.

  Next, the composite material when the matrix resin is a thermoplastic resin will be described.

  Composite materials using thermoplastic resin as the matrix resin include, for example, injection molding (injection compression molding, gas assist injection molding, insert molding, etc.), blow molding, rotational molding, extrusion molding, press molding, transfer molding, and filament winding molding. However, injection molding is preferably used from the viewpoint of productivity.

  As the form of the molding material used for such molding, pellets, stampable sheets, prepregs and the like can be used, but the most preferable molding material is a pellet used for injection molding. The pellets generally refer to those obtained by kneading a thermoplastic resin and chopped fibers or continuous fibers in an extruder, and extruding and pelletizing. In the above-mentioned pellet, the fiber length in the pellet is shorter than the length in the pellet longitudinal direction, and the pellet includes a long fiber pellet. The long fiber pellets, as described in Japanese Examined Patent Publication No. 63-37694, have fibers arranged substantially parallel to the longitudinal direction of the pellet, and the fiber length in the pellet is equal to or longer than the pellet length. It points to what is. In this case, the thermoplastic resin may be impregnated or coated in the fiber bundle. In particular, in the case of a long fiber pellet coated with a thermoplastic resin, the fiber bundle may be pre-impregnated with a resin having the same viscosity as the coated fiber or a resin having a lower viscosity (or lower molecular weight) than the coated resin. Good.

  In order for the composite material to have excellent electrical conductivity and mechanical properties (particularly strength and impact resistance), it is effective to increase the fiber length in the molded product. Among the pellets, it is preferable to use long fiber pellets.

  Examples of the use of the composite material composed of the carbon fiber and the thermosetting resin and / or the thermoplastic resin obtained by the carbon fiber manufacturing method of the present invention include, for example, a personal computer, a display, an OA device, a mobile phone, a portable information terminal, Facsimile, compact disc, portable MD, portable radio cassette, PDA (personal information terminal such as electronic notebook), video camera, digital still camera, optical equipment, audio, air conditioner, lighting equipment, recreational goods, toy goods, and other home appliances Electrical and electronic equipment casings and internal parts such as trays and chassis and their cases, mechanical parts, construction materials such as panels, motor parts, alternator terminals, alternator connectors, IC regulators, light meter potentiometer bases, suspensions Parts, waste Various valves such as gas valves, fuel related, exhaust or intake pipes, air intake nozzle snorkel, intake manifold, various arms, various frames, various hinges, various bearings, fuel pump, gasoline tank, CNG tank, engine coolant joint , Carburetor main body, carburetor spacer, exhaust gas sensor, cooling water sensor, oil temperature sensor, brake pad wear sensor, throttle position sensor, crankshaft position sensor, air flow meter, brake butt wear sensor, thermostat base for air conditioner, heating temperature Wind flow control valve, brush holder for radiator motor, water pump impeller, turbine vane, wiper motor related parts , Distributor, Starter switch, Starter relay, Transmission wire harness, Window washer nozzle, Air conditioner panel switch board, Fuel related electromagnetic valve coil, Fuse connector, Battery tray, AT bracket, Headlamp support, Pedal housing, Handle , Door beam, protector, chassis, frame, armrest, horn terminal, step motor rotor, lamp socket, lamp reflector, lamp housing, brake piston, noise shield, radiator support, spare tire cover, seat shell, solenoid bobbin, engine oil filter, Ignition case, under cover, scuff plate, pillar trim, propeller shaft, wheel , Fenders, fascias, bumpers, bumper beams, bonnets, aero parts, platforms, cowl louvers, roofs, instrument panels, spoilers and various modules, motorcycle related parts, parts and skins and landing gear pods, winglets Aircraft-related parts such as spoilers, edges, ladders, elevators, failings, and ribs, members and skins, windmill blades, and the like. In particular, it is preferably used for aircraft members, windmill blades, automobile outer plates, casings of electronic devices, trays, chassis, and the like.

  EXAMPLES Next, although an Example demonstrates this invention concretely, this invention is not restrict | limited by these Examples.

<Strand tensile strength and elastic modulus of carbon fiber bundle>
The strand tensile strength and strand elastic modulus of the carbon fiber bundle were determined according to the following procedure in accordance with the resin impregnated strand test method of JIS-R-7608 (2004). As the resin formulation, “Celoxide (registered trademark)” 2021P (manufactured by Daicel Chemical Industries) / 3 boron trifluoride monoethylamine (manufactured by Tokyo Chemical Industry Co., Ltd.) / Acetone = 100/3/4 (part by mass) is used. As curing conditions, normal pressure, temperature of 125 ° C., and time of 30 minutes were used. Ten strands of the carbon fiber bundle were measured, and the average value was defined as the strand tensile strength and the strand elastic modulus.

<Surface oxygen concentration of carbon fiber (O / C)>
The surface oxygen concentration (O / C) of the carbon fiber was determined by X-ray photoelectron spectroscopy according to the following procedure. First, the carbon fiber from which the dirt adhering to the surface with a solvent is removed is cut to about 20 mm and spread on a copper sample support. Next, the sample support is set in the sample chamber, and the inside of the sample chamber is kept at 1 × 10 ⁻⁸ Torr. Subsequently, AlKα ₁ and ₂ were used as an X-ray source, and measurement was performed with a photoelectron escape angle of 90 °. In addition, the kinetic energy value (KE) of the main peak of C _1s was adjusted to 1202 eV as a peak correction value associated with charging during measurement. C _1s peak area, _K.P. E. As a linear base line in the range of 1191 to 1205 eV. In addition, the O _1s peak area is _{expressed as K.I.} E. As a linear base line in the range of 947 to 959 eV. Here, the surface oxygen concentration is calculated as an atomic ratio by using a sensitivity correction value unique to the apparatus from the ratio of the O _1s peak area to the C _1s peak area. As the X-ray photoelectron spectroscopy apparatus, ESCA-1600 manufactured by ULVAC-PHI Co., Ltd. was used, and the sensitivity correction value unique to the apparatus was 2.33.

<Measurement method of sizing adhesion amount>
About 2 g of sizing-attached carbon fiber bundle was weighed (W1) (reading up to the fourth decimal place) and then placed in an electric furnace (capacity 120 cm ³ ) set at a temperature of 450 ° C. in a nitrogen stream of 50 ml / min for 15 minutes. Leave to allow the sizing agent to completely pyrolyze. Then, the carbon fiber bundle is transferred to a container in a dry nitrogen stream of 20 liters / minute and cooled for 15 minutes, and the carbon fiber bundle is weighed (W2) (reads up to the fourth decimal place), and the sizing adhesion amount is obtained by W1-W2. . A value obtained by converting this sizing adhesion amount into an amount with respect to 100 parts by mass of the carbon fiber bundle (rounded off to the third decimal place) was defined as a mass part of the adhering sizing agent. The measurement was performed twice, and the average value was defined as the mass part of the sizing agent.

<Measurement of interfacial shear strength (IFSS)>
Interfacial shear strength (IFSS) is measured by the following procedures (a) to (d).
(A) Preparation of resin 100 parts by mass of a bisphenol A type epoxy resin compound “jER (registered trademark)” 828 (manufactured by Mitsubishi Chemical Corporation) and 14.5 parts by mass of metaphenylenediamine (manufactured by Sigma-Aldrich Japan Co., Ltd.) , Put each in a container. Thereafter, heating is performed at a temperature of 75 ° C. for 15 minutes in order to reduce the viscosity of the jER828 and dissolve the metaphenylenediamine. Then, both are mixed well and vacuum defoaming is performed at a temperature of 80 ° C. for about 15 minutes.

(B) Fixing the carbon fiber single yarn to the special mold Pull out the single fiber from the carbon fiber bundle, and fix both ends with an adhesive in a state where a constant tension is applied to the single fiber in the longitudinal direction of the dumbbell mold. Then, in order to remove the water | moisture content adhering to carbon fiber and a mold, it vacuum-drys for 30 minutes or more at the temperature of 80 degreeC. The dumbbell mold is made of silicone rubber, and the shape of the casting part is a central part width of 5 mm, a length of 25 mm, a both end part width of 10 mm, and an overall length of 150 mm.

(C) From resin casting to curing The resin adjusted in the above procedure (b) is poured into the mold after the vacuum drying in the above step (b), and the temperature rising rate is 1.5 ° C. / The temperature rises to 75 ° C in minutes and is maintained for 2 hours, then the temperature rises to 125 ° C at a temperature rising rate of 1.5 minutes, held for 2 hours, and then lowered to a temperature of 30 ° C at a temperature lowering rate of 2.5 ° C / min. . Then, it demolds and a test piece is obtained.

(D) Measurement of interfacial shear strength (IFSS) A tensile force was applied to the test piece obtained in the above procedure (c) in the fiber axis direction (longitudinal direction) to cause a strain of 12%, and then the test piece was tested with a polarizing microscope. The number of fiber breaks N (pieces) in the range of 22 mm at the center of each piece is measured. Next, the average broken fiber length la is calculated by the formula of la (μm) = 22 × 1000 (μm) / N (pieces). Next, the critical fiber length lc is calculated from the average broken fiber length la by the following formula: lc (μm) = (4/3) × la (μm). The strand tensile strength σ and the diameter d of the carbon fiber single yarn are measured, and the interface shear strength IFSS, which is an index of the bond strength between the carbon fiber and the resin interface, is calculated by the following equation. In the examples, the average of the number of measurements n = 5 was used as the test result.
Interfacial shear strength IFSS (MPa) = σ (MPa) × d (μm) / (2 × lc) (μm)

  The materials and components used in each example and each comparative example are as follows.

-(A1) component: A-1 to A-7
A-1: “jER (registered trademark)” 152 (manufactured by Mitsubishi Chemical Corporation)
Phenol novolac glycidyl ether epoxy equivalent: 175 g / mol, epoxy group number: 3
A-2: “EPICLON (registered trademark)” N660 (manufactured by DIC Corporation)
Cresol novolak glycidyl ether Epoxy equivalent: 206 g / mol, Epoxy group number: 3
A-3: “Araldite (registered trademark)” MY721 (manufactured by Huntsman Advanced Materials)
N, N, N ′, N′-tetraglycidyl-4,4′-diaminodiphenylmethane Epoxy equivalent: 113 g / mol, number of epoxy groups: 4
A-4: “jER (registered trademark)” 828 (manufactured by Mitsubishi Chemical Corporation)
Diglycidyl ether of bisphenol A Epoxy equivalent: 189 g / mol, Number of epoxy groups: 2
A-5: “jER (registered trademark)” 1001 (manufactured by Mitsubishi Chemical Corporation)
Diglycidyl ether of bisphenol A Epoxy equivalent: 475 g / mol, Number of epoxy groups: 2
A-6: “Denacol (registered trademark)” EX-810 (manufactured by Nagase ChemteX Corporation)
Diglycidyl ether of ethylene glycol Epoxy equivalent: 113 g / mol, Number of epoxy groups: 2
A-7: TETRAD-X (Mitsubishi Gas Chemical Co., Ltd.)
Tetraglycidyl metaxylenediamine Epoxy equivalent: 100 g / mol, Number of epoxy groups: 4

・ Applicable to both (A1) component and (A2) component: A-8
A-8: “Denacol (registered trademark)” EX-611 (manufactured by Nagase ChemteX Corporation)
Sorbitol polyglycidyl ether epoxy equivalent: 167 g / mol, number of epoxy groups: 4
Number of hydroxyl groups: 2

-(A2) component: A-9, A-10
A-9: “Denacol (registered trademark)” EX-731 (manufactured by Nagase ChemteX Corporation)
N-glycidyl phthalimide epoxy equivalent: 216 g / mol, number of epoxy groups: 1
Number of imide groups: 1
A-10: “Adeka Resin (registered trademark)” EPU-6 (manufactured by ADEKA Corporation)
Urethane modified epoxy Epoxy equivalent: 250 g / mol, Epoxy group number: 1 or more Urethane group: 1 or more

-(B1) component: B-1 to B-13, B-25 to B-27
B-1: “DBU (registered trademark)” (manufactured by Sun Apro Co., Ltd.) (corresponding to formula (III))
1,8-diazabicyclo [5,4,0] -7-undecene, molecular weight: 152
B-2: Tributylamine (manufactured by Tokyo Chemical Industry Co., Ltd.), molecular weight: 185.4 (corresponding to formula (IV))
B-3: N, N-dimethylbenzylamine (manufactured by Tokyo Chemical Industry Co., Ltd.), molecular weight: 135.21 (corresponding to formula (IV))
B-4: 1,8-bis (dimethylamino) naphthalene (manufactured by Aldrich)
Another name: proton sponge, molecular weight: 214.31 (corresponding to formula (V))
B-5: 2,4,6-tris (dimethylaminomethyl) phenol (manufactured by Tokyo Chemical Industry Co., Ltd.)
Alias: DMP-30, molecular weight: 265.39 (corresponding to formula (VI))
B-6: DBN (manufactured by San Apro Co., Ltd.), molecular weight: 124 (corresponding to formula (III))
1,5-diazabicyclo [4,3,0] -5-nonene B-7: imidazole compound (corresponding to formula (III))
1-benzyl-imidazole (manufactured by Tokyo Chemical Industry Co., Ltd.), molecular weight: 158.2
B-8: U-CAT SA1 (manufactured by San Apro Co., Ltd.) (corresponding to formula (III))
DBU-phenol salt, molecular weight: 246.11
B-9: U-CAT SA102 (manufactured by Sun Apro Co., Ltd.) (corresponding to formula (III))
DBU-octylate: molecular weight: 296.45
B-10: U-CAT SA506 (manufactured by San Apro Co., Ltd.) (corresponding to formula (III))
DBU-p-toluenesulfonate, molecular weight: 324.44
B-11: N-ethylmorpholine (manufactured by Tokyo Chemical Industry Co., Ltd.), molecular weight: 115.17 (corresponding to formula (VIII))
B-12: 2,6-lutidine (manufactured by Tokyo Chemical Industry Co., Ltd.), molecular weight: 107.15 (corresponding to formula (VII))
B-13: 4-pyridinemethanol (manufactured by Tokyo Chemical Industry Co., Ltd.), molecular weight: 109.13 (corresponds to formula (VII))

B-25: Triisopropanolamine (manufactured by Tokyo Chemical Industry Co., Ltd.), molecular weight: 191.27 (corresponding to formula (IV))
B-26: Triethanolamine (manufactured by Tokyo Chemical Industry Co., Ltd.), molecular weight: 149.19 (corresponding to formula (IV))
B-27: N, N-diisopropylethylamine (manufactured by Tokyo Chemical Industry Co., Ltd.), molecular weight: 129.24 (corresponding to formula (IV))

-(B2) component: B-14 to B-20
B-14: Benzyltrimethylammonium bromide (R ₁ has 7 carbon atoms, R _{2 to} R ₄ each have 1 carbon atom, anion site is bromide anion, manufactured by Tokyo Chemical Industry Co., Ltd., corresponds to formula (I))
B-15: Tetrabutylammonium bromide (R _{1 to} R ₄ each have 4 carbon atoms, the anion portion is a bromide anion, manufactured by Tokyo Chemical Industry Co., Ltd., corresponding to formula (I))
B-16: Trimethyloctadecyl ammonium bromide (R ₁ has 18 carbon atoms, R _{2 to} R ₄ each have 1 carbon atom, anion sites are bromide anions, manufactured by Tokyo Chemical Industry Co., Ltd., corresponding to formula (I))
B-17: (2-methoxyethoxymethyl) triethylammonium chloride (R ₁ has 4 carbon atoms, R _{2 to} R ₄ have 2 carbon atoms, anion sites are chloride anions, manufactured by Tokyo Chemical Industry Co., Ltd., Corresponds to formula (I)
B-18: (2-acetoxyethyl) trimethylammonium chloride (R ₁ has 4 carbon atoms, R _{2 to} R ₄ each have 1 carbon atom, anion sites are chloride anions, manufactured by Tokyo Chemical Industry Co., Ltd., formula (Applicable to (I))
B-19: (2-hydroxyethyl) trimethylammonium bromide (R ₁ has 2 carbon atoms, R _{2 to} R ₄ each have 1 carbon atom, anion sites are bromide anion, manufactured by Tokyo Chemical Industry Co., Ltd., formula ( Corresponds to I)
B-20: 1-hexadecylpyridinium chloride (R ₅ has 16 carbon atoms, R ₆ and R ₇ are each a hydrogen atom, anion sites are chloride anions, manufactured by Tokyo Chemical Industry Co., Ltd., formula (II) )

-(B3) component: B-21 to B-24
B-21: Tetrabutylphosphonium bromide (R _{25 to} R ₂₈ each have 4 carbon atoms, the anion portion is bromide anion, manufactured by Tokyo Chemical Industry Co., Ltd., corresponding to formula (IX)) Molecular weight: 339
B-22: Tetraphenylphosphonium bromide (R _{25 to} R ₂₈ each have 6 carbon atoms, the anion portion is a bromide anion, manufactured by Tokyo Chemical Industry Co., Ltd., corresponding to formula (IX)), molecular weight: 419
B-23: Tributylphosphine (R _{29 to} R ₃₁ each have 4 carbon atoms, manufactured by Tokyo Chemical Industry Co., Ltd., corresponding to formula (X)), molecular weight: 202
B-24: Triphenylphosphine (R _{29 to} R ₃₁ each have 6 carbon atoms, manufactured by Tokyo Chemical Industry Co., Ltd., corresponding to formula (X)), molecular weight: 262

-(C) component (other components): C-1 and C-2
C-1: “Denacol (registered trademark)” EX-141 (manufactured by Nagase ChemteX Corporation)
Phenyl glycidyl ether epoxy equivalent: 151 g / mol, number of epoxy groups: 1
C-2: Hexamethylenediamine (manufactured by Tokyo Chemical Industry Co., Ltd.), molecular weight: 116

Example 1
The present example includes the following first step and second step.
-Step I: Process for producing carbon fiber as raw material A copolymer composed of 99 mol% of allylonitrile and 1 mol% of itaconic acid is spun and fired, the total number of filaments is 24,000, and the total fineness is 1. Carbon fiber having 1,000 tex, specific gravity of 1.8, strand tensile strength of 6.2 GPa and strand tensile modulus of 300 GPa was obtained. Subsequently, the carbon fiber was subjected to an electrolytic surface treatment with an aqueous solution of ammonium hydrogen carbonate having a concentration of 0.1 mol / l as an electrolytic solution at an electric charge of 50 coulomb per gram of carbon fiber. The carbon fiber subjected to the electrolytic surface treatment was subsequently washed with water and dried in heated air at a temperature of 150 ° C. to obtain a carbon fiber as a raw material. At this time, the surface oxygen concentration O / C was 0.16. This was designated as carbon fiber A.

Step II: Step of adhering sizing agent to carbon fiber (A-1) and (B-1) were mixed at a mass ratio of 100: 3, and acetone was further mixed to dissolve the sizing agent uniformly. A 1% by weight acetone solution was obtained. The acetone solution of this sizing agent was applied to the surface-treated carbon fiber A by an immersion method, and then a microwave irradiation device (manufactured by Micro Electronics Co., Ltd., 2.45 GHz microwave heating device “MMG-213VP” )) Was used to irradiate microwaves, and the temperature outside the carbon fiber bundle was measured with an infrared thermotracer, and the output was adjusted to 200 ° C. for 10 seconds, followed by heating. Subsequently, it was kept at 200 ° C. for 30 seconds to obtain a sizing agent-coated carbon fiber bundle. The adhesion amount of the sizing agent was adjusted to 1 part by mass with respect to 100 parts by mass of the surface-treated carbon fiber. Subsequently, using the obtained sizing agent-coated carbon fibers, one carbon fiber on each of the outside and inside of the carbon fiber bundle was extracted, and the interfacial shear strength (IFSS) was measured. The results are summarized in Table 1. As a result, it was found that the outer IFSS of the carbon fiber bundle was 40 MPa and the inner IFSS was 39 MPa, and the adhesion between the outer and inner sides was sufficiently high. It was also found that the difference between the outside and the inside was small and the adhesiveness was uniform.

(Examples 2 to 4)
-Step I: Step of producing carbon fiber as a raw material The same as in Example 1.
-Step II: Step of attaching sizing agent to carbon fiber Same as Example 1 except that in Step II of Example 1, the holding time at 200 ° C is changed from 30 seconds to 15 to 600 seconds. The sizing agent-coated carbon fiber was obtained by the method described above. The adhesion amount of the sizing agent was 1 part by mass with respect to 100 parts by mass of the surface-treated carbon fiber. Using the obtained sizing agent-coated carbon fibers, one carbon fiber on each of the outside and inside of the carbon fiber bundle was extracted, and the interfacial shear strength (IFSS) was measured. The results are summarized in Table 1. As a result, the outer IFSS of the carbon fiber bundle was 35, 41, and 35 MPa, and the inner IFSS was 34, 40, and 35 MPa, indicating that the adhesion between the outer and inner sides was sufficiently high. It was also found that the difference between the outside and the inside was small and the adhesiveness was uniform.

(Example 5)
-Step I: Step of producing carbon fiber as a raw material The same as in Example 1.
Step II: Step of adhering sizing agent to carbon fiber (A-1) and (B-1) were mixed at a mass ratio of 100: 3, and acetone was further mixed to dissolve the sizing agent uniformly. A 1% by weight acetone solution was obtained. Using an acetone solution of this sizing agent, after applying the sizing agent to the surface-treated carbon fiber A by an immersion method, far infrared rays were irradiated using a far infrared heating furnace (manufactured by Yamato Scientific Co., Ltd., DIR631), The temperature outside the carbon fiber bundle was measured with an infrared thermotracer, and the output was adjusted so that the temperature became 200 ° C. in 10 seconds. Subsequently, it was kept at 200 ° C. for 30 seconds to obtain a sizing agent-coated carbon fiber bundle. The adhesion amount of the sizing agent was adjusted to 1 part by mass with respect to 100 parts by mass of the surface-treated carbon fiber. Subsequently, using the obtained sizing agent-coated carbon fibers, one carbon fiber on each of the outside and inside of the carbon fiber bundle was extracted, and the interfacial shear strength (IFSS) was measured. The results are summarized in Table 1. As a result, the outside IFSS of the carbon fiber bundle was 41 MPa, and the inside IFSS was 39 MPa, and it was found that the adhesion between the outside and inside was sufficiently high. It was also found that the difference between the outside and the inside was small and the adhesiveness was uniform.

(Examples 6 to 8)
-Step I: Step of producing carbon fiber as a raw material The same as in Example 1.
-Step II: Step of attaching sizing agent to carbon fiber Same as Example 5 except that in Step II of Example 5, the time maintained at 200 ° C is changed from 30 seconds to 15 to 600 seconds. The sizing agent-coated carbon fiber was obtained by the method described above. The adhesion amount of the sizing agent was 1 part by mass with respect to 100 parts by mass of the surface-treated carbon fiber. Using the obtained sizing agent-coated carbon fibers, one carbon fiber on each of the outside and inside of the carbon fiber bundle was extracted, and the interfacial shear strength (IFSS) was measured. The results are summarized in Table 1. As a result, the IFSS on the outside of the carbon fiber bundle was 37, 42, and 36 MPa, and the IFSS on the inside was 36, 41, and 35 MPa, indicating that the adhesion between the outside and inside was sufficiently high. It was also found that the difference between the outside and the inside was small and the adhesiveness was uniform.

(Comparative Example 1)
-Step I: Step of producing carbon fiber as a raw material The same as in Example 1.
Step II: Step of attaching sizing agent to carbon fiber Sizing agent-coated carbon in the same manner as in Example 1 except that only (A-1) was used in Step II of Example 1. Fiber was obtained. The adhesion amount of the sizing agent was 1 part by mass with respect to 100 parts by mass of the surface-treated carbon fiber. Using the obtained sizing agent-coated carbon fibers, one carbon fiber on each of the outside and inside of the carbon fiber bundle was extracted, and the interfacial shear strength (IFSS) was measured. The results are summarized in Table 1. As a result, the outer IFSS of the carbon fiber bundle was 25 MPa, and the inner IFSS was 23 MPa, indicating that the outer and inner adhesiveness was insufficient.

(Comparative Example 2)
-Step I: Step of producing carbon fiber as a raw material The same as in Example 1.
-Step II: Step of attaching sizing agent to carbon fiber Sizing agent-coated carbon in the same manner as in Example 5 except that only (A-1) was used in Step II of Example 5. Fiber was obtained. The adhesion amount of the sizing agent was 1 part by mass with respect to 100 parts by mass of the surface-treated carbon fiber. Using the obtained sizing agent-coated carbon fibers, one carbon fiber on each of the outside and inside of the carbon fiber bundle was extracted, and the interfacial shear strength (IFSS) was measured. The results are summarized in Table 1. As a result, the outer IFSS of the carbon fiber bundle was 24 MPa, and the inner IFSS was 24 MPa, indicating that the outer and inner adhesiveness was insufficient.

(Comparative Example 3)
-Step I: Step of producing carbon fiber as a raw material The same as in Example 1.
Step II: Step of adhering sizing agent to carbon fiber (A-1) and (B-1) were mixed at a mass ratio of 100: 3, and acetone was further mixed to dissolve the sizing agent uniformly. A 1% by weight acetone solution was obtained. Using this acetone solution of the sizing agent, the sizing agent was applied to the surface-treated carbon fiber A by a dipping method, and then allowed to stand in a temperature-controlled room (held at 25 ° C.) for 24 hours to air dry. Obtained. The adhesion amount of the sizing agent was adjusted to 1 part by mass with respect to 100 parts by mass of the surface-treated carbon fiber. Subsequently, using the obtained sizing agent-coated carbon fibers, one carbon fiber on each of the outside and inside of the carbon fiber bundle was extracted, and the interfacial shear strength (IFSS) was measured. The results are summarized in Table 1. As a result, the outer IFSS of the carbon fiber bundle was 23 MPa and the inner IFSS was 23 MPa, indicating that the outer and inner adhesiveness was insufficient.

(Comparative Example 4)
-Step I: Step of producing carbon fiber as a raw material The same as in Example 1.
Step II: Step of adhering sizing agent to carbon fiber (A-1) and (B-1) were mixed at a mass ratio of 100: 3, and acetone was further mixed to dissolve the sizing agent uniformly. A 1% by weight acetone solution was obtained. Using this acetone solution of the sizing agent, the sizing agent was applied to the surface-treated carbon fiber A by a dipping method, and then carbonized using a hot-air circulating dryer (Isuzu Seisakusho, SS-K-300). Heating was performed by adjusting the output so that the temperature outside the fiber bundle was 200 ° C. in 10 seconds as measured by an infrared thermotracer. However, it was found that the hot air oven did not reach 200 ° C. in 10 seconds.

(Comparative Example 5)
-Step I: Step of producing carbon fiber as a raw material The same as in Example 1.
Step II: Step of adhering sizing agent to carbon fiber (A-1) and (B-1) were mixed at a mass ratio of 100: 3, and acetone was further mixed to dissolve the sizing agent uniformly. A 1% by weight acetone solution was obtained. Using this acetone solution of the sizing agent, the sizing agent was applied to the surface-treated carbon fiber A by a dipping method, and then carbonized using a hot-air circulating dryer (Isuzu Seisakusho, SS-K-300). The temperature outside the fiber bundle was measured with an infrared thermotracer, and the output was adjusted so that the temperature reached 200 ° C. in 30 seconds. Subsequently, it was kept at 200 ° C. for 30 seconds to obtain a sizing agent-coated carbon fiber bundle. The adhesion amount of the sizing agent was adjusted to 1 part by mass with respect to 100 parts by mass of the surface-treated carbon fiber. Subsequently, using the obtained sizing agent-coated carbon fibers, one carbon fiber on each of the outside and inside of the carbon fiber bundle was extracted, and the interfacial shear strength (IFSS) was measured. The results are summarized in Table 1. As a result, it was found that the outer IFSS of the carbon fiber bundle was 38 MPa and the inner IFSS was 33 MPa, and the outer adhesiveness was sufficiently high. Moreover, it turned out that the difference of an outer side and an inner side is large, and adhesiveness is non-uniform | heterogenous.

(Comparative Example 6)
-Step I: Step of producing carbon fiber as a raw material The same as in Example 1.
Step II: Step of adhering sizing agent to carbon fiber (A-1) and (B-1) were mixed at a mass ratio of 100: 3, and acetone was further mixed to dissolve the sizing agent uniformly. A 1% by weight acetone solution was obtained. Using this acetone solution of the sizing agent, the sizing agent was applied to the surface-treated carbon fiber A by a dipping method, and then one side of the carbon fiber bundle was brought into contact with a roller heated to 200 ° C. and held for 60 seconds. An agent-coated carbon fiber bundle was obtained. The adhesion amount of the sizing agent was adjusted to 1 part by mass with respect to 100 parts by mass of the surface-treated carbon fiber. Subsequently, using the obtained sizing agent-coated carbon fiber, one carbon fiber was extracted from each of the outside (side in contact with the roller) and inside of the carbon fiber bundle, and the interfacial shear strength (IFSS) was measured. The results are summarized in Table 1. As a result, it was found that the outer IFSS of the carbon fiber bundle was 37 MPa and the inner IFSS was 31 MPa, and the outer adhesiveness was sufficiently high. Moreover, it turned out that the difference of an outer side and an inner side is large, and adhesiveness is non-uniform | heterogenous.

(Examples 9 to 12)
-Step I: Step of producing carbon fiber as a raw material The same as in Example 1.
-Step II: Step of attaching sizing agent to carbon fiber In Step II of Example 3, the mass ratio of (A-1) and (B-1) was changed to 100: 1 to 100: 20. Except for this, a sizing agent-coated carbon fiber was obtained in the same manner as in Example 3. The adhesion amount of the sizing agent was 1 part by mass with respect to 100 parts by mass of the surface-treated carbon fiber. Using the obtained sizing agent-coated carbon fibers, one carbon fiber on each of the outside and inside of the carbon fiber bundle was extracted, and the interfacial shear strength (IFSS) was measured. The results are summarized in Table 2. As a result, the IFSS on the outside of the carbon fiber bundle was 40, 41, 38, and 37 MPa, and the IFSS on the inside was 40, 40, 38, and 36 MPa, indicating that the adhesion between the outside and inside was sufficiently high. It was also found that the difference between the outside and the inside was small and the adhesiveness was uniform.

(Examples 13 to 16)
-Step I: Step of producing carbon fiber as raw material The same as in Example 5.
-Step II: Step of attaching sizing agent to carbon fiber In Step II of Example 7, the mass ratio of (A-1) and (B-1) was changed to 100: 1 to 100: 20. Except for this, a sizing agent-coated carbon fiber was obtained in the same manner as in Example 7. The adhesion amount of the sizing agent was 1 part by mass with respect to 100 parts by mass of the surface-treated carbon fiber. Using the obtained sizing agent-coated carbon fibers, one carbon fiber on each of the outside and inside of the carbon fiber bundle was extracted, and the interfacial shear strength (IFSS) was measured. The results are summarized in Table 2. As a result, the IFSS on the outside of the carbon fiber bundle was 41, 42, 39, 36 MPa, and the IFSS on the inside was 40, 40, 39, 36 MPa, indicating that the adhesion between the outside and inside was sufficiently high. It was also found that the difference between the outside and the inside was small and the adhesiveness was uniform.

(Comparative Example 7)
-Step I: Step of producing carbon fiber as a raw material The same as in Example 1.
-Step II: Step of attaching sizing agent to carbon fiber In Step II of Example 3, except that the mass ratio of (A-1) and (B-1) was changed to 100: 30, Sizing agent-coated carbon fibers were obtained in the same manner as in Example 3. The adhesion amount of the sizing agent was 1 part by mass with respect to 100 parts by mass of the surface-treated carbon fiber. Using the obtained sizing agent-coated carbon fibers, one carbon fiber on each of the outside and inside of the carbon fiber bundle was extracted, and the interfacial shear strength (IFSS) was measured. The results are summarized in Table 2. As a result, the outer IFSS of the carbon fiber bundle was 25 MPa, and the inner IFSS was 23 MPa, indicating that the outer and inner adhesiveness was insufficient.

(Comparative Example 8)
-Step I: Step of producing carbon fiber as raw material The same as in Example 5.
-Step II: Step of attaching sizing agent to carbon fiber In Step II of Example 7, except that the mass ratio of (A-1) and (B-1) was changed to 100: 30, Sizing agent-coated carbon fibers were obtained in the same manner as in Example 7. The adhesion amount of the sizing agent was 1 part by mass with respect to 100 parts by mass of the surface-treated carbon fiber. Using the obtained sizing agent-coated carbon fibers, one carbon fiber on each of the outside and inside of the carbon fiber bundle was extracted, and the interfacial shear strength (IFSS) was measured. The results are summarized in Table 2. As a result, the outer IFSS of the carbon fiber bundle was 24 MPa, and the inner IFSS was 24 MPa, indicating that the outer and inner adhesiveness was insufficient.

(Examples 17 to 26)
-Step I: Step of producing carbon fiber as a raw material The same as in Example 1.
-Step II: Step of attaching sizing agent to carbon fiber In Step II of Example 7, (A-1) to (A-5), (B-3), (B-14), ( A sizing agent-coated carbon fiber was obtained in the same manner as in Example 7 except for changing to B-21). The adhesion amount of the sizing agent was 1 part by mass with respect to 100 parts by mass of the surface-treated carbon fiber. Using the obtained sizing agent-coated carbon fibers, one carbon fiber on each of the outside and inside of the carbon fiber bundle was extracted, and the interfacial shear strength (IFSS) was measured. The results are summarized in Table 3-1. As a result, the outer IFSS of the carbon fiber bundle was 32 to 41 MPa, and the inner IFSS was 32 to 41 MPa, indicating that the outer and inner adhesiveness was sufficiently high. It was also found that the difference between the outside and the inside was small and the adhesiveness was uniform.

(Examples 27 to 31)
-Step I: Step of producing carbon fiber as a raw material The same as in Example 1.
-Step II: Step of attaching sizing agent to carbon fiber In Step II of Example 7, (A-5) to (A-7), (B-1), (B-3), ( A sizing agent-coated carbon fiber was obtained in the same manner as in Example 7 except for changing to B-21). The adhesion amount of the sizing agent was 1 part by mass with respect to 100 parts by mass of the surface-treated carbon fiber. Using the obtained sizing agent-coated carbon fibers, one carbon fiber on each of the outside and inside of the carbon fiber bundle was extracted, and the interfacial shear strength (IFSS) was measured. The results are summarized in Table 3-2. As a result, the outer IFSS of the carbon fiber bundle was 33 to 40 MPa, and the inner IFSS was 33 to 40 MPa, indicating that the adhesion between the outer and inner sides was sufficiently high. It was also found that the difference between the outside and the inside was small and the adhesiveness was uniform.

(Examples 32-34)
-Step I: Step of producing carbon fiber as a raw material The same as in Example 1.
-Step II: Step of attaching sizing agent to carbon fiber In the step II of Example 3, except for changing to (A-8) to (A-10), the same method as in Example 3 A sizing agent-coated carbon fiber was obtained. The adhesion amount of the sizing agent was 1 part by mass with respect to 100 parts by mass of the surface-treated carbon fiber. Using the obtained sizing agent-coated carbon fibers, one carbon fiber on each of the outside and inside of the carbon fiber bundle was extracted, and the interfacial shear strength (IFSS) was measured. The results are summarized in Table 3-2. As a result, the outer IFSS of the carbon fiber bundle was 34, 33, 33 MPa, and the inner IFSS was 33, 32, 32 MPa, indicating that the adhesion between the outer and inner sides was sufficiently high. It was also found that the difference between the outside and the inside was small and the adhesiveness was uniform.

(Comparative Example 9)
-Step I: Step of producing carbon fiber as a raw material The same as in Example 1.
-Step II: Step of attaching sizing agent to carbon fiber In Step II of Example 7, (A-1) is changed to (C-1), and (B-1) is changed to (B-3). A carbon fiber coated with a sizing agent was obtained in the same manner as in Example 7 except that. The adhesion amount of the sizing agent was 1 part by mass with respect to 100 parts by mass of the surface-treated carbon fiber. Using the obtained sizing agent-coated carbon fibers, one carbon fiber on each of the outside and inside of the carbon fiber bundle was extracted, and the interfacial shear strength (IFSS) was measured. The results are summarized in Table 3-3. As a result, it was found that the outer IFSS of the carbon fiber bundle was 28 MPa and the inner IFSS was 28 MPa, and the adhesion between the outer and inner sides was insufficient.

(Comparative Examples 10, 11, 13, 14)
-Step I: Step of producing carbon fiber as a raw material The same as in Example 1.
-Step II: Step of attaching sizing agent to carbon fiber Only (C-1), (A-2), (A-4) and (A-6) are dissolved in acetone, and the sizing agent is uniformly dissolved. An approximately 1% by mass acetone solution was obtained. Using an acetone solution of this sizing agent, the sizing agent was applied to the surface-treated carbon fiber by a dipping method, and then irradiated with far infrared rays using a far infrared heating furnace (manufactured by Yamato Scientific Co., Ltd., DIR631). Heating was performed by adjusting the output so that the temperature outside the fiber bundle was 200 ° C. in 10 seconds as measured by an infrared thermotracer. Subsequently, it was kept at 200 ° C. for 60 seconds to obtain a sizing agent-coated carbon fiber bundle. The adhesion amount of the sizing agent was adjusted to 1 part by mass with respect to 100 parts by mass of the surface-treated carbon fiber. Subsequently, using the obtained sizing agent-coated carbon fibers, one carbon fiber on each of the outside and inside of the carbon fiber bundle was extracted, and the interfacial shear strength (IFSS) was measured. The results are summarized in Table 3-3. As a result, the outer IFSS of the carbon fiber bundle was 25 to 29 MPa, and the inner IFSS was 24 to 29 MPa, indicating that the outer and inner adhesiveness was insufficient.

(Comparative Examples 12, 15-17)
-Step I: Step of producing carbon fiber as a raw material The same as in Example 1.
-Step II: Steps (A-2), (A-8), (A-9), and (A-10) for attaching the sizing agent to carbon fiber are dissolved in acetone, and the sizing agent is uniformly dissolved. An approximately 1% by mass acetone solution was obtained. After applying the acetone solution of this sizing agent to the surface-treated carbon fiber by the dipping method, a microwave irradiation device (manufactured by Micro Electronics Co., Ltd., 2.45 GHz microwave heating device “MMG-213VP”) ) Was used to irradiate the microwave, and the temperature outside the carbon fiber bundle was measured with an infrared thermotracer, and the output was adjusted to 200 ° C. in 10 seconds, followed by heating. Subsequently, it was kept at 200 ° C. for 60 seconds to obtain a sizing agent-coated carbon fiber bundle. The adhesion amount of the sizing agent was adjusted to 1 part by mass with respect to 100 parts by mass of the surface-treated carbon fiber. Subsequently, using the obtained sizing agent-coated carbon fibers, one carbon fiber on each of the outside and inside of the carbon fiber bundle was extracted, and the interfacial shear strength (IFSS) was measured. The results are summarized in Table 3-3. As a result, the outer IFSS of the carbon fiber bundle was 24-28 MPa and the inner IFSS was 24-28 MPa, indicating that the outer and inner adhesiveness was insufficient.

(Examples 35-39)
-Step I: Step of producing carbon fiber as a raw material The same as in Example 1.
-Step II: Step of attaching sizing agent to carbon fiber In Step II of Example 19, (B-3) is changed to (B-2), (B-4) to (B-7). A carbon fiber coated with a sizing agent was obtained in the same manner as in Example 19 except that. The adhesion amount of the sizing agent was 1 part by mass with respect to 100 parts by mass of the surface-treated carbon fiber. Using the obtained sizing agent-coated carbon fibers, one carbon fiber on each of the outside and inside of the carbon fiber bundle was extracted, and the interfacial shear strength (IFSS) was measured. The results are summarized in Table 4. As a result, the outer IFSS of the carbon fiber bundle was 32 to 45 MPa, and the inner IFSS was 31 to 45 MPa, indicating that the outer and inner adhesiveness was sufficiently high. It was also found that the difference between the outside and the inside was small and the adhesiveness was uniform.

(Example 40)
-Step I: Step of producing carbon fiber as raw material Implemented except that sulfuric acid aqueous solution having a concentration of 0.05 mol / l was used as the electrolytic solution and the amount of electricity was subjected to electrolytic surface treatment at 10 coulomb per gram of carbon fiber. Same as Example 1. At this time, the surface oxygen concentration O / C was 0.16. This was designated as carbon fiber B.
-Step II: Step of attaching sizing agent to carbon fiber Sizing agent-coated carbon fiber was obtained in the same manner as in Example 7. The adhesion amount of the sizing agent was 1 part by mass with respect to 100 parts by mass of the surface-treated carbon fiber. Using the obtained sizing agent-coated carbon fibers, one carbon fiber on each of the outside and inside of the carbon fiber bundle was extracted, and the interfacial shear strength (IFSS) was measured. The results are summarized in Table 4. As a result, the outer IFSS of the carbon fiber bundle was 39 MPa and the inner IFSS was 37 MPa, and it was found that the adhesion between the outer and inner sides was sufficiently high. It was also found that the difference between the outside and the inside was small and the adhesiveness was uniform.

(Example 41)
-Step I: Step of producing carbon fiber as raw material The same procedure as in Example 40 was performed.
Step II: Step of attaching sizing agent to carbon fiber Sizing agent-coated carbon fiber was obtained in the same manner as in Example 23. The adhesion amount of the sizing agent was 1 part by mass with respect to 100 parts by mass of the surface-treated carbon fiber. Using the obtained sizing agent-coated carbon fibers, one carbon fiber on each of the outside and inside of the carbon fiber bundle was extracted, and the interfacial shear strength (IFSS) was measured. The results are summarized in Table 4. As a result, the outside IFSS of the carbon fiber bundle was 32 MPa, and the inside IFSS was 31 MPa, and it was found that the adhesion between the outside and inside was sufficiently high. It was also found that the difference between the outside and the inside was small and the adhesiveness was uniform.

(Example 42)
-Step I: Step of producing carbon fiber as a raw material The carbon fiber B obtained in Example 40 was immersed in an aqueous tetraethylammonium hydroxide solution (pH = 14) and pulled up while being vibrated with ultrasonic waves. At this time, the surface oxygen concentration O / C was 0.15. This was designated as carbon fiber C.
-Step II: Step of attaching sizing agent to carbon fiber Sizing agent-coated carbon fiber was obtained in the same manner as in Example 7. The adhesion amount of the sizing agent was 1 part by mass with respect to 100 parts by mass of the surface-treated carbon fiber. Using the obtained sizing agent-coated carbon fibers, one carbon fiber on each of the outside and inside of the carbon fiber bundle was extracted, and the interfacial shear strength (IFSS) was measured. The results are summarized in Table 4. As a result, it was found that the outer IFSS of the carbon fiber bundle was 42 MPa and the inner IFSS was 41 MPa, and the adhesion between the outer and inner sides was sufficiently high. It was also found that the difference between the outside and the inside was small and the adhesiveness was uniform.

(Examples 43 to 45, 49 to 51)
-Step I: Step of producing carbon fiber as a raw material The same as in Example 1.
-Step II: Step of attaching sizing agent to carbon fiber In Step II of Example 19, (B-3) is changed from (B-8) to (B-10), (B-25) to (B). A sizing agent-coated carbon fiber was obtained in the same manner as in Example 19 except for changing to B-27). The adhesion amount of the sizing agent was 1 part by mass with respect to 100 parts by mass of the surface-treated carbon fiber. Using the obtained sizing agent-coated carbon fibers, one carbon fiber on each of the outside and inside of the carbon fiber bundle was extracted, and the interfacial shear strength (IFSS) was measured. The results are summarized in Table 5-1. As a result, the outer IFSS of the carbon fiber bundle was 35 to 45 MPa, and the inner IFSS was 35 to 45 MPa, indicating that the outer and inner adhesiveness was sufficiently high. It was also found that the difference between the outside and the inside was small and the adhesiveness was uniform.

(Examples 46 to 48)
-Step I: Step of producing carbon fiber as a raw material The same as in Example 1.
-Step II: Step of attaching sizing agent to carbon fiber (A-2) and (B-11), (A-2) and (B-12), (A-2) and (B-13) Were mixed at a mass ratio of 100: 3, and further acetone was mixed to obtain an acetone solution of about 1% by mass in which the sizing agent was uniformly dissolved. After applying the acetone solution of this sizing agent to the surface-treated carbon fiber by the dipping method, a microwave irradiation device (manufactured by Micro Electronics Co., Ltd., 2.45 GHz microwave heating device “MMG-213VP”) ) Was used to irradiate the microwave, and the temperature outside the carbon fiber bundle was measured with an infrared thermotracer, and the output was adjusted to 200 ° C. in 10 seconds, followed by heating. Subsequently, it was kept at 200 ° C. for 60 seconds to obtain a sizing agent-coated carbon fiber bundle. The adhesion amount of the sizing agent was adjusted to 1 part by mass with respect to 100 parts by mass of the surface-treated carbon fiber. Subsequently, using the obtained sizing agent-coated carbon fibers, one carbon fiber on each of the outside and inside of the carbon fiber bundle was extracted, and the interfacial shear strength (IFSS) was measured. The results are summarized in Table 5-1. As a result, the IFSS on the outside of the carbon fiber bundle was 41, 39, 39 MPa, and the IFSS on the inside was 41, 39, 39 MPa, indicating that the adhesion between the outside and inside was sufficiently high. It was also found that the difference between the outside and the inside was small and the adhesiveness was uniform.

(Examples 52 to 58)
-Step I: Step of producing carbon fiber as a raw material The same as in Example 1.
-Step II: Step of attaching sizing agent to carbon fiber Example of Example 7 except that (B-1) is changed to (B-14) to (B-20) in Step II of Example 7. Sizing agent-coated carbon fibers were obtained in the same manner as in No.7. The adhesion amount of the sizing agent was 1 part by mass with respect to 100 parts by mass of the surface-treated carbon fiber. Using the obtained sizing agent-coated carbon fibers, one carbon fiber on each of the outside and inside of the carbon fiber bundle was extracted, and the interfacial shear strength (IFSS) was measured. The results are summarized in Table 5-2. As a result, it was found that the outer IFSS of the carbon fiber bundle was 35 to 42 MPa and the inner IFSS was 34 to 41 MPa, and the adhesion between the outer and inner sides was sufficiently high. It was also found that the difference between the outside and the inside was small and the adhesiveness was uniform.

(Examples 59-61)
-Step I: Step of producing carbon fiber as a raw material The same as in Example 1.
-Step II: Step of attaching sizing agent to carbon fiber Example 2 except that (B-1) is changed to (B-22) to (B-24) in Step II of Example 3. Sizing agent-coated carbon fibers were obtained in the same manner as in No. 3. The adhesion amount of the sizing agent was 1 part by mass with respect to 100 parts by mass of the surface-treated carbon fiber. Using the obtained sizing agent-coated carbon fibers, one carbon fiber on each of the outside and inside of the carbon fiber bundle was extracted, and the interfacial shear strength (IFSS) was measured. The results are summarized in Table 5-2. As a result, the outer IFSS of the carbon fiber bundle was 35, 35, 33 MPa, and the inner IFSS was 35, 35, 32 MPa, and it was found that the adhesion between the outer and inner sides was sufficiently high. It was also found that the difference between the outside and the inside was small and the adhesiveness was uniform.

(Comparative Example 18)
-Step I: Step of producing carbon fiber as a raw material The same as in Example 1.
Step II: Step of attaching sizing agent to carbon fiber Only (A-3) was dissolved in acetone to obtain an acetone solution of about 1% by mass in which the sizing agent was uniformly dissolved. Using an acetone solution of this sizing agent, the sizing agent was applied to the surface-treated carbon fiber by a dipping method, and then irradiated with far infrared rays using a far infrared heating furnace (manufactured by Yamato Scientific Co., Ltd., DIR631). Heating was performed by adjusting the output so that the temperature outside the fiber bundle was 200 ° C. in 10 seconds as measured by an infrared thermotracer. Subsequently, it was kept at 200 ° C. for 60 seconds to obtain a sizing agent-coated carbon fiber bundle. The adhesion amount of the sizing agent was adjusted to 1 part by mass with respect to 100 parts by mass of the surface-treated carbon fiber. Subsequently, using the obtained sizing agent-coated carbon fibers, one carbon fiber on each of the outside and inside of the carbon fiber bundle was extracted, and the interfacial shear strength (IFSS) was measured. The results are summarized in Table 5-2. As a result, it was found that the outer IFSS of the carbon fiber bundle was 29 MPa and the inner IFSS was 29 MPa, and the adhesion between the outer and inner sides was insufficient.

(Comparative Example 19)
-Step I: Step of producing carbon fiber as a raw material The same as in Example 1.
Step II: Step of attaching sizing agent to carbon fiber (A-2) and (C-2) are mixed at a mass ratio of 100: 3, and acetone is further mixed so that the sizing agent is uniformly dissolved. A 1% by weight acetone solution was obtained. Using an acetone solution of this sizing agent, the sizing agent was applied to the surface-treated carbon fiber by a dipping method, and then irradiated with far infrared rays using a far infrared heating furnace (manufactured by Yamato Scientific Co., Ltd., DIR631). Heating was performed by adjusting the output so that the temperature outside the fiber bundle was 200 ° C. in 10 seconds as measured by an infrared thermotracer. Subsequently, it was kept at 200 ° C. for 60 seconds to obtain a sizing agent-coated carbon fiber bundle. The adhesion amount of the sizing agent was adjusted to 1 part by mass with respect to 100 parts by mass of the surface-treated carbon fiber. Subsequently, using the obtained sizing agent-coated carbon fibers, one carbon fiber on each of the outside and inside of the carbon fiber bundle was extracted, and the interfacial shear strength (IFSS) was measured. The results are summarized in Table 5-2. As a result, it was found that the outer IFSS of the carbon fiber bundle was 26 MPa and the inner IFSS was 25 MPa, and the adhesion between the outer and inner sides was sufficiently high. It was also found that the difference between the outside and the inside was small and the adhesiveness was uniform.

  As described above, the method for producing a sizing agent-coated carbon fiber of the present invention is suitable for processing into a woven fabric or a prepreg that requires excellent bundling and abrasion resistance, and the carbon fiber according to the present invention A carbon fiber reinforced composite material obtained from a matrix resin is lightweight and has excellent strength and elastic modulus. Therefore, it is suitable for many fields such as aircraft members, spacecraft members, automobile members, ship members, civil engineering materials, and sports equipment. Can be used.

Claims (14)

As the component (A), an epoxy compound (A1) having two or more epoxy groups and / or one or more epoxy groups, a hydroxyl group, an amide group, an imide group, a urethane group, a urea group, a sulfonyl group, and sulfo An epoxy compound (A2) having at least one functional group selected from a group is used, and at least one sizing agent selected from the group consisting of the following [a], [b] and [c] is applied A method for producing a sizing agent-coated carbon fiber, wherein the sizing agent-coated carbon fiber is applied to the carbon fiber and heat-treated by microwave irradiation and / or infrared irradiation.
[A] A tertiary amine compound and / or a tertiary amine salt (B1) 0.1 to 25 parts by mass with a molecular weight of 100 g / mol or more used as at least the component (B) with respect to 100 parts by mass of the component (A) A sizing agent formulated with
[B] The following general formula (I) used as at least the component (B) with respect to 100 parts by mass of the component (A)

(Wherein R _{1 to} R ₄ each represent a hydrocarbon group having 1 to 22 carbon atoms, and the hydrocarbon group may have a hydroxyl group, and the CH ₂ group in the hydrocarbon group is- Optionally substituted by O-, -O-CO- or -CO-O-), or general formula (II)

(In the formula, R ₅ represents a hydrocarbon group having 1 to 22 carbon atoms, and the hydrocarbon group may have a hydroxyl group, and the CH ₂ group in the hydrocarbon group represents —O—, — R ₆ and R ₇ each independently represent hydrogen or a hydrocarbon group having 1 to 8 carbon atoms, and CH ₂ group in the hydrocarbon group may be substituted by O—CO— or —CO—O—. Is optionally substituted by —O—, —O—CO— or —CO—O—.) 0.1-25 parts by mass of a quaternary ammonium salt (B2) having a cation moiety A sizing agent formulated with
[C] A sizing agent obtained by blending 0.1 to 25 parts by mass of the quaternary phosphonium salt and / or the phosphine compound (B3) used as the component (B) with respect to 100 parts by mass of the component (A).   2. The method for producing sizing agent-coated carbon fiber according to claim 1, wherein the microwave irradiation and / or the infrared irradiation is heat-treated in a temperature range of 160 ° C. to 260 ° C. for 15 seconds to 600 seconds. The tertiary amine compound and / or tertiary amine salt having a molecular weight of 100 g / mol or more in the above [a] is represented by the following general formula (III)

(In the formula, R ₈ represents a hydrocarbon group having 1 to 22 carbon atoms, and the hydrocarbon group may have a hydroxyl group, and the CH ₂ group in the hydrocarbon group represents —O—, —O, R ₉ may be any one of an alkylene group having 2 to 22 carbon atoms, an alkenylene group having 2 to 22 carbon atoms, or an alkynylene group having 2 to 22 carbon atoms, which may be substituted with —CO— or —CO—O—. R ₁₀ represents hydrogen or a hydrocarbon group having 1 to 22 carbon atoms, and the hydrocarbon group may have a hydroxyl group, and the CH ₂ group in the hydrocarbon group is —O— , -O-CO- or -CO-O-, or R ₈ and R ₁₀ may combine to form an alkylene group having 2 to 11 carbon atoms), a general formula ( IV)

(In the formula, R _{11 to} R ₁₃ each represent a hydrocarbon group having 1 to 22 carbon atoms, and the hydrocarbon group may have a hydroxyl group, and the CH ₂ group in the hydrocarbon group is- Optionally substituted by O-, -O-CO- or -CO-O-), general formula (V)

(In the formula, each of R _{14 to} R ₁₇ represents a hydrocarbon group having 1 to 22 carbon atoms, and the hydrocarbon group may have a hydroxyl group, and the CH ₂ group in the hydrocarbon group is- Optionally substituted by O-, -O-CO- or -CO-O-), general formula (VI)

(In the formula, R _{18 to} R ₂₃ each represent a hydrocarbon group having 1 to 22 carbon atoms, and the hydrocarbon group may have a hydroxyl group, and the CH ₂ group in the hydrocarbon group is- It may be substituted with O-, -O-CO- or -CO-O-, R ₂₄ represents a hydroxyl group or a hydrocarbon group having 1 to 22 carbon atoms, and the hydrocarbon group has a hydroxyl group. And the CH ₂ group in the hydrocarbon group may be substituted by —O—, —O—CO— or —CO—O—), the general formula (VII)

(Wherein R _{25 to} R ₂₇ each represent a hydrocarbon group having 1 to 8 carbon atoms, and the hydrocarbon group may have a hydroxyl group), and general formula (VIII)

(Wherein R ₂₈ represents a hydrocarbon group having 1 to 8 carbon atoms, and the hydrocarbon group may have a hydroxyl group), and any one tertiary amine compound selected from the group consisting of The method for producing carbon fiber coated with a sizing agent according to claim 1, wherein the carbon fiber is a salt of a tertiary amine.   The compound represented by the general formula (III) is 1,5-diazabicyclo [4,3,0] -5-nonene or a salt thereof, or 1,8-diazabicyclo [5,4,0] -7-undecene. Alternatively, the sizing agent-coated carbon fiber production method according to claim 3, wherein the sizing agent-coated carbon fiber is a salt thereof. In the general formula (I) of [b], R ₃ and R ₄ each represent a hydrocarbon group having 2 to 22 carbon atoms, and the hydrocarbon group may have a hydroxyl group, and the hydrocarbon group The method for producing a sizing agent-coated carbon fiber according to claim 1, wherein the CH ₂ group therein may be substituted by -O-, -O-CO- or -CO-O-.   The method for producing sizing agent-coated carbon fiber according to claim 1 or 5, wherein the anion site of the quaternary ammonium salt having the (B2) cation site in [b] is a halogen ion. The (B3) quaternary phosphonium salt and / or phosphine compound of the above [c] is represented by the following general formula (IX)

(In the formula, each of R _{29 to} R ₃₂ represents a hydrocarbon group having 1 to 22 carbon atoms, and the hydrocarbon group may have a hydroxyl group, and the CH ₂ group in the hydrocarbon group is- Optionally substituted by O-, -O-CO- or -CO-O-), or general formula (X)

(Wherein R _{33 to} R ₃₅ each represent a hydrocarbon group having 1 to 22 carbon atoms, and the hydrocarbon group may have a hydroxyl group, and the CH ₂ group in the hydrocarbon group is — The sizing according to claim 1, wherein the sizing is a quaternary phosphonium salt or a phosphine compound which may be substituted by O-, -O-CO- or -CO-O-. A method for producing an agent-coated carbon fiber.   The sizing agent-coated carbon according to claim 1 or 7, wherein 0.1 to 10 parts by mass of (B3) quaternary phosphonium salt and / or phosphine compound is blended with 100 parts by mass of component (A). A method for producing fibers.   The carbon fiber is subjected to liquid phase electrolytic oxidation in an alkaline electrolytic solution, or liquid phase electrolytic oxidation in an acidic electrolytic solution followed by washing with an alkaline aqueous solution, and then a sizing agent is applied. A method for producing carbon fiber coated with a sizing agent according to any one of 8.   The epoxy equivalent of (A) component is less than 360 g / mol, The manufacturing method of the sizing agent application | coating carbon fiber in any one of Claims 1-9 characterized by the above-mentioned.   The method for producing sizing agent-coated carbon fiber according to any one of claims 1 to 10, wherein the component (A) is an epoxy compound having three or more epoxy groups.   (A) A component contains an aromatic ring in a molecule | numerator, The manufacturing method of the sizing agent application | coating carbon fiber in any one of Claims 1-11 characterized by the above-mentioned.   The component (A1) is a phenol novolac type epoxy resin, a cresol novolac type epoxy resin, or tetraglycidyldiaminodiphenylmethane, characterized in that the sizing agent-coated carbon fiber according to any one of claims 1 to 12 is used. Production method.   The sizing agent-coated carbon according to any one of claims 1 to 13, wherein the surface oxygen concentration O / C measured by X-ray photoelectron spectroscopy of the carbon fiber is 0.05 to 0.5. A method for producing fibers.