JP2014145036A - Molding material, method for manufacturing molding material, and carbon fiber-reinforced composite material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a molding material which is excellent interfacial adhesion between a carbon fiber and a thermoplastic resin, and is excellent in mechanical characteristics.SOLUTION: A molding material contains at least a sizing agent-coated carbon fiber in which a carbon fiber is coated with a sizing agent, and a matrix resin. The sizing agent contains at least an aliphatic epoxy compound (A), and an aromatic epoxy compound (B1) as an aromatic compound (B). In the sizing agent-coated carbon fiber, a ratio (a)/(b) between (a) a height (cps) of a component of a binding energy (284.6 eV) attributed to CHx, C-C and C=C of Cinner shell spectrum obtained by measuring the surface of the sizing agent with an X-ray photoelectron spectroscopy at a photoelectron exiting angle of 15°, and (b) a height (cps) of a component of a binding energy (286.1 eV) attributed to C-O is 0.50-0.90. The carbon fiber in the molding material is in a bundle or single fiber state, and is substantially two-dimensionally oriented.

Description

  The present invention relates to a molding material suitably used for aircraft members, spacecraft members, automobile members, ship members, and the like, a method for manufacturing the molding material, and a carbon fiber reinforced composite material.

  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, it is important that the interfacial adhesion between the carbon fibers and the matrix resin is excellent in order to utilize the excellent characteristics of the carbon fibers.

  In order to improve the interfacial adhesion between the carbon fiber and the matrix resin, a method is generally employed in which the carbon fiber is subjected to an oxidation treatment such as gas phase oxidation or liquid phase oxidation, and oxygen-containing functional groups are introduced to the carbon fiber surface. Yes. For example, a method of improving the interlaminar shear strength, which is an index of interfacial 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 interfacial adhesion that can be achieved only by such oxidation treatment 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 a sizing agent to carbon fiber is proposed (refer patent document 2 and 3).

  For example, compounds having a plurality of aliphatic type epoxy groups have been proposed as sizing agents (see Patent Documents 4, 5, and 6). Further, a method of applying an epoxy adduct of polyalkylene glycol as a sizing agent to carbon fibers has been proposed (see Patent Documents 7, 8 and 9).

  In addition, a method of applying diglycidyl ether of bisphenol A to carbon fibers as an aromatic sizing agent 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 10 and 11). In addition, a method of applying a bisphenol A polyalkylene oxide adduct having an epoxy group added thereto to a carbon fiber as a sizing agent has been proposed (see Patent Documents 12 and 13).

  Although the above-described sizing agent can impart adhesion and convergence to the carbon fiber, a sizing agent composed of one kind of epoxy compound is not sufficient, and two or more kinds of epoxy compounds are used in combination depending on the desired function. Techniques have been proposed in recent years.

  For example, a sizing agent in which two or more types of epoxy compounds that define surface energy are combined has been proposed (see Patent Documents 14 to 17). Patent Document 14 discloses a combination of an aliphatic epoxy compound and an aromatic epoxy compound. In Patent Document 14, a sizing agent that is abundant in the outer layer has a blocking effect on the sizing agent component that is abundant in the inner layer, and prevents the epoxy groups from opening due to moisture in the atmosphere. Moreover, in patent document 14, about the preferable range of a sizing agent, the ratio of an aliphatic epoxy compound and an aromatic epoxy compound is prescribed | regulated as 10 / 90-40 / 60, and the one where the quantity of an aromatic epoxy compound is large is considered suitable. ing.

  Patent Documents 16 and 17 disclose sizing agents using two or more epoxy compounds having different surface energies. Since Patent Documents 16 and 17 are intended to improve the adhesiveness with a matrix resin, the combination of an aromatic epoxy compound and an aliphatic epoxy compound is not limited as a combination of two or more epoxy compounds, and the adhesiveness is not limited. There is no general example of the aliphatic epoxy compound selected from the viewpoint of the above.

  Furthermore, the sizing agent which mix | blends a bisphenol A type epoxy compound and aliphatic polyepoxy resin by mass ratio 50 / 50-90 / 10 is disclosed (refer patent document 18). However, Patent Document 18 also has a large amount of bisphenol A type epoxy compound, which is an aromatic epoxy compound.

  In addition, as a sizing agent that defines a combination of an aromatic epoxy compound and an aliphatic epoxy compound, a polyfunctional aliphatic compound on the surface of the carbon fiber bundle, an epoxy resin on the upper surface, an alkylene oxide adduct and an unsaturated dibasic acid A combination of a condensate and an alkylene oxide adduct of phenols is disclosed (see Patent Document 19).

  Furthermore, as a combination of two or more epoxy compounds, a combination of an aliphatic epoxy compound and a bisphenol A type epoxy compound that is an aromatic epoxy compound is disclosed. The aliphatic epoxy compound is a cycloaliphatic epoxy compound and / or a long-chain aliphatic epoxy compound (see Patent Document 20).

  Further, combinations of epoxy compounds having different properties are disclosed. A combination of two epoxy compounds that are liquid and solid at 25 ° C. is disclosed (see Patent Document 21). Furthermore, combinations of epoxy resins having different molecular weights, and combinations of monofunctional aliphatic epoxy compounds and epoxy resins have been proposed (see Patent Documents 22 and 23).

  However, in order to improve the physical properties of a molding material containing sizing agent-coated carbon fibers and a matrix resin such as a thermoplastic resin, a sizing agent (for example, Patent Documents 20 to 23) in which two or more of the above are mixed is sufficient. I couldn't say that. In order to satisfy the high adhesion between carbon fiber and thermoplastic resin, it is considered necessary to satisfy the following two requirements, but a sizing agent consisting of a combination of any conventional epoxy resin does not meet these requirements. It is presumed that there was not. The first of the two requirements is that an epoxy compound with high adhesion exists inside the sizing layer (carbon fiber side), and the carbon fiber and the epoxy compound interact strongly, and the second is the sizing layer. The surface layer (the thermoplastic resin side which is the matrix resin) needs to have a chemical composition capable of strong interaction with the epoxy compound having high adhesion to the carbon fiber in the inner layer and the thermoplastic resin in the outer layer.

  For example, Patent Document 14 discloses that the sizing agent has an inclined structure in order to enhance the adhesion between the carbon fiber and the sizing agent, but Patent Document 14 and any other documents (Patent Documents 15 to 15). 18), in the molding material containing the sizing agent-coated carbon fiber and the thermoplastic resin, a component having high adhesiveness is disposed on the inner layer of the sizing layer, and a component having high interaction with the thermoplastic resin is disposed on the surface layer of the sizing layer. It can be said that there is no idea to improve the interfacial adhesion between the carbon fiber and the thermoplastic resin by arranging them.

  Patent Document 19 discloses that a polyfunctional aliphatic compound is present in the inner layer of the sizing agent and an aromatic epoxy resin and an aromatic reactant having low reactivity are present in the outer layer. However, it can be said that it is difficult to achieve high adhesiveness because the aliphatic compound and the aromatic compound are separated.

  As described above, in the conventional technique, particularly when a thermoplastic resin is used as the matrix resin, the interfacial adhesion with the carbon fiber is poor, and a further interfacial adhesion improving technique is required.

Japanese Patent Laid-Open No. 04-361619 US Pat. No. 3,957,716 JP-A-57-171767 Japanese Examined Patent Publication No. 63-14114 Japanese Patent Laid-Open No. 07-279040 JP 08-113876 A JP-A-57-128266 U.S. Pat. No. 4,555,446 JP 62-033872 A JP 07-009444 A JP 2000-336577 A JP 61-028074 A Japanese Patent Laid-Open No. 01-272867 JP 2005-179826 A JP 2005-256226 A International Publication No. 03/010383 JP 2008-280624 A JP 2005-213687 A JP 2002-309487 A Japanese Patent Laid-Open No. 02-307979 JP 2002-173873 A JP 59-71479 A JP 58-41973 A

  Therefore, in view of the above-mentioned problems in the prior art, the object of the present invention is a molding material excellent in interfacial adhesion between carbon fiber and matrix resin, and excellent in mechanical properties under wet conditions, a method for producing the molding material, and carbon fiber reinforcement It is to provide a composite material.

  The inventors of the present invention have a sizing agent surface of a carbon fiber coated with a sizing agent in which a plurality of specific compounds are combined, the sizing agent-coated carbon fiber having a specific chemical composition, and a matrix resin. It has been found that the above-mentioned object can be achieved in a molding material in which carbon fibers are bundled or single fibers and are substantially two-dimensionally oriented. That is, in the present invention, a known sizing agent can be used as the individual sizing agent itself, but in the combination of specific compounds, the sizing agent-coated carbon fiber sizing agent surface has a specific chemical composition. It is an important technique and can be said to be novel.

The present invention employs the following means in order to solve the above problems. That is, the present invention is a molding material comprising a sizing agent-coated carbon fiber in which at least carbon fiber is coated with a sizing agent and a matrix resin, wherein the sizing agent includes an aliphatic epoxy compound (A) and an aromatic compound. (B) contains at least an aromatic epoxy compound (B1), and the sizing agent-coated carbon fiber uses AlKα _1,2 with the surface of the sizing agent as an X-ray source, by X-ray photoelectron spectroscopy. The height (cps) of the component of the binding energy (284.6 eV) attributed to (a) CHx, C—C, C = C of the C _1s inner shell spectrum measured at a photoemission angle of 15 °, (b ) The ratio (a) / (b) of the binding energy (286.1 eV) attributed to C—O to the height (cps) of the component is 0.50 to 0.90. The carbon fibers in the molding composition is characterized in that it is substantially aligned two-dimensionally in a bundle or single fiber.

  The molding material according to the present invention is characterized in that, in the above invention, the sizing agent-coated carbon fiber has a moisture content of 0.010 to 0.030% by mass.

  In the molding material of the present invention, the mass ratio of the aliphatic epoxy compound (A) and the aromatic epoxy compound (B1) in the sizing agent is 52/48 to 80/20. And

  In the molding material of the present invention, in the above invention, the aliphatic epoxy compound (A) is a polyether type polyepoxy compound and / or a polyol type polyepoxy compound having two or more epoxy groups in the molecule. Features.

  Further, the molding material of the present invention is the above invention, wherein the aliphatic epoxy compound (A) is 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, glycerol, diglycerol, polyglycerol, trimethylolpropane, pentaerythritol , Characterized in that sorbitol, and a arabitol, glycidyl ether type epoxy compound obtained by reaction with epichlorohydrin.

  The molding material of the present invention is characterized in that, in the above invention, the aromatic epoxy compound (B1) is a bisphenol A type epoxy compound or a bisphenol F type epoxy compound.

In the molding material of the present invention, the sizing agent-coated carbon fiber is measured at a photoelectron escape angle of 55 ° by X-ray photoelectron spectroscopy using 400 eV X-rays. Of the C1s inner shell spectrum (a) the height (cps) of the component of the binding energy (284.6 eV) attributed to CHx, CC, C = C, and (b) the bond attributed to CO The values of (I) and (II) obtained from the ratio (a) / (b) with the height (cps) of the component of energy (286.1 eV) satisfy the relationship of (III) Features.
(I) Value of (a) / (b) on the surface of the sizing agent-coated carbon fiber before sonication (II) Sizing agent adhesion by sonicating the sizing agent-coated carbon fiber in an acetone solvent (A) / (b) value (III) 0.50 ≦ (I) ≦ 0.90 and 0.60 <on the surface of the sizing agent-coated carbon fiber washed to 0.09 to 0.20% by mass (II) / (I) <1.0

  Further, the molding material of the present invention is the sizing agent on the surface of the carbon fiber coated with the sizing agent by ultrasonicating the molding material in a solvent that dissolves the matrix resin constituting the molding material. The surface of the carbon fiber coated with the sizing agent, which has been washed to an adhesion amount of 0.09 to 0.20% by mass, is measured in the C1s measured at a photoelectron escape angle of 55 ° by X-ray photoelectron spectroscopy using 400 eV X-rays. The height (cps) of the component of the binding energy (284.6 eV) attributed to (a) CHx, C—C, C═C of the shell spectrum, and (b) the binding energy (286) attributed to C—O. .1 eV) component height (cps) ratio (a) / (b) is 0.30 to 0.70.

  The molding material of the present invention is characterized in that, in the above invention, the amount of the aliphatic epoxy compound (A) attached is 0.2 to 2.0% by mass.

  Further, the molding material of the present invention is the above invention, wherein the surface carboxyl group concentration COOH / C measured by chemical modification X-ray photoelectron spectroscopy of the carbon fiber is 0.003 to 0.015, and the surface hydroxyl group concentration COH / C. Is 0.001 to 0.050.

  The molding material of the present invention is characterized in that, in the above invention, the matrix resin is a thermoplastic resin.

  Further, the molding material of the present invention is the above invention, wherein the thermoplastic resin is a polyarylene sulfide resin, a polyether ether ketone resin, a polyphenylene ether resin, a polyoxymethylene resin, a polyester resin, a polycarbonate resin, a polystyrene resin, and the like. It is at least one selected from polyolefin resins.

  The molding material of the present invention is characterized in that, in the above invention, the thermoplastic resin is polyamide.

  The molding material of the present invention is characterized in that, in the above invention, the matrix resin is a thermosetting resin.

  The molding material of the present invention is characterized in that, in the above invention, the thermosetting resin is a radical polymerization resin.

  The molding material of the present invention is characterized in that, in the above invention, the molding material is in a web shape, a nonwoven fabric shape, a felt shape, or a mat shape.

  The present invention also provides a molding material manufacturing method for manufacturing the molding material according to any one of the above, wherein the carbon fiber is processed into a web-like, non-woven fabric, felt-like, or mat-like fabric. With respect to 100 parts by mass of the dough obtained in the processing step and the processing step, 35 to 65% by mass of the aliphatic epoxy compound (A) and 35 to 65% of the aromatic compound (B) with respect to the total amount of the sizing agent excluding the solvent. An application step of applying 0.1 to 10 parts by mass of a sizing agent containing at least 60% by mass, and a matrix resin of 20 to 99% by mass with respect to 1 to 80% by mass of the dough provided with the sizing agent in the application step. It is characterized by including a compounding step of applying and compounding.

  Further, the present invention is a method for producing a molding material for producing the molding material according to any one of the above, and is aliphatic with respect to 100 parts by mass of the carbon fiber relative to the total amount of the sizing agent excluding the solvent An application step of obtaining 0.1 to 10 parts by mass of a sizing agent containing at least 35 to 65% by mass of an epoxy compound (A) and 35 to 60% by mass of an aromatic compound (B) to obtain a sizing agent-coated carbon fiber; A cutting step for cutting the sizing agent-coated carbon fibers obtained in the coating step into 1 to 50 mm, a sizing agent-coated carbon fiber cut in the cutting step in an amount of 1 to 80% by mass, and a matrix resin in an amount of 20 to 99% by mass. And a compounding step of mixing and compounding.

  Moreover, the carbon fiber reinforced composite material of the present invention is formed by molding the molding material according to any one of the above, or the molding material manufactured by any of the methods described above. .

The molding material and the manufacturing method of the molding material according to the present invention are obtained by applying a sizing agent containing at least an aromatic epoxy compound (B1) as an aliphatic epoxy compound (A) and an aromatic compound (B) to carbon fibers, and sizing By making the surface of the sizing agent of the agent-coated carbon fiber have a specific chemical composition, the interfacial adhesion between the carbon fiber and the matrix resin can be improved, and high mechanical properties can be maintained even under wet conditions.
Further, since the carbon fiber reinforced composite material of the present invention is lightweight and has excellent strength and elastic modulus, it is suitable for many fields such as aircraft members, spacecraft members, automobile members, ship members, civil engineering and building materials and sports equipment. Can be used.

  Hereinafter, in more detail, the form for implementing the molding material of this invention, the manufacturing method of a molding material, and a carbon fiber reinforced composite material is demonstrated.

The present invention is a molding material comprising at least a sizing agent-coated carbon fiber in which a sizing agent is applied to carbon fibers and a matrix resin, and the sizing agent includes an aliphatic epoxy compound (A) and an aromatic compound (B). ) And at least the aromatic epoxy compound (B1), and the sizing agent-coated carbon fiber has a photoelectron escape angle by X-ray photoelectron spectroscopy using AlKα _1,2 using the sizing agent surface as an X-ray source. The height (cps) of the component of the binding energy (284.6 eV) attributed to (a) CHx, C-C, C = C in the C _1s core spectrum measured at 15 °, and (b) C- The ratio (a) / (b) of the binding energy (286.1 eV) attributed to O to the height (cps) of the component is 0.50 to 0.90, Carbon fiber in is the molding material characterized in that it is substantially aligned two-dimensionally in a bundle or single fiber.

  According to the knowledge of the present inventors, those in such a range have a high interfacial adhesion between the carbon fiber and the matrix resin, have excellent mechanical properties, and use a highly hygroscopic resin as the matrix resin. In addition, it is possible to obtain a carbon fiber reinforced composite material in which deterioration of physical properties under moisture is suppressed.

  Carbon fiber coated with a sizing agent composed only of an aliphatic epoxy compound (A) as an epoxy compound has a strong interaction between the carbon fiber and the sizing agent and has good adhesiveness. Therefore, a carbon fiber reinforced composite material using the carbon fiber is used. It has been confirmed that the physical properties of the film become good. Although the mechanism is not certain, the aliphatic epoxy compound (A) is derived from a flexible skeleton and a structure having a high degree of freedom, so that a functional group such as a carboxyl group and a hydroxyl group on the surface of the carbon fiber and an aliphatic that is a sizing agent It is considered that the epoxy compound (A) can form a strong interaction. However, while the aliphatic epoxy compound (A) exhibits high adhesiveness due to the interaction with the carbon fiber surface, the aliphatic epoxy compound (A) has a strong interaction with water due to its structure. Carbon fiber coated with a sizing agent consisting of only high moisture content, especially when a highly hygroscopic resin is used, it is confirmed that the molding material containing this has a problem that the physical properties under wetness are slightly reduced Has been.

  On the other hand, a molding material comprising a carbon fiber and a matrix resin coated with a sizing agent composed only of an aromatic epoxy compound (B1) and not containing an aliphatic epoxy compound (A) as an epoxy compound forms a rigid interface layer. There is an advantage that you can. In addition, there is an advantage that the sizing agent is highly hydrophobic and the moisture content of the carbon fiber surface can be lowered. However, since the aromatic epoxy compound (B1) is derived from the rigidity of the compound and the interaction between the carbon fiber and the sizing agent is slightly inferior to the aliphatic epoxy compound (A), molding using the aromatic epoxy compound (B1) It has been confirmed that the mechanical properties of the material are slightly inferior.

  In the present invention, when a sizing agent in which an aliphatic epoxy compound (A) and an aromatic compound (B) are mixed is used, the aliphatic epoxy compound (A) having higher polarity is unevenly distributed on the carbon fiber side, and the carbon fiber It is important that the phenomenon that the aromatic compound (B) having a low polarity tends to be unevenly distributed is found in the outermost layer of the sizing layer on the opposite side. As a result of the gradient structure of the sizing layer, the aliphatic epoxy compound (A) has a strong interaction with the carbon fiber in the vicinity of the carbon fiber, and the aromatic compound (B) having a low polarity has a strong interaction with the matrix resin. As a result, the interfacial adhesion between the carbon fiber and the matrix resin can be enhanced, and the physical properties of the obtained carbon fiber reinforced composite material can be enhanced. Moreover, the aromatic compound (B) which exists abundantly in an outer layer plays the role which reduces the moisture content of carbon fiber vicinity in a molding material or a carbon fiber reinforced composite material. As a result, even when a highly hygroscopic resin is used as the matrix resin, the moisture content in the vicinity of the carbon fibers becomes low when wet, so that the deterioration of the physical properties of the carbon fiber reinforced composite material obtained from the molding material is suppressed. The Therefore, the abundance ratio of the aliphatic epoxy compound (A) and the aromatic compound (B) on the sizing agent surface layer measured by X-ray photoelectron spectroscopy is important.

  The sizing agent used in the present invention contains at least the aliphatic epoxy compound (A) and the aromatic compound (B). It is preferable that 35-65 mass% of an aliphatic epoxy compound (A) is contained with respect to the apply | coated sizing agent whole quantity. When the aliphatic epoxy compound (A) is applied to the carbon fibers at a ratio of 35% by mass or more, the interfacial adhesion with the matrix resin is improved, and the physical properties of the carbon fiber reinforced composite material are improved. Moreover, components other than the aliphatic epoxy compound (A) can be used as the sizing agent when the amount is 65% by mass or less, and the interaction between the sizing agent and the matrix resin is increased, thereby obtaining the molding material. The physical properties of the carbon fiber reinforced composite material are improved. The proportion of the aliphatic epoxy compound (A) is more preferably 38% by mass or more, and further preferably 40% by mass or more. The proportion of the aliphatic epoxy compound (A) is more preferably 60% by mass or less, and further preferably 55% by mass or more.

  It is preferable that 35-60 mass% of aromatic compounds (B) are contained with respect to the applied sizing agent total amount. By containing 35% by mass or more of the aromatic compound (B), the composition of the aromatic compound (B) in the outer layer of the sizing agent can be maintained high, so that the interaction with the matrix resin becomes strong and the molding material The moisture content near the carbon fiber in the carbon fiber reinforced composite material obtained from the above can be lowered. It is preferable that the ratio of the aromatic compound (B) is 60% by mass or less because the above-described inclined structure in the sizing agent can be expressed and the adhesiveness can be maintained. The proportion of the aromatic compound (B) is more preferably 37% by mass or more, and further preferably 39% by mass or more. The proportion of the aromatic compound (B) is more preferably 55% by mass or less, and further preferably 45% by mass or more.

  The epoxy component in the sizing agent in the present invention includes an aliphatic epoxy compound (A) and an aromatic epoxy compound (B1) that is an aromatic compound (B). The mass ratio (A) / (B1) between the aliphatic epoxy compound (A) and the aromatic epoxy compound (B1) in the sizing agent is preferably 52/48 to 80/20. When (A) / (B1) is 52/48 or more, the ratio of the aliphatic epoxy compound (A) present on the carbon fiber surface is increased, and the interfacial adhesion with the carbon fiber is improved. As a result, the composite physical properties such as the bending strength of the carbon fiber reinforced composite material are increased, which is preferable. Moreover, when the mass ratio (A) / (B1) of the aliphatic epoxy compound (A) and the aromatic epoxy compound (B1) is 80/20 or less, the aliphatic epoxy compound having a high moisture content is reinforced with carbon fiber. This is preferable because the amount of the composite material present on the carbon fiber surface decreases and the amount of the aromatic compound (B) capable of interacting with the matrix resin increases. The mass ratio of (A) / (B1) is more preferably 55/45 or more, and still more preferably 60/40 or more. Moreover, 75/35 or less is more preferable, and 73/37 or less is further more preferable.

Moreover, in this invention, it is preferable that the surface tension in 125 degreeC of an aliphatic epoxy compound (A) and an aromatic epoxy compound (B1) is 35-45 mJ / m < ² >. By combining the aliphatic epoxy compound (A) and the aromatic epoxy compound (B1) whose surface tensions are close to each other, the mixing property of the two types of compounds is improved, and at the time of storing the carbon fiber coated with the sizing agent, Generation | occurrence | production of the bleed-out etc. of a sizing agent component can be suppressed.

  Here, in the present invention, the surface tension value at 125 ° C. of the aliphatic epoxy compound (A) and the aromatic epoxy compound (B1) can be obtained by the Wilhelmi method using a platinum plate by the following method. It is.

  When a platinum plate is brought into contact with a sizing solution that is composed of only the components and is adjusted to a temperature of 125 ° C., the sizing solution wets the platinum plate. At this time, surface tension acts along the periphery of the plate, and the plate is sized. Try to pull into the liquid. This force is read and calculated. For example, it can be measured as a static surface tension using a surface tension meter DY-500 manufactured by Kyowa Interface Science Co., Ltd.

  The aliphatic epoxy compound (A) used in the present invention is an epoxy compound containing no aromatic ring. Since it has a flexible skeleton with a high degree of freedom, it can have a strong interaction with carbon fibers. As a result, the interfacial adhesion with the carbon fiber coated with the sizing agent is improved, and the physical properties of the carbon fiber reinforced composite material using the same are improved.

  In the present invention, the aliphatic epoxy compound (A) has one or more epoxy groups in the molecule. Thereby, a strong bond between the carbon fiber and the epoxy group in the aliphatic epoxy compound (A) can be formed. The number of epoxy groups in the molecule is preferably 2 or more, and more preferably 3 or more. When the epoxy compound has two or more epoxy groups in the molecule, even if one epoxy group forms a covalent bond with the oxygen-containing functional group on the surface of the carbon fiber, the remaining epoxy group is the aromatic epoxy of the outer layer. A covalent bond or a hydrogen bond can be formed with the compound (B1) or the matrix resin, and the adhesiveness is further improved, which is preferable. There is no particular upper limit on the number of epoxy groups, but 10 is sufficient because the interfacial adhesion may be saturated.

  In the present invention, the aliphatic epoxy compound (A) is preferably an epoxy compound having 3 or more of 2 or more types of functional groups, and more preferably an epoxy compound having 4 or more of 2 or more types of functional groups. . The functional group possessed by the aliphatic epoxy compound (A) 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. In the case of the aliphatic epoxy compound (A) having three or more epoxy groups or other functional groups in the molecule, even when one epoxy group forms a covalent bond with the oxygen-containing functional group on the carbon fiber surface, The remaining two or more epoxy groups or other functional groups can form a covalent bond or a hydrogen bond with the aromatic epoxy compound (B1) or the matrix resin, and the adhesion is further improved. There is no particular upper limit on the number of functional groups containing an epoxy group, but 10 is sufficient from the viewpoint of adhesiveness.

  In the present invention, the epoxy equivalent of the aliphatic epoxy compound (A) is 360 g / eq. Is preferably less than 270 g / eq. Less, more preferably 180 g / eq. Is less than. Epoxy equivalent is 360 g / eq. If it is less than the above, the interaction with the carbon fiber is formed at a high density, and the interfacial adhesion with the carbon fiber is further improved. Moreover, there is no particular lower limit of the epoxy equivalent of the aliphatic epoxy compound (A), but the interface adhesiveness may be saturated, so that 90 g / eq. That's enough.

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

  Examples of the glycidyl ether type epoxy compound include a glycidyl ether type epoxy compound obtained by a reaction with epichlorohydrin. Further, as glycidyl ether type epoxy compounds, 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, pen Erythritol, sorbitol or a arabitol, glycidyl ether type epoxy compound obtained by reaction of epichlorohydrin are also exemplified. Examples of the glycidyl ether type epoxy compound include a glycidyl ether type epoxy compound having a dicyclopentadiene skeleton.

Examples of the glycidylamine type epoxy compound include 1,3-bis (aminomethyl) cyclohexane.
Examples of the glycidyl ester type epoxy compound include a glycidyl ester type epoxy compound obtained by reacting dimer acid with epichlorohydrin.

Examples of the epoxy compound obtained by oxidizing a compound having a plurality of double bonds in the molecule include an epoxy compound having an epoxycyclohexane ring in the molecule. Furthermore, the epoxy compound includes epoxidized soybean oil.
In addition to these epoxy compounds, an epoxy compound such as triglycidyl isocyanurate can be used as the aliphatic epoxy compound (A) used in the present invention.

  The aliphatic epoxy compound (A) in the present invention is selected from one or more epoxy groups and a hydroxyl group, an amide group, an imide group, a urethane group, a urea group, a sulfonyl group, a carboxyl group, an ester group, and a sulfo group, It preferably has one or more functional groups. Specific examples of the aliphatic epoxy compound (A) 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 an epoxy A compound having a 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 a hydroxyl group in addition to the epoxy 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 amide group in addition to the epoxy group include an amide-modified epoxy compound. The amide-modified epoxy can be obtained by reacting an epoxy group of an epoxy compound having two or more epoxy groups with a carboxyl group of an aliphatic dicarboxylic acid amide.

  Examples of the compound having a urethane group in addition to the epoxy group include a urethane-modified epoxy compound. 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 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 compound. Can be obtained. Here, examples of the polyvalent isocyanate used include hexamethylene diisocyanate, isophorone diisocyanate, and norbornane diisocyanate.

  Examples of the compound having a urea group in addition to the epoxy group include a urea-modified epoxy compound. A urea-modified epoxy can be obtained by reacting an epoxy group of an epoxy compound having two or more epoxy groups with a carboxyl group of an aliphatic dicarboxylic acid urea.

  The aliphatic epoxy compound (A) used in the present invention is ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, tripropylene from the viewpoint of obtaining high adhesiveness among the above-mentioned. Glycol, tetrapropylene glycol, polypropylene glycol, trimethylene glycol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, polybutylene glycol, 1,5-pentane Diol, neopentyl glycol, 1,6-hexanediol, glycerol, diglycerol, polyglycerol, trimethylolpropane, pentaerythritol, sorbitol, or alcohol And Bitoru, glycidyl ether type epoxy compound obtained by reaction of epichlorohydrin is more preferable.

  Among the above, the aliphatic epoxy compound (A) in the present invention is preferably a polyether type polyepoxy compound and / or a polyol type polyepoxy compound having two or more epoxy groups in the molecule from the viewpoint of high adhesiveness.

  In addition, the aliphatic epoxy compound (A) is 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, glycerol, diglycerol, polyglycerol, trimethylolpropane, pentaerythritol, sorbitol, or arabitol; More preferably glycidyl ether type epoxy compound obtained by reaction of the chlorohydrin.

  In the present invention, the aliphatic epoxy compound (A) is more preferably polyglycerol polyglycidyl ether.

  In the present invention, the aromatic compound (B) is a compound having one or more aromatic rings in the molecule. The aromatic ring may be an aromatic ring hydrocarbon composed only of carbon, or a heteroaromatic ring such as furan, thiophene, pyrrole or imidazole containing a heteroatom such as nitrogen or oxygen. The aromatic ring may be a polycyclic aromatic ring such as naphthalene or anthracene. In a carbon fiber reinforced composite material composed of a carbon fiber coated with a sizing agent and a matrix resin, the so-called interface layer in the vicinity of the carbon fiber is affected by the carbon fiber or the sizing agent and may have different characteristics from the matrix resin. is there. When the aromatic compound (B) 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 bending strength of the carbon fiber reinforced composite material is increased. Mechanical properties are improved. In particular, when a highly hydrophobic resin containing a large amount of aromatic rings or hydrocarbons is used as the matrix resin, it is preferable because the interaction with the aromatic compound (B) contained in the sizing agent is high and the adhesiveness is improved. . In addition, since an epoxy compound having an aromatic ring has high heat resistance, even if it is a thermoplastic resin having a high molding temperature such as polyarylene sulfide resin, it does not disappear due to thermal decomposition, and the original carbon fiber surface It is possible to maintain the function of the reaction with the oxygen-containing functional group and the interaction with the matrix resin. In addition, because the hydrophobicity is improved by the aromatic ring, the moisture content in the vicinity of the carbon fiber can be reduced, so even when a highly hygroscopic matrix resin is used, the physical properties of the carbon fiber composite material are reduced under wet conditions. Is preferable. It is preferable to have two or more aromatic rings because the above-described effects of the aromatic ring are enhanced. There is no particular upper limit on the number of aromatic rings, but ten is sufficient because the mechanical properties may be saturated.

  In the present invention, the aromatic compound (B) can have one or more functional groups in the molecule. Moreover, the aromatic compound (B) used for a sizing agent may be one kind, and may be used in combination of a some compound. When a plurality of aromatic compounds (B) are used for the sizing agent, at least one of the aromatic compounds (B) to be used has a fragrance having one or more epoxy groups and one or more aromatic rings in the molecule. Group epoxy compound (B1). The functional group that the aromatic compound (B) has in the molecule is selected from a hydroxyl group, an amide group, an imide group, a urethane group, a urea group, a sulfonyl group, a carboxyl group, an ester group, or a sulfo group in addition to the epoxy group. It is preferable that two or more kinds may be contained in one molecule. It is preferable to use an epoxy group or a functional group other than an epoxy group because it can interact with the matrix resin. The aromatic compound (B) used for the sizing agent, in addition to the aromatic epoxy compound (B1), improves the stability and higher processability of the compound. Preferably used.

  In the present invention, the number of epoxy groups of the aromatic epoxy compound (B1) is preferably 2 or more, and more preferably 3 or more. Also, 10 or less is sufficient.

  In the present invention, the aromatic epoxy compound (B1) is preferably an epoxy compound having 3 or more functional groups of 2 or more, more preferably an epoxy compound having 4 or more of 2 or more functional groups. . The functional group possessed by the aromatic epoxy compound (B1) 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. In the case of an epoxy compound having three or more epoxy groups and other functional groups in the molecule, even if one epoxy group forms a covalent bond with an oxygen-containing functional group on the surface of the carbon fiber, the remaining two or more These epoxy groups or other functional groups can form interactions such as covalent bonds and hydrogen bonds with the matrix resin, and the interfacial adhesion with the matrix resin is further improved. There is no particular upper limit on the number of functional groups including an epoxy group, but 10 is sufficient from the viewpoint of interfacial adhesion saturation.

  In the present invention, the epoxy equivalent of the aromatic epoxy compound (B1) is 360 g / eq. Is preferably less than 270 g / eq. Less, more preferably 180 g / eq. Is less than. The epoxy equivalent of the aromatic epoxy compound (B1) is 360 g / eq. If it is less than the range, covalent bonds are formed at high density, and the interfacial adhesion with the carbon fiber, aliphatic epoxy compound (A) or matrix resin is further improved, which is preferable. There is no particular lower limit of the epoxy equivalent of the aromatic epoxy compound (B1), but 90 g / eq. The above is sufficient from the viewpoint of saturation of the interfacial adhesion.

  In the present invention, specific examples of the aromatic epoxy compound (B1) include, for example, a glycidyl ether type epoxy compound derived from a polyol, a glycidyl amine type epoxy compound derived from an amine having a plurality of active hydrogens, and a polycarboxylic acid. Examples thereof include an induced glycidyl ester type epoxy compound and an epoxy compound obtained by oxidizing a compound having a plurality of double bonds in the molecule.

  Examples of the glycidyl ether type epoxy compound 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. Examples of the glycidyl ether type epoxy compound include a glycidyl ether type epoxy compound having a biphenylaralkyl skeleton.

  Examples of the glycidylamine type epoxy compound include N, N-diglycidylaniline, N, N-diglycidyl-o-toluidine, m-xylylenediamine, m-phenylenediamine, 4,4′-diaminodiphenylmethane and 9,9. -Bis (4-aminophenyl) fluorene.

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

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

  In addition to these epoxy compounds, the aromatic epoxy compound (B1) used in the present invention is an epoxy compound synthesized from the above-mentioned epoxy compound, for example, oxazolidone from bisphenol A diglycidyl ether and tolylene diisocyanate. An epoxy compound synthesized by a ring formation reaction is exemplified.

  In the present invention, the aromatic epoxy compound (B1) is selected from a hydroxyl group, an amide group, an imide group, a urethane group, a urea group, a sulfonyl group, a carboxyl group, an ester group, and a sulfo group in addition to one or more epoxy groups. An aromatic epoxy compound (B1) having at least one functional group is preferably used. For example, compounds having epoxy group and hydroxyl group, compounds having epoxy group and amide group, compounds having epoxy group and imide group, compounds having epoxy group and urethane group, compounds having epoxy group and urea group, epoxy group and sulfonyl Examples thereof include compounds having a group and compounds having an epoxy group and a sulfo group.

  Examples of the aromatic epoxy compound (B1) having an amide group in addition to the epoxy group include glycidyl benzamide and an amide-modified epoxy compound. The amide-modified epoxy compound can be obtained by reacting an epoxy group of an epoxy compound having two or more epoxy groups with a carboxyl group of a dicarboxylic acid amide containing an aromatic ring.

  Examples of the aromatic epoxy compound (B1) having an imide group in addition to the epoxy group include glycidyl phthalimide. Specific examples include “Denacol (registered trademark)” EX-731 (manufactured by Nagase ChemteX Corporation).

  As the aromatic epoxy compound (B1) having a urethane group in addition to the epoxy group, the terminal hydroxyl group of the polyethylene oxide monoalkyl ether is reacted with a polyvalent isocyanate containing an aromatic ring equivalent to the amount of the hydroxyl group, and then obtained. It can obtain by making the isocyanate residue of the obtained reaction product react with the hydroxyl group in a polyhydric epoxy compound. Here, examples of the polyvalent isocyanate used include 2,4-tolylene diisocyanate, metaphenylene diisocyanate, paraphenylene diisocyanate, diphenylmethane diisocyanate, triphenylmethane triisocyanate, and biphenyl-2,4,4′-triisocyanate. It is done.

Examples of the aromatic epoxy compound (B1) having a urea group in addition to the epoxy group include a urea-modified epoxy compound. The urea-modified epoxy can be obtained by reacting the epoxy group of an epoxy compound containing an aromatic ring having two or more epoxy groups with the carboxyl group of the dicarboxylic acid urea.
Examples of the aromatic epoxy compound (B1) having a sulfonyl group in addition to the epoxy group include a bisphenol S-type epoxy compound.

  Examples of the aromatic epoxy compound (B1) having a sulfo group in addition to the epoxy group include glycidyl p-toluenesulfonate and glycidyl 3-nitrobenzenesulfonate.

  In the present invention, the aromatic epoxy compound (B1) is preferably a phenol novolac type epoxy compound, a cresol novolac type epoxy compound, tetraglycidyl diaminodiphenylmethane, a bisphenol A type epoxy compound or a bisphenol F type epoxy compound. Since these aromatic epoxy compounds (B1) have a large number of epoxy groups, they have a small epoxy equivalent, and thus have a strong interaction with carbon fibers, aliphatic epoxy compounds (A), and matrix resins, and have an interfacial adhesive property. It is preferable because the mechanical properties such as bending strength of the carbon fiber reinforced composite material obtained from the molding material are improved and the mechanical properties when wet are improved because the ratio of aromatic rings is high. The aromatic epoxy compound (B1) is more preferably a bisphenol A type epoxy compound or a bisphenol F type epoxy compound.

  Furthermore, the sizing agent used in the present invention may contain one or more components other than the aliphatic epoxy compound (A) and the aromatic epoxy compound (B1) that is the aromatic compound (B). Adhesion promoting component that enhances the adhesion between carbon fiber and sizing agent, and by adding convergence or flexibility to carbon fiber coated with sizing agent, handling property, scratch resistance and fluff resistance are improved, and matrix A sizing agent that improves the impregnation property of the resin can be blended. In addition, auxiliary components such as a dispersant and a surfactant may be added for the purpose of improving the physical properties of the carbon fiber composite material obtained from the molding material according to the present invention.

  In addition to the aliphatic epoxy compound (A) and the aromatic epoxy compound (B1), the sizing agent used in the present invention is an ester compound (C) that does not have an epoxy group in the molecule, and the total amount of the sizing agent excluding the solvent. It can contain 2 to 35 mass% with respect to it. The content ratio is more preferably 15 to 30% by mass. When the sizing agent contains the ester compound (C), the convergence of the carbon fiber is improved and the handleability is improved. Further, when the aromatic ester compound (C1) is used as the ester compound (C), the hydrophobicity in the vicinity of the carbon fiber is increased, and the mechanical properties under wet conditions are increased, which is preferable. The aromatic ester compound (C1) is contained in the aromatic compound (B) in the present invention at the same time as the ester compound (C) having no epoxy compound in the molecule (in this case (B) Not all are (C1), and (B) includes (B1) and (C1) as described above). Use of the aromatic ester compound (C1) as the ester compound (C) is preferable because the handleability of the carbon fiber coated with the sizing agent is improved. Further, the ester compound (C) can have a functional group other than the ester group, and has an hydroxyl group, an amide group, an imide group, a urethane group, a urea group, a sulfonyl group, a carboxyl group, and a sulfo group (C ) Is preferred. As the aromatic ester compound (C1), specifically, an ester compound composed of a condensate of an alkylene oxide adduct of bisphenols and an unsaturated dibasic acid is preferably used. The unsaturated dibasic acid includes an acid anhydride lower alkyl ester, and fumaric acid, maleic acid, citraconic acid, itaconic acid and the like are preferably used. As the alkylene oxide adduct of bisphenols, ethylene oxide, propylene oxide, butylene oxide, etc. of bisphenol are preferably used. Among the condensates, a condensate of fumaric acid or maleic acid and bisphenol A ethylene oxide or / and propylene oxide adduct is preferably used.

  The method for adding alkylene oxide to bisphenols is not limited, and known methods can be used. If necessary, the unsaturated dibasic acid mentioned above contains a saturated dibasic acid or a small amount of monobasic acid, and the bisphenol alkylene oxide adduct contains ordinary glycol, polyether glycol and a small amount. Polyhydric alcohols, monohydric alcohols, and the like can be added as long as the properties such as adhesion are not impaired. A known method can be used as the condensation method of the alkylene oxide adduct of bisphenol and the unsaturated dibasic acid.

  In this invention, it is preferable to use the component which accelerates | stimulates adhesiveness for the purpose of improving the adhesiveness of carbon fiber and the epoxy compound in a sizing agent component, and improving the interface adhesiveness of carbon fiber and a matrix resin. As a component that promotes adhesion, at least one compound selected from a tertiary amine compound and / or a tertiary amine salt, a quaternary ammonium salt having a cation moiety, a quaternary phosphonium salt, and / or a phosphine compound is used. be able to. It is preferable that 0.1-25 mass% of this compound is added with respect to the sizing agent whole quantity except a solvent. 2-10 mass% is more preferable.

  The aliphatic epoxy compound (A) and the aromatic epoxy compound (B1) are selected from the above-mentioned tertiary amine compounds and / or tertiary amine salts, quaternary ammonium salts having a cation moiety, quaternary phosphonium salts and / or phosphine compounds. Adhesion is improved by applying a sizing agent in combination with at least one kind of compound to carbon fibers and heat-treating them under specific conditions. The mechanism is not certain, but first, a compound that promotes adhesion acts on oxygen-containing functional groups such as carboxyl groups and hydroxyl groups of the carbon fiber used in the present invention, and hydrogen contained in these functional groups. After the ions are extracted and anionized, the anionized functional group and the epoxy group contained in the aliphatic epoxy compound (A) or aromatic epoxy compound (B1) component are considered to undergo a nucleophilic reaction. Thereby, the strong coupling | bonding of the carbon group used by this invention and the epoxy group in a sizing agent is formed, and adhesiveness improves.

  Specific compounds that promote adhesion include N-benzylimidazole, 1,8-diazabicyclo [5,4,0] -7-undecene (DBU) and salts thereof, or 1,5-diazabicyclo [4, 3,0] -5-Nonene (DBN) and a salt thereof are preferable, and 1,8-diazabicyclo [5,4,0] -7-undecene (DBU) and a salt thereof, or 1,5- Diazabicyclo [4,3,0] -5-nonene (DBN) and its salts are preferred.

  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, SA881, manufactured by San Apro Corporation) and the like.

  In the present invention, tributylamine or N, N-dimethylbenzylamine, diisopropylethylamine, triisopropylamine, dibutylethanolamine, diethylethanolamine, triisopropanolamine, triethanolamine, N, N-diisopropylethylamine is preferable, In particular, triisopropylamine, dibutylethanolamine, diethylethanolamine, triisopropanolamine, and diisopropylethylamine are preferable.

  In addition to the above, examples of additives such as surfactants include polyalkylene oxides such as polyethylene oxide and polypropylene oxide, higher alcohols, polyhydric alcohols, alkylphenols, and polyalkylenes such as polyethylene oxide and polypropylene oxide in styrenated phenols. Nonionic surfactants such as compounds added with oxides and block copolymers of ethylene oxide and propylene oxide 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.

Next, the carbon fiber used in the present invention will be described.
In the present invention, examples of the carbon fiber 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.

  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 or more. 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.

  The carbon fiber used in the present invention preferably has a surface roughness (Ra) of 6.0 to 100 nm. More preferably, it is 15-80 nm, and 30-60 nm is suitable. The carbon fiber having a surface roughness (Ra) of 6.0 to 60 nm has a highly active edge portion on the surface, so that the interaction with the epoxy group of the sizing agent described above is improved, and the carbon fiber and the matrix resin. The interfacial adhesion can be improved. Moreover, since the carbon fiber whose surface roughness (Ra) is 6.0-100 nm has an unevenness | corrugation on the surface, it can improve interface adhesiveness by the anchor effect of a sizing agent, and is preferable.

The surface roughness (Ra) of the carbon fiber can be measured by using an atomic force microscope (AFM). For example, a carbon fiber cut to several millimeters in length is prepared, fixed on a substrate (silicon wafer) using a silver paste, and 3 atomic fibers at the center of each single fiber by an atomic force microscope (AFM). What is necessary is just to observe the image of a three-dimensional surface shape. As an atomic force microscope, a Dimension 3000 stage system or the like can be used in NanoScope IIIa manufactured by Digital Instruments and can be observed under the following observation conditions.
・ Scanning mode: Tapping mode ・ Probe: Silicon cantilever ・ Scanning range: 0.6μm × 0.6μm
・ Scanning speed: 0.3Hz
-Number of pixels: 512 × 512
・ Measurement environment: Room temperature, in air.
In addition, for each sample, for the images obtained by observing one single fiber from one point at a time, the roundness of the fiber cross section is approximated by a cubic surface, and the surface roughness of the carbon fiber is obtained for the entire obtained image. It is preferable to calculate (Ra), obtain the surface roughness (Ra) of the carbon fiber for five single fibers, and evaluate the average value.

  In the present invention, the total fineness of the carbon fibers is preferably 400 to 3000 tex. Moreover, the number of filaments of carbon fiber is preferably 1000 to 100,000, and more preferably 3000 to 50000.

  In the present invention, the single fiber diameter of the carbon fiber is preferably 4.5 to 7.5 μm. Since it is 7.5 micrometers or less, since a carbon fiber with high intensity | strength and elastic modulus can be obtained, it is used preferably. More preferably, it is 6 μm or less, and further preferably 5.5 μm or less. When the thickness is 4.5 μm or more, it is difficult to cause single fiber cutting in the process, and productivity is hardly lowered.

  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 0.07-0.25. When the surface oxygen concentration (O / C) is 0.05 or more, the oxygen-containing functional group on the surface of the carbon fiber can be secured and strong interface adhesion with the matrix resin can be obtained. Moreover, when the surface oxygen concentration (O / C) is 0.50 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 inside of the chamber was measured at 1 × 10 ⁻⁸ Torr. Measurement was performed at a photoelectron escape angle of 90 °. As a correction value for the peak accompanying charging during measurement, the binding energy value of the C _1s main peak (peak top) is adjusted to 284.6 eV. The C _1s peak area is obtained by drawing a straight base line in the range of 282 to 296 eV, and the O _1s peak area is obtained by drawing a straight base line in the range of 528 to 540 eV. The surface oxygen concentration O / C is represented by an atomic ratio calculated by dividing the ratio of the O _1s peak area by the sensitivity correction value unique to the apparatus. When ESCA-1600 manufactured by ULVAC-PHI Co., Ltd. is used as the X-ray photoelectron spectroscopy apparatus, the sensitivity correction value unique to the apparatus is 2.33.

  In the carbon fiber used in the present invention, the surface carboxyl group concentration (COOH / C) represented by the ratio of the number of carbon group (COOH) and carbon (C) atoms measured by chemical modification X-ray photoelectron spectroscopy. ) Is preferably in the range of 0.003 to 0.015. A more preferable range is 0.004 to 0.010. The surface hydroxyl group concentration (COH / C) represented by the ratio of the number of hydroxyl groups (OH) and carbon (C) on the surface of the carbon fiber measured by chemical modification X-ray photoelectron spectroscopy is 0.001 to 0. It is preferable to be within the range of .050. More preferably, it is the range of 0.010-0.040.

The surface carboxyl group concentration and hydroxyl group concentration of the carbon fiber are determined according to the following procedure by X-ray photoelectron spectroscopy.
The surface hydroxyl group concentration OH / C is determined by chemical modification X-ray photoelectron spectroscopy according to the following procedure. First, carbon fiber bundles from which the sizing agent and the like have been removed with a solvent are cut, spread and arranged on a platinum sample support, and placed in dry nitrogen gas containing 0.04 mol / liter of anhydrous trifluoride acetic acid gas. After 10 minutes of exposure at room temperature and chemical modification treatment, it was mounted on an X-ray photoelectron spectrometer with a photoelectron escape angle of 35 °, AlKα ₁ , ₂ was used as the X-ray source, and the inside of the sample chamber was 1 × 10 ⁻⁸ Torr. Keep the degree of vacuum. As correction of the peak accompanying charging during measurement, first, the binding energy value of the main peak of C _1s is adjusted to 284.6 eV. The C _1s peak area [C _1s ] is obtained by drawing a straight base line in the range of 282 to 296 eV, and the F _1s peak area [F _1s ] is obtained by drawing a straight base line in the range of 682 to 695 eV. Desired. Moreover, reaction rate r is calculated | required from _C1s peak division _| segmentation of the polyvinyl alcohol chemically modified simultaneously.

The surface hydroxyl group concentration (COH / C) is represented by a value calculated by the following equation.
COH / C = {[F _1s ] / (3k [C _1s ] −2 [F _1s ]) r} × 100 (%)
Note that k is the sensitivity correction value of the F _1s peak area with respect to the C _1s peak area unique to the apparatus, and when using the model SSX-100-206 manufactured by SSI of the United States, the sensitivity correction value specific to the apparatus is 3.919. .

The surface carboxyl group concentration COOH / C is determined by chemical modification X-ray photoelectron spectroscopy according to the following procedure. First, carbon fiber bundles from which the sizing agent and the like have been removed with a solvent are cut and spread and arranged on a platinum sample support, and 0.02 mol / liter of trifluorinated ethanol gas, 0.001 mol / liter of dicyclohexyl. The sample was exposed to air containing carbodiimide gas and 0.04 mol / liter pyridine gas at 60 ° C for 8 hours, chemically modified, mounted on an X-ray photoelectron spectrometer with a photoelectron escape angle of 35 °, and used as an X-ray source. Using AlKα ₁ and ₂ , the inside of the sample chamber is kept at a vacuum of 1 × 10 ⁻⁸ Torr. As correction of the peak accompanying charging during measurement, first, the binding energy value of the main peak of C _1s is adjusted to 284.6 eV. The C _1s peak area [C _1s ] is obtained by drawing a straight base line in the range of 282 to 296 eV, and the F _1s peak area [F _1s ] is obtained by drawing a straight base line in the range of 682 to 695 eV. Desired. Simultaneously, the reaction rate r is determined from the C _1s peak splitting of the polyacrylic acid chemically modified, and the residual rate m of the dicyclohexylcarbodiimide derivative is determined from the O _1s peak splitting.

The surface carboxyl group concentration COOH / C was represented by the value calculated by the following formula.
COOH / C = {[F _1s ] / (3k [C _1s ] − (2 + 13 m) [F _1s ]) r} × 100 (%)
Note that k is the sensitivity correction value of the F _1s peak area with respect to the C _1s peak area unique to the apparatus, and the sensitivity correction value specific to the apparatus when using the model SSX-100-206 manufactured by SSI of the United States is 3.919. is there.

The carbon fibers used in the present invention, it is preferred polar component of the surface free energy is of 8 mJ / ^{m 2} or more 50 mJ / ^{m 2} or less. When the polar component of the surface free energy is 8 mJ / m ² or more, the structure in which the components constituting the sizing layer are unevenly distributed is obtained as the aliphatic epoxy compound (A) comes closer to the carbon fiber surface, and the interfacial adhesiveness is obtained. Is preferable. When it is 50 mJ / m ² or less, since the impregnation property of the matrix resin between the carbon fibers becomes good, the use development is preferable when used as a composite material.

Polar component of the surface free energy of the carbon fiber surface is more preferably 15 mJ / ^{m 2} or more 45 mJ / ^{m 2} or less, and most preferably 25 mJ / ^{m 2} or more 40 mJ / ^{m 2} or less. The polar component of the surface free energy of the carbon fiber was calculated using an Owens approximation formula based on the contact angles measured by the Wilhelmi method in each liquid of water, ethylene glycol, and tricresole phosphate. Polar component of surface free energy.

The aliphatic epoxy compound (A) used in the present invention preferably has a surface free energy polar component of 9 mJ / m ² or more and 50 mJ / m ² or less. Further, the aromatic epoxy compound (B1) is a polar component of surface free energy 0 mJ / ^{m 2} or more, is preferably less than 9 mJ / ^{m 2.}
The polar component of the surface free energy of the aliphatic epoxy compound (A) and the aromatic epoxy compound (B1) is obtained by immersing the carbon fiber bundle in a solution consisting only of the aliphatic epoxy compound (A) or the aromatic epoxy compound (B1). After being pulled up and dried at 120 to 150 ° C. for 10 minutes, as described above, in each liquid of water, ethylene glycol, and tricresole phosphate, an approximate expression of Owens based on each contact angle measured by the Wilhelmi method Is the polar component of the surface free energy calculated using
In the present invention, the polar component E _CF of the surface free energy of the carbon fiber and the polar components E _A and E _B1 of the surface free energy of the aliphatic epoxy compound (A) and the aromatic epoxy compound (B1) are E _CF ≧ E _A > It is preferable to satisfy E _B1 .

Next, the manufacturing method of the PAN type carbon fiber preferably used for this invention is demonstrated.
As a spinning method for obtaining a carbon fiber precursor fiber, spinning methods such as wet, dry, and dry-wet can be used. From the viewpoint of easily obtaining high-strength carbon fibers, it is preferable to use a wet or dry wet spinning method. By using the dry and wet spinning method, it is preferable because a carbon fiber having high strength can be obtained. By using the wet spinning method, the surface roughness is increased and the interfacial adhesion between the carbon fiber and the matrix resin is further improved. preferable. The spinning method can be appropriately selected depending on the balance between the interfacial adhesion and the strength of the carbon fiber.

  As the spinning dope, a solution obtained by dissolving a homopolymer or copolymer of polyacrylonitrile in a solvent can be used. As the solvent, an organic solvent such as dimethyl sulfoxide, dimethylformamide, or dimethylacetamide, or an aqueous solution of an inorganic compound such as nitric acid, sodium rhodanate, zinc chloride, or sodium thiocyanate is used. Dimethyl sulfoxide and dimethylacetamide are suitable as the solvent.

  The above spinning solution is spun through a die, discharged in a spinning bath or in the air, and then coagulated in the spinning bath. As the spinning bath, an aqueous solution of a solvent used as a solvent for the spinning dope can be used. It is preferable to use a spinning solution containing the same solvent as the spinning solution, and a dimethyl sulfoxide aqueous solution and a dimethylacetamide aqueous solution are preferable. The fiber solidified in the spinning bath is washed with water and drawn to obtain a precursor fiber. The obtained precursor fiber is subjected to flameproofing treatment and carbonization treatment, and further subjected to graphitization treatment as necessary to obtain carbon 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.

  The obtained carbon fiber is usually subjected to an oxidation treatment in order to improve interfacial adhesion with the matrix resin, and oxygen-containing functional groups are introduced. 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. From the viewpoint of adhesion, a liquid phase electrolytic oxidation is performed in an alkaline electrolytic solution, and then a sizing agent is applied. Is more preferable.
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, an aqueous solution of ammonium carbonate and ammonium hydrogen carbonate, or an aqueous solution of tetraalkylammonium hydroxide exhibiting strong alkalinity is preferably used.

  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 less than 100 ° C., 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, it is preferable to wash and dry the carbon fiber after the electrolytic treatment. As a cleaning method, for example, a dip 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. Also, 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, so it is desirable to dry at the lowest possible temperature. Specifically, the drying temperature is preferably 250 ° C. or lower. More preferably, drying is performed at 210 ° C. or lower.

Next, the sizing agent-coated carbon fiber obtained by applying the sizing agent to the above-described carbon fiber will be described.
In the present invention, the sizing agent-coated carbon fiber means that the sizing agent is applied to continuous carbon fibers coated with a sizing agent, and carbon fibers processed into web-like, non-woven fabric, felt-like, matte-like fabrics. Means what
The sizing agent in the present invention includes at least the aromatic epoxy compound (B1) which is the aliphatic epoxy compound (A) and the aromatic compound (B), and may include other components.

  As a method for applying the sizing agent to the carbon fiber, the aromatic compound (B) containing at least the aliphatic epoxy compound (A) and the aromatic epoxy compound (B1) and other components were simultaneously dissolved or dispersed in a solvent. Sizing agent-containing liquid in which sizing agent-containing liquid is applied at once, each compound (A), (B1), (B) and other components are arbitrarily selected and dissolved or dispersed individually in a solvent A method of applying to carbon fiber in a plurality of times is preferably used. In the present invention, in order to set the composition of the surface of the carbon fiber coated with the sizing agent to a specific value, the sizing agent-containing liquid containing all the components of the sizing agent is applied to the carbon fiber in one step. Is more preferably used because of its effect and ease of processing.

  In the present invention, the sizing agent can be diluted with a solvent and used as a sizing solution. 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, an aqueous dispersion or aqueous solution emulsified with a surfactant is preferably used.

  In order of dissolution, a component containing at least the aromatic compound (B) is emulsified with a surfactant to prepare a water emulsion, and a solution containing at least the aliphatic epoxy compound (A) is mixed to form a sizing solution. It is preferable. At this time, when the aliphatic epoxy compound (A) is water-soluble, a method in which it is dissolved in water in advance to form an aqueous solution and mixed with a water emulsion containing at least the aromatic compound (B) is emulsified. It is preferably used from the viewpoint. In addition, it is preferable to use a water dispersant obtained by emulsifying the aliphatic epoxy compound (A), the aromatic compound (B) and other components with a surfactant from the viewpoint of long-term stability of the sizing agent.

  The concentration of the sizing agent in the sizing liquid needs to be adjusted as appropriate by adjusting the method of applying the sizing liquid and adjusting the amount of squeezing out the excess sizing liquid after the application, but usually 0.2% by mass to 20% by mass. The range of is preferable.

  Examples of means for applying (applying) the sizing agent to the carbon fiber include a method of immersing the carbon fiber or a fabric processed with the carbon fiber in a sizing liquid through a roller, and a carbon fiber or fabric on a roller to which the sizing liquid is adhered. There are a method of contacting, a method of spraying carbon fiber or fabric on a sizing solution in a mist form. 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 active component of the sizing agent attached to the carbon fiber or the fabric processed from the carbon fiber uniformly adheres 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.

  The liquid temperature of the sizing liquid is preferably in the range of 10 to 50 ° C. in order to suppress fluctuations in the concentration of the sizing agent due to solvent evaporation. Further, after applying the sizing liquid, the amount of sizing agent attached and the carbon fiber can be uniformly applied by adjusting the amount of squeezing out excess sizing liquid.

  In this invention, after apply | coating a sizing agent to the fabric which processed the carbon fiber or carbon fiber, it is preferable to heat-process for 30 to 600 second in the temperature range of 160-260 degreeC. The heat treatment conditions are preferably in a temperature range of 170 to 250 ° C. for 30 to 500 seconds, and more preferably in a temperature range of 180 to 240 ° C. for 30 to 300 seconds. When the heat treatment condition is 160 ° C. or higher and / or 30 seconds or longer, the interaction between the epoxy compound of the sizing agent and the oxygen-containing functional group on the surface of the carbon fiber is promoted, and the interfacial adhesion between the carbon fiber and the matrix resin is promoted. This is preferable because of sufficient properties. On the other hand, when the heat treatment condition is 260 ° C. or less and / or 600 seconds or less, the decomposition and volatilization of the sizing agent can be suppressed, the interaction with the carbon fiber is promoted, and the interfacial adhesion between the carbon fiber and the matrix resin is sufficient. This is preferable.

  The heat treatment can also be performed by microwave irradiation and / or infrared irradiation. When carbon fiber or fabric coated with a sizing agent by microwave irradiation and / or infrared irradiation is heat-treated, the microwave penetrates into the carbon fiber and is absorbed, so that the carbon fiber that is the object to be heated in a short time Can be heated to the desired temperature. In addition, since the inside of the carbon fiber can be quickly heated by microwave irradiation and / or infrared irradiation, the temperature difference between the inside and outside of the carbon fiber bundle can be reduced, and the adhesion unevenness of the sizing agent can be reduced. It becomes possible to do.

The sizing agent-coated carbon fiber according to the present invention has a C _1s inner shell spectrum (a) measured by X-ray photoelectron spectroscopy at a photoelectron escape angle of 15 ° using AlKα ₁ and ₂ with the sizing agent surface as the X-ray source. The height (cps) of the component of the bond energy (284.6 eV) attributed to CHx, C—C, C = C, and (b) of the component of the bond energy (286.1 eV) attributed to C—O The ratio (a) / (b) to the height (cps) is 0.50 to 0.90. The ratio (a) / (b) is preferably 0.55 or more, more preferably 0.57 or more. The ratio (a) / (b) is preferably 0.80 or less, more preferably 0.74 or less. A large (a) / (b) indicates that there are many aromatic-derived compounds and few aliphatic-derived compounds in the vicinity of the sizing agent surface. Therefore, in the present invention, when (a) / (b) falls within a specific range, the adhesion between the carbon fiber and the sizing agent is excellent, and the interaction between the sizing agent and the matrix resin is increased. . As a result, the interfacial adhesion between the carbon fiber and the matrix resin is excellent, and the properties of the resulting carbon fiber reinforced composite material are improved. In addition, when the carbon fiber is used, even when a highly hygroscopic matrix resin is used, the obtained carbon fiber reinforced composite material is found to have good mechanical properties under wet conditions. is there.

  X-ray photoelectron spectroscopy is an analysis in which the sizing agent-coated carbon fiber of a sample is irradiated with X-rays in an ultra-high vacuum, and the kinetic energy of photoelectrons emitted from the surface of the carbon fiber is measured with an apparatus called an energy analyzer. It is a technique. By examining the kinetic energy of the photoelectrons emitted from the carbon fiber surface of the sample, the binding energy converted from the energy value of the X-rays incident on the carbon fiber of the sample is uniquely determined. From the binding energy and the photoelectron intensity The type and concentration of elements present on the outermost surface (˜nm) of the sample and the chemical state thereof can be analyzed.

In the present invention, the peak ratio of (a) and (b) on the surface of the sizing agent-coated carbon fiber is determined by X-ray photoelectron spectroscopy according to the following procedure. The carbon fiber coated with the sizing agent is cut to 20 mm, spread and arranged on a copper sample support, and AlKα ₁ and ₂ are used as an X-ray source, and the sample chamber is kept at 1 × 10 ⁻⁸ Torr. Measurement is performed. As correction of the peak accompanying charging during measurement, first, the binding energy value of the main peak of C _1s is adjusted to 286.1 eV. At this time, the peak area of C _1s is obtained by drawing a straight baseline in the range of 282 to 296 eV. Further, a linear base line of 282 to 296 eV obtained by calculating the area at the C _1s peak is defined as the origin (zero point) of the photoelectron intensity, and (b) the peak of the binding energy 286.1 eV attributed to the CO component is obtained. The height (cps: photoelectron intensity per unit time) and the height (cps) of the component having a binding energy of 284.6 eV attributed to (a) CHx, C—C, C = C are obtained, and (a) / ( b) is calculated.

The sizing agent-coated carbon fiber according to the present invention has a C1s inner shell spectrum (a) of the sizing agent surface coated on the carbon fiber, measured at a photoelectron escape angle of 55 ° by X-ray photoelectron spectroscopy using 400 eV X-rays. The height (cps) of the component of the bond energy (284.6 eV) attributed to CHx, C—C, C = C, and (b) of the component of the bond energy (286.1 eV) attributed to C—O It is preferable that the values of (I) and (II) obtained from the ratio (a) / (b) to the height (cps) satisfy the relationship of (III).
(I) The value of (a) / (b) on the surface of the sizing agent-coated carbon fiber before sonication (II) The sizing agent-coated carbon fiber is sonicated in an acetone solvent to reduce the sizing agent adhesion amount. The value of (a) / (b) (III) 0.50 ≦ (I) ≦ 0.90 and 0.60 <(II) on the surface of the sizing agent-coated carbon fiber washed to 0.09 to 0.20% by mass. ) / (I) <1.0

The fact that (I), which is the (a) / (b) value on the surface of the sizing agent-coated carbon fiber before ultrasonic treatment, falls within the above range means that there are many aromatic-derived compounds on the surface of the sizing agent. It shows that there are few compounds. The (a) / (b) value (I) before sonication is preferably 0.55 or more, more preferably 0.57 or more. Moreover, (I) which is (a) / (b) value before ultrasonic treatment is preferably 0.80 or less, more preferably 0.74 or less.
The fact that (II) / (I), which is the ratio of (a) / (b) values on the sizing agent-coated carbon fiber surface before and after the ultrasonic treatment, falls within the above range, indicates that the inner layer of the sizing agent compared to the sizing agent surface. Indicates that the ratio of the aliphatic compound is large. (II) / (I) is preferably 0.65 or more. Further, (II) / (I) is preferably 0.85 or less.
When the values of (I) and (II) satisfy the relationship of (III), a carbon fiber reinforced material having excellent physical properties with excellent adhesion to the matrix resin and high interaction with the matrix resin can be obtained. In addition, the ultrasonic treatment described here means that 2 g of sizing agent-coated carbon fiber is immersed in 50 ml of acetone and ultrasonic cleaning is performed for 30 minutes three times, followed by immersion in 50 ml of methanol and ultrasonic cleaning 30. It means the process of performing a minute once and drying.

  In this invention, it is preferable that the adhesion amount of the sizing agent to carbon fiber is the range of 0.1-10.0 mass parts with respect to 100 mass parts of carbon fibers, More preferably, 0.2-3. The range is 0 part by mass. When the sizing agent adhesion amount is 0.1 parts by mass or more, when the carbon fiber coated with the sizing agent is mixed with the matrix resin, it can withstand friction caused by a metal guide or the like passing through, and fluff generation can be suppressed. Excellent quality such as smoothness of carbon fiber sheet. On the other hand, when the adhesion amount of the sizing agent is 10.0 parts by mass or less, the carbon resin obtained by impregnating the matrix resin inside the carbon fiber without being inhibited by the sizing agent film around the carbon fiber coated with the sizing agent is obtained. It is preferable because void generation in the fiber reinforced composite material is suppressed, the quality is excellent, and the mechanical properties are excellent at the same time.

  The amount of the sizing agent attached to the carbon fiber was measured by collecting about 2 ± 0.5 g of the carbon fiber coated with the sizing agent and performing the heat treatment at 450 ° C. for 15 minutes in a nitrogen atmosphere before and after the heat treatment. The amount of mass change per 100 parts by mass of the carbon fiber coated with the sizing agent or the fabric processed with the carbon fiber, which is obtained by measuring the change in mass, is defined as the adhering amount (part by mass) of the sizing agent.

  In the present invention, the epoxy equivalent of the sizing agent applied to the carbon fiber is 350 to 550 g / eq. It is preferable that 550 g / eq. The following is preferable because the interfacial adhesion between the carbon fiber coated with the sizing agent and the matrix resin is improved, and the physical properties of the carbon fiber reinforced composite material are improved. 350 g / eq. The above is sufficient from the viewpoint of adhesiveness.

  The epoxy equivalent of the carbon fiber coated with the sizing agent in the present invention is that the carbon fiber coated with the sizing agent is immersed in a solvent typified by N, N-dimethylformamide and eluted from the fiber by ultrasonic cleaning. After that, the epoxy group can be opened with hydrochloric acid, and it can be determined by acid-base titration. Epoxy equivalent is 360 g / eq. The above is preferable, and 380 g / eq. The above is more preferable. In addition, 530 g / eq. The following is preferable, and 500 g / eq. The following is more preferable. In addition, the epoxy equivalent of the sizing agent applied to the carbon fiber can be controlled by the epoxy equivalent of the sizing agent used for application and the heat history in drying after application.

  In this invention, the adhesion amount of the aliphatic epoxy compound (A) to the cloth which processed carbon fiber or carbon fiber shall be the range of 0.05-5.0 mass parts with respect to 100 mass parts of carbon fibers. Is more preferable, and the range of 0.2 to 2.0 parts by mass is more preferable. More preferably, it is 0.3-1.0 mass part. When the adhesion amount of the aliphatic epoxy compound (A) is 0.05 parts by mass or more, the interfacial adhesion between the carbon fiber and the matrix resin in which the sizing agent is applied to the carbon fiber surface with the aliphatic epoxy compound (A) is improved. Therefore, it is preferable.

  In the present invention, the thickness of the sizing agent layer applied to the carbon fiber and dried is preferably within a range of 2.0 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 furthermore, excellent high-order workability can be obtained.

  In the present invention, when the carbon fiber coated with the sizing agent is eluted with an acetonitrile / chloroform mixed solvent, the proportion of the aliphatic epoxy compound (A) eluted is 100 parts by mass of the carbon fiber coated with the sizing agent. The amount is preferably 2.0 parts by mass or less, and more preferably 0.3 parts by mass or less. In particular, when the elution amount of the aliphatic epoxy compound (A) is 0.3 parts by mass or less, the moisture content on the carbon fiber surface decreases when the carbon fiber coated with the sizing agent of the present invention is mixed with the matrix resin. It is preferable because the interaction with the matrix resin becomes strong. From this viewpoint, the proportion of the eluted aliphatic epoxy compound (A) is more preferably 0.1 parts by mass or less, and 0.05 parts by mass or less with respect to 100 parts by mass of the carbon fiber to which the sizing agent is applied. Is more preferable.

The proportion of the eluted aliphatic epoxy compound (A) was determined by immersing a carbon fiber test piece coated with a sizing agent in an acetonitrile / chloroform mixed solution (volume ratio 9/1) and performing ultrasonic cleaning for 20 minutes. The eluate obtained by eluting the sizing agent into an acetonitrile / chloroform mixture can be analyzed under the following conditions using liquid chromatography.
・ Analytical column: Chromolis Performance RP-18e (4.6 × 100 mm)
-Mobile phase: Water / acetonitrile was used, and after 7 minutes from the start of analysis, water / acetonitrile = 60% / 40% to acetonitrile 100%, then 100% acetonitrile was retained for 12 minutes, and then 12.1 minutes By the time, water / acetonitrile = 60% / 40%, and water / acetonitrile = 60% / 40% was maintained until 17 minutes.
-Flow rate: 2.5 mL / min-Column temperature: 45 ° C
Detector: Evaporative light scattering detector (ELSD)
-Detector temperature: 60 ° C

  In this invention, it is preferable that the moisture content of sizing agent application | coating carbon fiber is 0.010-0.030 mass%. When the moisture content of the sizing agent-coated carbon fiber is 0.030% by mass or less, high mechanical properties of the carbon fiber-reinforced composite material can be maintained even under wet conditions. The moisture content of the sizing agent-coated carbon fiber is preferably 0.024% by mass or less, more preferably 0.022% by mass or less, and the lower limit of the moisture content is 0.010% by mass or more. This is preferable because the uniform application property of the sizing agent applied to the carbon fiber is improved. 0.015 mass% or more is more preferable. The moisture content of the sizing agent-coated carbon fiber can be measured by weighing about 2 g of the sizing agent-coated carbon fiber and using a moisture meter such as KF-100 (capacity method Karl Fischer moisture meter) manufactured by Mitsubishi Chemical Analytech. The heating temperature at the time of measurement was 150 ° C.

Then, the manufacturing method concerning the molding material and carbon fiber reinforced composite material concerning this invention is demonstrated. The molding material concerning this invention is suitably manufactured by the following two methods.
The first method is
A processing step of processing carbon fiber into a web-like, non-woven, felt-like, or mat-like fabric;
For 100 parts by mass of the dough obtained in the processing step, 35 to 65% by mass of the aliphatic epoxy compound (A) and 35 to 60% by mass of the aromatic compound (B) with respect to the total amount of the sizing agent excluding the solvent; An application step of applying 0.1 to 10 parts by mass of a sizing agent containing at least
A compounding step in which 20 to 99% by mass of the matrix resin is applied to 1 to 80% by mass of the dough to which the sizing agent is applied in the applying step.

The second method is
A sizing agent containing at least 35 to 65% by mass of an aliphatic epoxy compound (A) and 35 to 60% by mass of an aromatic compound (B) with respect to 100 parts by mass of carbon fiber, based on the total amount of the sizing agent excluding the solvent An application step of applying 0.1 to 10 parts by mass to obtain a sizing agent-coated carbon fiber;
A cutting step of cutting the sizing agent-coated carbon fiber obtained in the coating step into 1 to 50 mm;
It includes at least a compounding step in which 1 to 80% by mass of sizing agent-coated carbon fibers cut in the cutting step and 20 to 99% by mass of a matrix resin are mixed and compounded.

  First, a first method, which is a method for producing a molding material in which carbon fibers are monofilamentous and substantially two-dimensionally oriented, will be described.

  In the first method, the carbon fiber is processed into a web-like, non-woven fabric, felt-like, or mat-like fabric (processing step). A web-like carbon fiber fabric can be manufactured by dispersing and processing carbon fiber bundles. As long as the carbon fiber bundle is the above-described carbon fiber, either a continuous carbon fiber or a discontinuous carbon fiber may be used, but in order to achieve a better dispersion state, Discontinuous carbon fibers are preferred, and chopped carbon fibers are more preferred.

  The dispersion of the carbon fiber can be performed by either a wet method or a dry method. The wet method is a method in which carbon fiber bundles are dispersed and made in water, and the dry method is a method in which carbon fiber bundles are dispersed in air.

  In the case of a wet method, a sheet-like carbon fiber fabric can be obtained by making a slurry obtained by dispersing a carbon fiber bundle in water.

  As water (dispersion liquid) for dispersing the carbon fiber bundle, water such as distilled water and purified water can be used in addition to normal tap water. A surfactant may be mixed in the water as necessary. Surfactants are classified into a cation type, an anion type, a nonionic type, and an amphoteric type. Of these, nonionic surfactants are preferably used, and polyoxyethylene lauryl ether is more preferably used. . The concentration of the surfactant when mixing the surfactant with water is usually 0.0001% by mass or more and 0.1% by mass or less, preferably 0.0005% by mass or more and 0.05% by mass or less.

  The amount of the carbon fiber bundle added to water (dispersion) can be adjusted in the range of usually 0.1 g or more and 10 g or less, preferably 0.3 g or more and 5 g or less as the amount of water (dispersion) 1 l. By setting it as the said range, the carbon fiber bundle can disperse | distribute efficiently to water (dispersion liquid), and the slurry disperse | distributed uniformly can be obtained in a short time. When the carbon fiber bundle is dispersed in water (dispersion), stirring is performed as necessary.

  The slurry refers to a suspension in which solid particles are dispersed. In the present invention, an aqueous slurry is preferable. The solid content concentration (mass content of carbon fibers in the slurry) in the slurry is preferably 0.01% by mass or more and 1% by mass or less, and preferably 0.03% by mass or more and 0.5% by mass or less. More preferred. Papermaking can be performed efficiently by being in the above range.

  The slurry can be made by sucking water from the slurry. Slurry papermaking can be performed according to a so-called papermaking method. For example, the slurry can be poured into a tank having a papermaking surface at the bottom and capable of sucking water from the bottom, and the water can be sucked. As said tank, the Kumagaya Riki Kogyo Co., Ltd. make, No. 2553-I (trade name), and a tank provided with a mesh conveyor having a papermaking surface with a width of 200 mm at the bottom. In this way, a carbon fiber sheet is obtained.

  In the case of the dry method, the carbon fiber bundle can be dispersed in the gas phase to obtain a carbon fiber sheet. That is, it is possible to obtain a carbon fiber sheet by dispersing the carbon fiber bundles in the gas phase and depositing the dispersed carbon fiber bundles.

  Dispersion of carbon fiber bundles in the gas phase is performed by opening the carbon fiber bundles in a non-contact manner and depositing the opened carbon fiber bundles (non-contact method), applying an air flow to the carbon fiber bundles. The carbon fiber bundles that are opened and deposited, and the carbon fiber bundles are deposited (method using an air flow). The dispersion of the carbon fiber bundles in the gas phase is performed by opening the carbon fiber bundles in a contact manner. There are three types of methods (contact method) in which the carbon fiber bundles deposited are deposited.

  The non-contact method is a method of opening a carbon fiber bundle without bringing a solid or a fiber opening device into contact therewith. For example, a method of spraying a gas such as air or an inert gas onto the reinforcing fiber bundle, particularly a method of pressurizing and spraying air advantageous in terms of cost is preferable.

  In the method using an air flow, the conditions for applying the air flow to the carbon fiber bundle are not particularly limited. As an example, pressurized air (usually an air flow that applies a pressure of 0.1 MPa to 10 MPa, preferably 0.5 MPa to 5 MPa) is applied until the carbon fiber bundle is opened. In the method using an air flow, an apparatus that can be used is not particularly limited, and examples thereof include a container that includes an air tube and is capable of air suction and can contain a carbon fiber bundle. By using such a container, the opening and deposition of the carbon fiber bundle can be performed in one container.

  The contact method is a method in which a carbon fiber bundle is physically contacted with a solid or an opening device to open the fiber. Examples of the contact method include carding, needle punching, and roller opening. Of these, carding and needle punching are preferable, and carding is more preferable. The conditions for carrying out the contact method are not particularly limited, and conditions for opening the carbon fiber bundle can be appropriately determined.

Sheet having a basis weight of the carbon fiber fabric was prepared as described above is preferably 10 to 500 g / m ^2, and more preferably 50 to 300 g / m ^2. 10 g / m can cause a risk of failure is less than ² handling properties such as tear of the base material, when it exceeds 500 g / m ^2, and it takes a long time to dry the substrate by a wet method, a dry method Sheet May become thick, and handling may be difficult in subsequent processes.

  After the processing step, 35 to 65% by mass of the aliphatic epoxy compound (A) and the aromatic compound (B) with respect to 100 parts by mass of the carbon fiber sheet that is the obtained dough, based on the total amount of the sizing agent excluding the solvent. 0.1 to 10 parts by mass of a sizing agent containing at least 35 to 60% by mass is applied (applying step). The sizing agent comprising the aliphatic epoxy compound (A) and the aromatic compound (B) is also referred to as a “binder” in the first method of the present invention, and improves the handleability of the carbon fiber in the process. It is important for the viewpoint and the interfacial adhesion between the carbon fiber and the matrix resin. When the sizing agent is 0.1 parts by mass or more, the handleability of the carbon fiber sheet is improved, and the production efficiency of the molding material is increased. Moreover, the interface adhesiveness of carbon fiber and matrix resin becomes high at 10 mass parts or less.

  The sizing agent is preferably applied to the carbon fiber sheet by using an aqueous solution, emulsion or suspension containing the sizing agent. The aqueous solution means a solution in which the aliphatic epoxy compound (A) and the aromatic compound (B) are almost completely dissolved in water. An emulsion means a state in which a liquid containing an aliphatic epoxy compound (A) and an aromatic compound (B) is dispersed in a liquid serving as a dispersion medium by forming fine particles. Suspension means a state where solid aliphatic epoxy compound (A) and aromatic compound (B) are suspended in water. The component particle sizes in the liquid are in the order of aqueous solution <emulsion <suspension. The method for applying the sizing agent to the carbon fiber sheet is not particularly limited. For example, a method of immersing the carbon fiber sheet in an aqueous sizing agent solution, emulsion or suspension, or a method of showering the aqueous sizing agent solution, emulsion or suspension on the carbon fiber sheet. Etc. After the application, it is preferable to remove the excess aqueous solution, emulsion, or suspension by, for example, a method of removing by suction or a method of absorbing into an absorbent material such as absorbent paper.

  In the application step, the carbon fiber sheet is preferably heated after application of the sizing agent. Thereby, the water | moisture content contained in the carbon fiber sheet after a sizing agent was provided is removed, the time which a next process requires can be shortened, and a molding material can be obtained in a short time. The heating temperature can be appropriately set and is preferably 100 ° C. or higher and 300 ° C. or lower, and more preferably 120 ° C. or higher and 250 ° C. or lower.

  In order to produce a large number of carbon fiber sheets to which a sizing agent has been applied in a short time, it is preferable to perform take-up. At that time, it is preferable to pull the carbon fiber sheet in a state where the tensile strength is 1 N / cm or more so that wrinkles and sagging do not occur. The tensile strength is more preferably 3 N / cm or more, and further preferably 5 N / cm or more. The tensile strength that can be applied to the carbon fiber sheet can be controlled by adjusting the type and application amount of the sizing agent, and the tensile strength can be increased by increasing the application amount. Moreover, when the applied tensile strength is less than 1 N / cm, the carbon fiber sheet is easily broken, and the tensile strength is preferably 1 N / cm or more from the viewpoint of the handleability of the carbon fiber sheet. The upper limit of the tensile strength is not particularly limited, but if it is 100 N / cm, the handleability of the carbon fiber sheet is sufficiently satisfactory.

  In the compounding step, the carbon fiber sheet provided with the sizing agent obtained in the applying step is impregnated with a matrix resin, and the carbon fiber sheet and the thermoplastic resin are combined to obtain a molding material.

  In the first method, the carbon fiber, the sizing agent, and the thermoplastic resin are contained in the molding material in an amount of 1 to 70 mass% for the carbon fiber, 0.1 to 10 mass% for the sizing agent, and 20 to 98 mass% for the matrix resin. 9% by mass. By setting it as this range, the molding material which can exhibit the reinforcement of carbon fiber efficiently can be obtained easily. More preferably, the carbon fiber is 10 to 60% by mass, the sizing agent is 0.5 to 10% by mass, and the matrix resin is 30 to 89.5% by mass. More preferably, the carbon fiber is 20 to 60% by mass, the sizing agent is 1 to 8% by mass, and the matrix resin is 32 to 79% by mass.

  In the first method, when a thermoplastic resin is used as the matrix resin, the composite of the thermoplastic resin and the carbon fiber sheet to which the sizing agent is applied is performed by bringing the thermoplastic resin into contact with the carbon fiber sheet. It can be carried out. The form of the thermoplastic resin in this case is not particularly limited, but is preferably at least one form selected from, for example, a fabric, a nonwoven fabric, and a film. Although the contact method is not particularly limited, a method of preparing two thermoplastic resin fabrics, non-woven fabrics, or films and arranging them on both upper and lower surfaces of a carbon fiber sheet provided with a sizing agent is exemplified.

  In the first method, the composite of the thermoplastic resin and the carbon fiber sheet provided with the sizing agent is preferably performed by pressurization and / or heating, and both pressurization and heating are performed simultaneously. Is more preferable. The pressurization condition is preferably 0.01 MPa or more and 10 MPa or less, and more preferably 0.05 MPa or more and 5 MPa or less. The heating condition is preferably a temperature at which the thermoplastic resin to be used can be melted or flowed, and is preferably 50 ° C. or higher and 400 ° C. or lower, more preferably 80 ° C. or higher and 350 ° C. or lower in the temperature range. The pressurization and / or heating can be performed in a state where the thermoplastic resin is in contact with the carbon fiber sheet to which the sizing agent is applied. For example, two thermoplastic resin fabrics, non-woven fabrics or films are prepared, placed on both upper and lower surfaces of a carbon fiber sheet provided with a sizing agent, and heated and / or heated from both sides (a method of sandwiching with a double belt press device) Etc.) method.

  In the molding material of the present invention produced by the first method, the carbon fibers are monofilamentous and have a substantially two-dimensional orientation. “Two-dimensional orientation” means that the average value of the two-dimensional orientation angle formed by the carbon fiber single fiber constituting the molding material and the other closest carbon fiber single fiber is 10 to 80 °. means. The two-dimensional orientation angle can be measured by observing the molding material with an optical microscope or an electron microscope. In the molding material, the two-dimensional orientation angle of 400 carbon fibers is measured and an average value is obtained. “Substantially” the carbon fibers are in a two-dimensional orientation means that the number of carbon fibers is usually 70% or more, preferably 95% or more, more preferably all of the 400 carbon fibers are in a two-dimensional orientation. Means that.

  Subsequently, a second method, which is a method for producing a molding material in which carbon fibers are bundled and substantially two-dimensionally oriented, will be described. The second method comprises at least a coating process, a cutting process, and a compounding process.

  In an application | coating process, 35-65 mass% of aliphatic epoxy compounds (A) and 35-60 mass% of aromatic compounds (B) with respect to 100 mass parts of carbon fibers with respect to the sizing agent whole quantity which removed the solvent at least. A sizing agent-coated carbon fiber is obtained by adhering 0.1 to 10 parts by mass of the sizing agent. As described above, the method of applying the sizing agent to the carbon fiber includes the method of immersing the carbon fiber in the sizing liquid through the roller, the method of contacting the carbon fiber with the roller to which the sizing liquid is attached, and the sizing liquid being atomized. A method of spraying on carbon fiber can be used.

  In a cutting process, the sizing agent application | coating carbon fiber obtained at the application | coating process is cut into 1-50 mm. The length of the carbon fiber is preferably 1 to 50 mm. This is because if it is less than 1 mm, it may be difficult to efficiently exhibit reinforcement and hardening by carbon fibers, and if it exceeds 50 mm, it may be difficult to maintain good dispersion. The cutting can be performed by a known method such as a guillotine cutter or a rotary cutter such as a roving cutter.

  In the compounding step, the sizing agent-coated carbon fiber and the matrix resin cut in the cutting step are mixed so that the sizing agent-coated carbon fiber is 1 to 80% by mass and the matrix resin is 20 to 99% by mass to be compounded. To do. The blending ratio between the sizing agent-coated carbon fiber and the matrix resin is preferably 1 to 80% by mass for the sizing agent-coated carbon fiber and 20 to 99% by mass for the matrix resin, and more preferably, the sizing agent-coated carbon fiber is 10-70 mass%, matrix resin is 30-90 mass%, More preferably, sizing agent application | coating carbon fiber is 20-60 mass%, and matrix resin is 40-80 mass%.

  In the molding material of the present invention produced by the second method, the carbon fibers are bundled and have a substantially two-dimensional orientation. “Two-dimensional orientation” has the same meaning as in the first method.

  In the first method and the second method, a thermosetting resin or a thermoplastic resin is used as the matrix resin used in the compounding step. In particular, in the first method, a thermoplastic resin is preferably used from the viewpoint of moldability.

  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 these, radical polymerization resins such as unsaturated polyester resins are preferably used.

  Unsaturated polyester resins can be obtained from unsaturated polybasic acids or optionally unsaturated polybasic acids including saturated polybasic acids and polyhydric alcohols. Examples of the unsaturated polybasic acid include maleic acid, maleic anhydride, fumaric acid, itaconic acid, itaconic anhydride, mesaconic acid, citraconic acid, citraconic anhydride, chloromaleic acid, pyromellitic acid and the like (di) Examples include alkyl esters. These unsaturated polybasic acids can be used individually by 1 type, or can also be used in combination of 2 or more type. Examples of the saturated polybasic acid that replaces part of the unsaturated polybasic acid include phthalic acid, phthalic anhydride, isophthalic acid, terephthalic acid, hexahydrophthalic anhydride, azelaic acid, adipic acid, sebacic acid, and het acid Etc. These saturated polybasic acids can be used individually by 1 type, or can also be used in combination of 2 or more type.

  Examples of the polyhydric alcohol include ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, trimethylene glycol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, and 1,2-pentane. Propylene oxide addition of diol, 1,6-hexanediol, cyclohexanediol, neopentyl glycol, 2,2,4-trimethyl-1,3-pentanediol, glycerin monoallyl ale, bisphenol A, hydrogenated bisphenol A, bisphenol A , Bisphenol A ethylene oxide adduct, glycidylated bisphenol A, glycidylated bisphenol F, glycerin, trimethylolpropane, pentaerythritol, ethylene oxide, pro Ren'okishido, can be mentioned epichlorohydrin. These polyhydric alcohols may be used alone or in combination of two or more.

  For the purpose of reducing the weight of the molding material, a thermoplastic resin can be included in the thermosetting resin. A thermoplastic resin composition that is solid at room temperature is preferred for weight reduction. In particular, a composition comprising any one of a saturated polyester, a polyvinyl compound, a polyacetate or a poly (meth) acrylate, or a combination thereof can be preferably used. Among them, the poly (meth) acrylate is easy to handle and Since it is inexpensive, it can be most preferably used.

  The blending amount of the thermoplastic resin in the thermosetting resin is preferably 10% by mass or more, particularly preferably 20% by mass or more, and preferably 60% by mass or less, particularly preferably 40% by mass or less. This is because if the amount of the thermoplastic resin exceeds 60% by mass, the strength when shaped into a carbon fiber reinforced composite material is lowered.

  The thermosetting resin that can be used in the present invention includes the above-mentioned thermoplastic resin, a curing agent (polymerization initiator), a curing catalyst, a release agent, a thickener, a colorant, and other fillers. It is possible to add other additives. For example, azo compounds and peroxides as the curing agent, chain transfer agents such as mercaptans as the curing catalyst, and higher fatty acids such as stearic acid or their metal salts as the release agent are increased. An alkaline earth metal oxide or the like can be used as the sticking agent, and an appropriate amount of an inorganic pigment or toner can be used as the coloring agent.

  When using a thermoplastic resin, for example, “polyester resins such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polytrimethylene terephthalate (PTT), polyethylene naphthalate (PEN), liquid crystal polyester; polyethylene (PE ), Polypropylene (PP), polybutylene, acid-modified polyethylene (m-PE), acid-modified polypropylene (m-PP), acid-modified polybutylene, and other polyolefin resins; polyoxymethylene (POM), polyamide (PA), polyphenylene sulfide Polyarylene sulfide resins such as (PPS); polyketone (PK), polyetherketone (PEK), polyetheretherketone (PEEK), polyetherketoneketone (PEKK), polyethernitrile (PEN); fluororesin such as polytetrafluoroethylene; crystalline resin such as liquid crystal polymer (LCP), polystyrene 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, poly Preferably used are at least one selected from a copolymer, a modified body, and the like such as stealth elastomer, polyamide elastomer, polybutadiene elastomer, polyisoprene elastomer, various thermoplastic elastomers such as fluororesin and acrylonitrile elastomer. It is done. In addition, as a thermoplastic resin, you may use multiple types of these thermoplastic resins in the range which does not impair the objective of this invention.

  Among the above thermoplastic resins, at least selected from the group consisting of polyarylene sulfide resins, polyether ether ketone resins, polyphenylene ether resins, polyoxymethylene resins, polyester resins, polycarbonate resins, polystyrene resins and polyolefin resins. One type of thermoplastic resin is preferable because the interaction with the aromatic compound (B) is large and the interaction between the sizing agent and the thermoplastic resin becomes strong, so that a strong interface can be formed.

  The thermoplastic resin used in the present invention is preferably a polyarylene sulfide resin or a polyether ether ketone resin from the viewpoint of heat resistance. From the viewpoint of dimensional stability, polyphenylene ether resin is preferable. From the viewpoint of friction and wear characteristics, polyoxymethylene resin is preferred. From the viewpoint of strength, a polyamide resin is preferable. From the viewpoint of surface appearance, an amorphous resin such as polycarbonate or polystyrene resin is preferable. From the viewpoint of lightness, polyolefin resin is preferable.

  More preferably, it is at least one selected from polyarylene sulfide resin, polycarbonate resin and polyolefin resin, or polyamide. Polyarylene sulfide resins are particularly preferable from the viewpoint of heat resistance, and polyolefin resins are particularly preferable from the viewpoint of light weight.

  In addition, when a highly water-absorbing resin typified by polyamide or the like is used, it is preferable because the physical properties are maintained even during water absorption due to the effect of lowering the moisture content by the aromatic compound (B) on the carbon fiber surface. In particular, a polyamide resin is preferable because of its high strength.

In the present invention, the interaction with the sizing agent when the preferred thermoplastic resin is used will be described.
In the present invention, the remaining epoxy group, hydroxyl group, amide group, imide group, urethane group, urea group, sulfonyl group, or sulfo group that does not participate in the interaction with the carbon fiber contained in the sizing agent is the main component of the thermoplastic resin. Ether groups, ester groups, sulfide groups, amide groups in the chain, acid anhydride groups in the side chain, cyano groups, and functional groups such as terminal hydroxyl groups, carboxyl groups, amino groups, and covalent bonds and hydrogen bonds It is considered that an interaction is formed and interfacial adhesion is improved. In particular, it is considered that the functional group of the aromatic compound (B) present in a large amount in the outer layer of the sizing agent forms an interaction with the thermoplastic resin and enhances the interfacial adhesion.

  When polyarylene sulfide resin is used as a matrix resin, interaction such as covalent bond between thiol group or carboxyl group at the terminal of polyarylene sulfide resin and epoxy group of sizing agent, sulfide group in main chain and sizing agent In particular, a strong interface can be formed by hydrogen bonding with an epoxy group, a hydroxyl group, an amide group, an imide group, a urethane group, a urea group, a sulfonyl group, or a sulfo group contained in the aromatic compound (B). It is done. In particular, it is considered that high adhesiveness can be obtained by the interaction between the aromatic ring in the thermoplastic resin and the aromatic compound (B) of the sizing agent.

  In addition, when a polyamide resin is used as a matrix resin, an interaction such as a covalent bond between a carboxyl group or amino group at the end of the polyamide resin and an epoxy group contained in the sizing agent, an amide group in the main chain, and a sizing agent In particular, a strong interface can be formed by hydrogen bonding with an epoxy group, a hydroxyl group, an amide group, an imide group, a urethane group, a urea group, a sulfonyl group, or a sulfo group contained in the aromatic compound (B). It is done.

  In addition, when using a polyester resin or polycarbonate resin as a matrix resin, interaction such as covalent bond between the carboxyl group or hydroxyl group at the end of the polyester resin or polycarbonate resin and the epoxy group contained in the sizing agent, the main chain Strong interface due to hydrogen bonding between the ester group in the sizing agent, particularly the epoxy group, hydroxyl group, amide group, imide group, urethane group, urea group, sulfonyl group, or sulfo group contained in the aromatic compound (B) It is thought that can be formed. In particular, it is considered that high adhesiveness can be obtained by the interaction between the aromatic ring in the thermoplastic resin and the aromatic compound (B) of the sizing agent.

  Particularly in the second method, preferable thermoplastic resins include, for example, (meth) acrylic resins such as polymethyl methacrylate, polystyrene resins such as polystyrene, vinyl acetate resins, vinyl chloride resins, polyester resins, polypropylene, polyethylene, Examples include polycarbonate. Among these, (meth) acrylic resins having good weather resistance are particularly preferable.

  In the second method, when a thermoplastic resin is used as the matrix resin, a polymerizable monomer of the thermoplastic resin can be blended in order to ensure fluidity during molding. The polymerizable monomer of the thermoplastic resin acts so as to improve the formability when forming into a carbon fiber reinforced composite material. Moreover, since a polymerizable monomer improves the wettability to carbon fiber, a larger amount of carbon fiber can be contained in the molding material. The polymerizable monomer is capable of forming a thermoplastic polymer during polymerization. Such a polymerizable monomer is, for example, a molecule having one radically polymerizable carbon-carbon double bond in the molecule and a molecular weight of 1000 or less. By using a polymerizable monomer having one carbon-carbon double bond in the molecule, a carbon fiber reinforced composite material obtained by polymerizing and curing a molding material containing this is made of a non-crosslinked polymer and exhibits thermoplasticity. To do. Accordingly, material recycling is possible for the molding material using the thermosetting resin of the present invention as the matrix resin.

  Specific examples of the polymerizable monomer for the thermoplastic resin include aromatic vinyl such as styrene, vinyl acetate, vinyl chloride, maleic anhydride, maleic acid, fumaric acid, fumaric acid ester, methyl methacrylate and methacrylic acid ( ) Acrylic monomer is used as an example. These monomers can be used alone or in combination of two or more as required. In addition, the polymerizable monomer of the thermoplastic resin may be in the form of an oligomer such as the polymerizable monomer as long as it can impart appropriate fluidity to the molding material. Among these, (meth) acrylic monomers having good weather resistance after curing are particularly preferable.

In the second method, when a thermosetting resin is used as the matrix resin, it is used as a film-like sheet in which a molten resin is uniformly applied on a release film. A bundle of sizing agent-coated carbon fibers cut in the cutting step is uniformly dropped or dispersed on the sheet, and then a sheet coated with a molten resin is bonded together to sandwich the carbon fiber to form a composite. By heating the obtained sheet for a predetermined time (for example, at 40 ° C. for 24 hours), the viscosity of the matrix resin can be increased and the sheet which is the molding material of the present invention can be obtained.
In the second method, when a thermoplastic resin is used as the matrix resin, the thermoplastic resin is used as a film-like sheet in which a molten resin is uniformly applied on a release film, similarly to the thermosetting resin. When using the thermoplastic resin which mix | blended the polymerizable monomer, it is preferable to set it as the viscosity which does not cause dripping from the side of a release film. A bundle of sizing agent-coated carbon fibers cut in a cutting process is uniformly dropped or dispersed on a sheet coated with a thermoplastic resin, and then a sheet coated with a molten resin is bonded together to sandwich the carbon fiber. Turn into.

  The molding material of the present invention is subjected to ultrasonic treatment in a solvent that dissolves the matrix resin constituting the molding material, so that the amount of sizing agent attached to the surface of the sizing agent-coated carbon fiber is 0.09 to 0.20 mass. The surface of the carbon fiber coated with the sizing agent, which has been washed up to 50%, is (a) CHx, C-C of the C1s inner shell spectrum measured at a photoelectron escape angle of 55 ° by X-ray photoelectron spectroscopy using 400 eV X-ray. , The height (cps) of the component of the binding energy (284.6 eV) attributed to C = C, and (b) the height (cps) of the component of the binding energy (286.1 eV) attributed to C—O. It is preferable that the ratio (a) / (b) is 0.3 to 0.7. It is preferable that (a) / (b) is 0.3 or more because the interaction between the matrix resin and the sizing agent is improved. More preferably, it is 0.35 or more. Moreover, since (a) / (b) is 0.7 or less, since the adhesiveness of carbon fiber and a sizing agent improves, it is preferable because the physical property of a carbon fiber composite material becomes favorable. More preferably, it is 0.6 or less. The solvent for eluting the matrix resin and the sizing agent of the molding material is not limited as long as the matrix resin can be dissolved and the amount of the sizing agent after washing falls within the above range. For example, formic acid is used when a polyamide resin is used as the matrix resin, and dichloromethane is preferably used when a polycarbonate resin is used.

  The molding material of the present invention may contain other components other than those described above depending on the application, etc., as long as the mechanical properties are not impaired, and may contain fillers, additives, and the like. Good. As fillers or additives, inorganic fillers, flame retardants, conductivity imparting agents, crystal nucleating agents, ultraviolet absorbers, antioxidants, vibration damping agents, antibacterial agents, insect repellents, deodorants, coloring inhibitors, heat Stabilizers, mold release agents, antistatic agents, plasticizers, lubricants, colorants, pigments, foaming agents, coupling agents and the like can be mentioned.

  As an additive, the addition of a flame retardant is particularly preferably used for applications that require flame retardancy, and the addition of a conductivity imparting agent for applications that require electrical conductivity. Examples of the flame retardant include flame retardants such as halogen compounds, antimony compounds, phosphorus compounds, nitrogen compounds, silicone compounds, fluorine compounds, phenol compounds, and metal hydroxides. Among these, from the viewpoint of suppressing environmental burden, phosphorus compounds such as ammonium polyphosphate, polyphosphazene, phosphate, phosphonate, phosphinate, phosphine oxide, and red phosphorus can be preferably used.

  Examples of the conductivity imparting agent that can be used include carbon black, amorphous carbon powder, natural graphite powder, artificial graphite powder, expanded graphite powder, pitch microbeads, vapor-grown carbon fiber, and carbon nanotube.

  Applications of the carbon fiber reinforced composite material formed by molding the molding material of the present invention include, for example, personal computers, displays, OA equipment, mobile phones, personal digital assistants, facsimiles, compact discs, portable MDs, portable radio cassettes, PDAs (Personal digital assistants such as electronic notebooks), video cameras, digital still cameras, optical equipment, audio equipment, air conditioners, lighting equipment, entertainment equipment, toy products, other electrical appliances such as housings, trays, chassis, etc. Interior materials and cases, mechanical parts, panels and other building materials applications, motor parts, alternator terminals, alternator connectors, IC regulators, light meter potentiometer bases, suspension parts, exhaust gas valves and other valves, fuel-related, exhaust systems Or suck Various 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 hot air flow control valve, brush holder for radiator motor, water pump Impeller, turbine vane, wiper motor related parts, distributor, starter switch, starter , Wire harness for transmission, window washer nozzle, air conditioner panel switch board, coil for fuel related electromagnetic valve, connector for fuse, 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 device case, under cover, scuff plate, Pillar trim, propeller shaft, wheel, fender, fascia, bumper, bumper beam, Bonnets, aero parts, platforms, cowl louvers, roofs, instrument panels, spoilers and various modules, automobile-related parts, parts and skins, landing gear pods, winglets, spoilers, edges, ladders, elevators, and failings And aircraft related parts such as ribs, members and outer plates, 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. The production environment and evaluation of the molding materials of the following examples are conducted in an atmosphere of a temperature of 25 ° C. ± 2 ° C. and 50% RH (relative humidity) unless otherwise specified.

(1) X-ray photoelectron spectroscopy of sizing agent-coated carbon fiber sizing agent surface (X-ray source: AlKα _1,2 )
In the present invention, the peak ratio of (a) and (b) on the surface of the sizing agent-coated carbon fiber was determined by X-ray photoelectron spectroscopy according to the following procedure. Cut the sizing agent-coated carbon fiber to 20 mm, and spread and arrange it on a copper sample support. Then, use AlKα _1,2 as the X-ray source and keep the sample chamber at 1 × 10 ⁻⁸ Torr for measurement. It was. As correction of the peak accompanying charging during measurement, first, the binding energy value of the main peak of C _1s was adjusted to 286.1 eV. At this time, the peak area of C _1s was obtained by drawing a straight baseline in the range of 282 to 296 eV. Further, a linear base line of 282 to 296 eV obtained by calculating the area at the C _1s peak is defined as the origin (zero point) of the photoelectron intensity, and (b) the peak of the binding energy 286.1 eV attributed to the CO component is obtained. The height (cps: photoelectron intensity per unit time) and the height (cps) of the component having a binding energy of 284.6 eV attributed to (a) CHx, C—C, C = C are obtained, and (a) / ( b) was calculated.
Incidentally, when the peak of from (a) is large _(b), when combined binding energy of the main peak of _{C 1s} to _286.1, the peak of _{C 1s} does not fall within the scope of 282～296EV. In that case, after adjusting the binding energy value of the C _1s main peak to 284.6 eV, (a) / (b) was calculated by the above method.

(2) Cleaning of sizing agent of sizing agent-coated carbon fiber 2 g of sizing agent-coated carbon fiber was immersed in 50 ml of acetone and subjected to ultrasonic cleaning for 30 minutes three times. Subsequently, the substrate was immersed in 50 ml of methanol, subjected to ultrasonic cleaning for 30 minutes once and dried.

(3) X-ray photoelectron spectroscopy at 400 eV of sizing agent-coated carbon fiber In the present invention, the peak ratio of (a) and (b) on the sizing agent-coated carbon fiber surface is determined by X-ray photoelectron spectroscopy. It was determined according to the following procedure. The sizing agent-coated carbon fiber and the sizing agent-coated carbon fiber washed with the sizing agent are cut to 20 mm, spread and arranged on a copper sample support, and then Saga synchroton radiation is used as an X-ray source, and the excitation energy is 400 eV. It carried out in. The measurement was performed while keeping the inside of the sample chamber at 1 × 10 ⁻⁸ Torr. The photoelectron escape angle was 55 °. As correction of the peak accompanying charging during measurement, first, the binding energy value of the main peak of C _1s was adjusted to 286.1 eV. At this time, the peak area of C _1s was obtained by drawing a straight baseline in the range of 282 to 296 eV. Further, a linear base line of 282 to 296 eV obtained by calculating the area at the C _1s peak is defined as the origin (zero point) of the photoelectron intensity, and (b) the peak of the binding energy 286.1 eV attributed to the CO component is obtained. Obtain the height (cps: photoelectron intensity per unit time) and (a) the height (cps) of the component having a binding energy of 284.6 eV attributed to CHx, C—C, C = C. (B) was calculated.
Incidentally, when the peak of from (a) is large _(b), when combined binding energy of the main peak of _{C 1s} to _286.1, the peak of _{C 1s} does not fall within the scope of 282～296EV. In that case, after adjusting the binding energy value of the C _1s main peak to 284.6 eV, (a) / (b) was calculated by the above method.

(4) Strand tensile strength and elastic modulus of carbon fiber bundles Strand tensile strength and strand elastic modulus of carbon fiber bundles 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.

(5) 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 was set in the sample chamber, and the inside of the sample chamber was kept at 1 × 10 ⁻⁸ Torr. Subsequently, AlKα ₁ and ₂ were used as the X-ray source, and the photoelectron escape angle was 90 °. In addition, the binding energy value of the C _1s main peak (peak top) was adjusted to 284.6 eV as a correction value for the peak accompanying charging during measurement. The C _1s peak area was determined by drawing a straight base line in the range of 282 to 296 eV. The O _1s peak area was determined by drawing a straight base line in the range of 528 to 540 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.

(6) Carbon fiber surface carboxyl group concentration (COOH / C), surface hydroxyl group concentration (COH / C)
The surface hydroxyl group concentration (COH / C) was determined by chemical modification X-ray photoelectron spectroscopy according to the following procedure.
The carbon fiber bundles from which the sizing agent and the like have been removed with a solvent are cut and spread and arranged on a platinum sample support. At room temperature in dry nitrogen gas containing 0.04 mol / liter of anhydrous trifluoride acetic acid gas. After 10 minutes exposure and chemical modification treatment, it was mounted on an X-ray photoelectron spectrometer with a photoelectron escape angle of 35 °, AlKα _1,2 was used as an X-ray source, and the inside of the sample chamber was at a vacuum of 1 × 10 ⁻⁸ Torr. Keep on. As correction of the peak accompanying charging during measurement, first, the binding energy value of the main peak of C _1s is adjusted to 284.6 eV. The C _1s peak area [C _1s ] is obtained by drawing a straight base line in the range of 282 to 296 eV, and the F _1s peak area [F _1s ] is obtained by drawing a straight base line in the range of 682 to 695 eV. Asked. Moreover, the reaction rate r was calculated | required from _C1s peak division _| segmentation of the polyvinyl alcohol chemically modified simultaneously.
The surface hydroxyl group concentration (COH / C) was represented by the value calculated by the following formula.
COH / C = {[F _1s ] / (3k [C _1s ] −2 [F _1s ]) r} × 100 (%)
Note that k is a sensitivity correction value of the F _1s peak area with respect to the C _1s peak area specific to the apparatus, and the sensitivity correction value specific to the apparatus in the model SSX-100-206 manufactured by SSI of the United States was 3.919. .

The surface carboxyl group concentration (COOH / C) was determined by chemical modification X-ray photoelectron spectroscopy according to the following procedure. First, carbon fiber bundles from which the sizing agent and the like have been removed with a solvent are cut and spread and arranged on a platinum sample support, and 0.02 mol / liter of trifluorinated ethanol gas, 0.001 mol / liter of dicyclohexyl. The sample was exposed to air containing carbodiimide gas and 0.04 mol / liter pyridine gas at 60 ° C for 8 hours, chemically modified, mounted on an X-ray photoelectron spectrometer with a photoelectron escape angle of 35 °, and used as an X-ray source. Using AlKα ₁ and ₂ , the inside of the sample chamber is kept at a vacuum of 1 × 10 ⁻⁸ Torr. As correction of the peak accompanying charging during measurement, first, the binding energy value of the main peak of C _1s is adjusted to 284.6 eV. The C _1s peak area [C _1s ] is obtained by drawing a straight base line in the range of 282 to 296 eV, and the F _1s peak area [F _1s ] is obtained by drawing a straight base line in the range of 682 to 695 eV. Asked. Simultaneously, the reaction rate r was determined from the C _1s peak splitting of the polyacrylic acid chemically modified, and the residual rate m of the dicyclohexylcarbodiimide derivative was determined from the O _1s peak splitting.
The surface carboxyl group concentration COOH / C was represented by the value calculated by the following formula.
COOH / C = {[F _1s ] / (3k [C _1s ] − (2 + 13 m) [F _1s ]) r} × 100 (%)
Note that k is a sensitivity correction value of the F _1s peak area with respect to the C _1s peak area unique to the apparatus, and the sensitivity correction value specific to the apparatus when the model SSX-100-206 manufactured by SSI of the United States is used is 3.919. Met.

(7) Epoxy equivalent of the sizing agent, epoxy equivalent of the sizing agent applied to the carbon fiber The epoxy equivalent of the sizing agent is obtained by dissolving the solvent-free sizing agent in N, N-dimethylformamide and opening the epoxy group with hydrochloric acid. Ringed and determined by acid-base titration. The epoxy equivalent of the sizing agent applied to the carbon fiber is determined by immersing the sizing agent-coated carbon fiber in N, N-dimethylformamide and elution from the fiber by ultrasonic cleaning, and then opening the epoxy group with hydrochloric acid. Ringed and determined by acid-base titration.

(8) Measuring method of sizing adhesion amount Electric furnace set to a temperature of 450 ° C. in a nitrogen stream of 50 ml / min after weighing (W1) about 2 g of sizing adhesion carbon fiber (reading to the fourth decimal place) Leave in (capacity 120 cm ³ ) for 15 minutes to completely pyrolyze the sizing agent. Then, the carbon fiber bundle is transferred to a container in a dry nitrogen stream at 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.

(9) Moisture measurement of sizing agent-coated carbon fiber About 2 g of sizing agent-coated carbon fiber was weighed, and the moisture content was measured using KF-100 (capacitance method Karl Fischer moisture meter) manufactured by Mitsubishi Chemical Analytech. The heating temperature at the time of measurement was 150 ° C.

(10) Ratio of eluted aliphatic epoxy compound (A) 0.1 g of a sizing agent-coated carbon fiber test piece was weighed and cut into several centimeters. The cut specimen was immersed in 10 mL of an acetonitrile / chloroform mixture (volume ratio 9/1) and subjected to ultrasonic cleaning for 20 minutes to elute the sizing agent into the acetonitrile / chloroform mixture. 5 mL of the eluate was collected, and the collected eluate was purged with nitrogen to distill off the solvent. An analytical sample was prepared by adding 0.2 mL of acetonitrile / chloroform mixture (volume ratio 9/1) to the residue after the solvent was distilled off. Analysis of the aliphatic epoxy compound (A) was performed under the following conditions using liquid chromatography.
・ Analytical column: Chromolis Performance RP-18e (4.6 × 100 mm)
-Mobile phase: Water / acetonitrile was used, and after 7 minutes from the start of analysis, water / acetonitrile = 60% / 40% to acetonitrile 100%, then 100% acetonitrile was retained for 12 minutes, and then 12.1 minutes By the time, water / acetonitrile = 60% / 40%, and water / acetonitrile = 60% / 40% was maintained until 17 minutes.
-Flow rate: 2.5 mL / min-Column temperature: 45 ° C
Detector: Evaporative light scattering detector (ELSD)
-Detector temperature: 60 ° C

(11) Bending characteristic evaluation method of molded product A bending strength test piece having a length of 130 ± 1 mm and a width of 25 ± 0.2 mm was cut out from a carbon fiber reinforced composite material obtained by molding a molding material. According to the test method specified in ASTM D-790 (2004), using a three-point bending test jig (indenter 10 mm, fulcrum 10 mm), the support span is set to 100 mm, and the bending strength is measured at a crosshead speed of 5.3 mm / min. did. In this example, “Instron (registered trademark)” universal testing machine 4201 type (manufactured by Instron) was used as a testing machine. The number of measurements was n = 5, and the average value was the bending strength.

(12) Decreasing rate of bending strength at the time of water absorption of the molded article About a molded article obtained by using polyamide as a thermoplastic resin, the test piece is immersed in water to absorb 2.5% of water with respect to the test piece. The bending characteristics were evaluated. As a result, with respect to the bending strength obtained in (10), the drop rate was 60% or less as a preferable range, and when it was greater than 60%, the drop rate was high, and x.

(13) Carbon fiber surface roughness (Ra)
The surface roughness (Ra) of the carbon fiber was measured with an atomic force microscope (AFM). Prepare a carbon fiber cut to several millimeters in length, fix it on a substrate (silicon wafer) using silver paste, and use a three-dimensional surface at the center of each single fiber with an atomic force microscope (AFM). An image of the shape was observed. As an atomic force microscope, a Dimension 3000 stage system was used in NanoScope IIIa manufactured by Digital Instruments and observed under the following observation conditions.
・ Scanning mode: Tapping mode ・ Probe: Silicon cantilever ・ Scanning range: 0.6μm × 0.6μm
・ Scanning speed: 0.3Hz
-Number of pixels: 512 × 512
・ Measurement environment: Room temperature, in air

The materials and components used in each example and each comparative example are as follows.
-(A) component: A-1 to A-2
A-1: “Denacol (registered trademark)” EX-611 (manufactured by Nagase ChemteX Corporation)
Sorbitol polyglycidyl ether Epoxy equivalent: 167 g / eq. ,
A-2: “Denacol (registered trademark)” EX-521 (manufactured by Nagase ChemteX Corporation)
Polyglycerin polyglycidyl ether Epoxy equivalent: 183 g / eq. , Surface tension at 125 ° C. 37 mJ / m ²

-(B1) component: B-1 to B-4
B-1: “jER (registered trademark)” 152 (manufactured by Mitsubishi Chemical Corporation)
Glycidyl ether of phenol novolac Epoxy equivalent: 175 g / eq. , Surface tension at 125 ° C. 40 mJ / m ²
B-2: “jER (registered trademark)” 828 (manufactured by Mitsubishi Chemical Corporation)
Diglycidyl ether of bisphenol A Epoxy equivalent: 189 g / eq. , Surface tension at 125 ° C. 38 mJ / m ²
B-3: “jER (registered trademark)” 1001 (manufactured by Mitsubishi Chemical Corporation)
Diglycidyl ether of bisphenol A Epoxy equivalent: 475 g / eq. , Surface tension at 125 ° C. 38 mJ / m ²
B-4: “jER (registered trademark)” 807 (manufactured by Mitsubishi Chemical Corporation)
Diglycidyl ether of bisphenol F Epoxy equivalent: 167 g / eq. , Surface tension at 125 ° C. 40 mJ / m ²

-Matrix resin polyarylene sulfide (PPS) resin film: "Torelina (registered trademark)" M2888 (manufactured by Toray Industries, Inc.) processed into a film (100 g / m ² basis weight)
Polyamide 6 (PA6) resin film: “Amilan (registered trademark)” CM1001 (manufactured by Toray Industries, Inc.) processed into a film (100 g / m ² basis weight)
Vinyl ester resin (VE) resin film: 100 parts by mass of vinyl ester resin (Dow Chemical Co., Ltd., Delaken 790), 1 part by mass of tert-butyl peroxybenzoate (Nippon Yushi Co., Ltd., Perbutyl Z), stearin On a release film made of polypropylene, a resin paste in which 2 parts by mass of zinc oxide (manufactured by Sakai Chemical Industry Co., Ltd., SZ-2000) and 4 parts by mass of magnesium oxide (manufactured by Kyowa Chemical Industry Co., Ltd., MgO # 40) are mixed (Applicable weight is 400 g / m ² )
Polypropylene (PP) resin film (polyolefin resin): Unmodified PP resin pellets and acid-modified PP resin pellets are mixed and processed into a film (100 g / m ² basis weight, unmodified PP resin pellets: “Prime Polypro (registered trademark)” "J830HV (manufactured by Prime Polymer Co., Ltd.)) 50 parts by mass, acid-modified PP resin pellet:" Admer (registered trademark) "QE800 (manufactured by Mitsui Chemicals, Inc.) 50 parts by mass)

Example 1
The present embodiment includes the following steps I to IV.
-Step I: Process for producing carbon fiber as a raw material A copolymer composed of 99 mol% acrylonitrile and 1 mol% itaconic acid is dry-wet spun, fired, total number of filaments 24,000, total fineness 1 , Tex, 1.8 specific gravity, strand tensile strength of 5.9 GPa, and strand tensile elastic modulus of 295 GPa were obtained. Next, 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 / liter 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 0.14, the surface carboxyl group concentration COOH / C was 0.004, and the surface hydroxyl group concentration COH / C was 0.018. The carbon fiber surface roughness (Ra) at this time was 2.9 nm. Then, the obtained carbon fiber was cut into 6 mm with a cartridge cutter. This was designated as carbon fiber A.
Step II: Process for producing a papermaking web Concentration of 0.1 mass comprising water and a surfactant (manufactured by Nacalai Tex Co., Ltd., polyoxyethylene lauryl ether (trade name)) in a cylindrical container having a diameter of 500 mm % Dispersion liquid was added, and the carbon fiber cut in the previous step was put therein so that the mass content of the fiber was 0.02%. After stirring for 5 minutes, dehydration was performed to obtain a papermaking web (Form A). The basis weight at this time was 67 g / m ² .

-Step III: Step of applying a sizing agent to the papermaking web (B1) After preparing an aqueous dispersion emulsion comprising 20 parts by weight of (B-2), 20 parts by weight of component (C) and 10 parts by weight of emulsifier A sizing solution was prepared by mixing 50 parts by mass of (A-1) as the component (A). As component (C), 2 mol of EO 2 mol adduct of bisphenol A, 1.5 mol of maleic acid and 0.5 mol of sebacic acid, polyoxyethylene (70 mol) as a emulsifier, styrenation (5 mol) Cumylphenol was used. In addition, (C) component and an emulsifier are both aromatic compounds, and will also correspond to (B) component. The epoxy equivalent of the sizing agent excluding the solution in the sizing solution is as shown in Table 1-1. Next, a sizing solution was sprayed from the papermaking web obtained in the previous step. Thereafter, after surplus sizing solution was sucked, heat treatment was performed at 210 ° C. × 180 seconds. The adhesion amount of the sizing agent was 0.6 parts by mass with respect to 100 parts by mass of the carbon fiber. Subsequently, the epoxy equivalent of the sizing agent-coated carbon fiber, the moisture content of the sizing agent-coated carbon fiber, and the X-ray photoelectron spectroscopy measurement on the sizing agent surface were measured. It was found that the epoxy equivalent of the sizing agent and the chemical composition of the sizing agent surface were as expected. The results are shown in Table 1-1.
Step IV: Compounding process of papermaking web and thermoplastic resin PPS resin film (resin weight 100 g / m ² ) is sandwiched from above and below in the papermaking web obtained in the previous process, and at 330 ° C. with a hot press machine, After heating and pressurizing at 3.5 MPa, cooling and pressurizing was performed at 60 ° C. and 3.5 MPa to obtain a molding material in which a papermaking web and a PPS resin were combined. Furthermore, lamination, heating and pressing, and cooling and pressing were performed so that the thickness of the molded product was 3 mm. The obtained molded product had a carbon fiber content of 25% by mass. The molded article was left for 24 hours in a constant temperature and humidity chamber adjusted to a temperature of 23 ° C. and 50% RH, and then subjected to a characteristic evaluation test. Next, the obtained test piece for characteristic evaluation was evaluated according to the above-described molded product evaluation method. The results are summarized in Table 1-1. As a result, it was found that the bending strength was 446 MPa and the mechanical properties were sufficiently high.

(Examples 2 to 10)
-Steps I to II:
Same as Example 1.
Step III: Step of applying a sizing agent to the papermaking web In Step III of Example 1, the types and amounts of components (A) and (B1), (C1), and the amounts of other components are shown in Table 1- A papermaking web provided with a sizing agent was obtained in the same manner as in Example 1 except that it was used as described in Example 1. The adhesion amount of the sizing agent was 0.6 parts by mass with respect to 100 parts by mass of the surface-treated carbon fiber.
Step IV: Compounding step of papermaking web and thermoplastic resin A test piece for property evaluation was molded in the same manner as in Example 1. Next, the obtained test piece for characteristic evaluation was evaluated according to the above-described molded product evaluation method. The results are summarized in Table 1-1. As a result, it was found that the bending strength was 437 to 448 MPa, and the mechanical properties were sufficiently high.

(Example 11)
-Steps I to II:
Same as Example 1.
Step III: A step of applying a sizing agent to the papermaking web A sizing agent was prepared in the same manner as in Step III of Example 1, and a papermaking web provided with a sizing agent in the same manner as in Example 1 was obtained. It was. The adhesion amount of the sizing agent was 1.0 part by mass with respect to 100 parts by mass of the surface-treated carbon fiber.
Step IV: Compounding step of papermaking web and thermoplastic resin A test piece for property evaluation was molded in the same manner as in Example 1. Next, the obtained test piece for characteristic evaluation was evaluated according to the above-described molded product evaluation method. The results are summarized in Table 1-1. As a result, it was found that the bending strength was 446 MPa and the mechanical properties were sufficiently high.

(Example 12)
-Step I: Step of producing carbon fiber as raw material Implemented except that a sulfuric acid aqueous solution having a concentration of 0.05 mol / l was used as the electrolytic solution, and the electrolytic amount was subjected to electrolytic surface treatment at 8 coulomb per gram of carbon fiber. Same as Example 1. At this time, the surface oxygen concentration O / C was 0.08, the surface carboxyl group concentration COOH / C was 0.003, and the surface hydroxyl group concentration COH / C was 0.003. Then, the obtained carbon fiber was cut into 6 mm with a cartridge cutter. This was designated as carbon fiber B.
-Step II: Step of producing a papermaking web The same as in Example 1.
-Steps III to IV:
A test piece for property evaluation was molded in the same manner as in Example 1. Next, the obtained test piece for property evaluation was evaluated according to the above-described injection molded product evaluation method. The results are summarized in Table 1-1. As a result, it was found that the bending strength is not a problem.

(Example 13)
-Step I: Process for producing carbon fiber as raw material A copolymer consisting of 99 mol% acrylonitrile and 1 mol% itaconic acid is wet-spun, fired, 12,000 total filaments, and total fineness 447 tex A carbon fiber having a specific gravity of 1.8, a strand tensile strength of 5.6 GPa, and a 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 40 coulomb per 1 g of the 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 roughness (Ra) of the carbon fiber is 23 nm, the surface oxygen concentration O / C is 0.13, the surface carboxyl group concentration COOH / C is 0.005, and the surface hydroxyl group concentration COH / C is 0.018. there were. The carbon fiber surface roughness (Ra) at this time was 2.9 nm. Then, the obtained carbon fiber was cut into 6 mm with a cartridge cutter. This was designated as carbon fiber C.
-Step II: Step of producing a papermaking web The same as in Example 1.
-Steps III to IV:
A test piece for property evaluation was molded in the same manner as in Example 1. Next, the obtained test piece for property evaluation was evaluated according to the above-described injection molded product evaluation method. The results are summarized in Table 1-1. As a result, it was found that the bending strength is not a problem.

(Example 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 (A) Component, (B1) Component was used as shown in Table 1-1, and (A) and (B1) were made into a solution using dimethylformamide. The carbon fiber which apply | coated the sizing agent by the method similar to Example 1 was obtained except that. Subsequently, the epoxy equivalent of the sizing agent, the moisture content of the sizing agent-coated carbon fiber, and the X-ray photoelectron spectroscopy measurement of the sizing agent surface were performed. Both the epoxy equivalent of the sizing agent and the chemical composition of the sizing agent surface were as expected. The results are shown in Table 1-1.
-Steps III to IV:
A test piece for property evaluation was molded in the same manner as in Example 1. Next, the obtained test piece for property evaluation was evaluated according to the above-described injection molded product evaluation method. The results are summarized in Table 1-1. As a result, it was found that the bending strength was high.

(Comparative Example 1)
-Steps I to II:
Same as Example 1.
-Step III: Step of applying a sizing agent to the papermaking web (A) Without using the component (B1) Examples except that the type and amount of the component and the amounts of other components were used as shown in Table 1-2 A papermaking web to which a sizing agent was applied was obtained in the same manner as in 1. The adhesion amount of the sizing agent was 0.6 parts by mass with respect to 100 parts by mass of the surface-treated carbon fiber. Subsequently, when X-ray photoelectron spectroscopy measurement was performed on the surface of the sizing agent, it was outside the scope of the present invention as shown in Table 1-2.
Step IV: Compounding step of papermaking web and thermoplastic resin A test piece for property evaluation was molded in the same manner as in Example 1. Next, the obtained test piece for characteristic evaluation was evaluated according to the above-described molded product evaluation method. The results are summarized in Table 1-2. As a result, it was found that the bending strength was 415 MPa and the mechanical properties were insufficient.

(Comparative Example 2)
-Steps I to II:
Same as Example 1.
-Step III: Step of applying a sizing agent to the papermaking web (B1) The same method as in Example 1 except that the component (A) is not used and the type and amount of the component (A) are used as shown in Table 1-2. Thus, a papermaking web provided with a sizing agent was obtained. The adhesion amount of the sizing agent was 0.6 parts by mass with respect to 100 parts by mass of the surface-treated carbon fiber. Subsequently, when X-ray photoelectron spectroscopy measurement was performed on the surface of the sizing agent, it was outside the scope of the present invention as shown in Table 1-2.
Step IV: Compounding step of papermaking web and thermoplastic resin A test piece for property evaluation was molded in the same manner as in Example 1. Next, the obtained test piece for characteristic evaluation was evaluated according to the above-described molded product evaluation method. As a result, it was found that the bending strength was as shown in Table 1-2 and the mechanical properties were slightly low.

(Comparative Examples 3 and 4)
-Steps I to II:
Same as Example 1.
-Step III: Step of applying a sizing agent to the papermaking web (A), (B1) Kinds and amounts of components, (C1), except that the amounts of other components were used as shown in Table 1-2. A papermaking web provided with a sizing agent was obtained in the same manner as in Example 1. Subsequently, when X-ray photoelectron spectroscopy measurement was performed on the surface of the sizing agent, it was outside the scope of the present invention as shown in Table 1-2.
-Steps III to IV:
A test piece for property evaluation was molded in the same manner as in Example 1. Next, the obtained test piece for characteristic evaluation was evaluated according to the above-described molded product evaluation method. As a result, it was found that the bending strength was as shown in Table 1-2 and the mechanical properties were insufficient.

(Comparative Example 5)
-Steps I to II:
Same as Example 1.
-Step III: A step of applying a sizing agent to the papermaking web (A) The aqueous solution of (A-2) is prepared as a component, sprayed on the papermaking web by a dipping method, and the excess is sucked, and then 210 ° C Heat treatment was performed at temperature for 75 seconds to obtain a papermaking web to which a sizing agent was applied. The adhesion amount of the sizing agent was adjusted to 0.30% by mass with respect to the finally obtained sizing agent-coated carbon fiber (sizing agent-coated papermaking web). Subsequently, an aqueous dispersion emulsion comprising 20 parts by mass of (B-2), 20 parts by mass of (C) component, and 10 parts by mass of an emulsifier was prepared as the component (B1). As component (C), 2 mol of EO 2 mol adduct of bisphenol A, 1.5 mol of maleic acid and 0.5 mol of sebacic acid, polyoxyethylene (70 mol) as a emulsifier, styrenation (5 mol) Cumylphenol was used. In addition, (C) component and an emulsifier are both aromatic compounds, and will also correspond to (B) component. This sizing agent was sprayed on the papermaking web coated with the component (A) by the dipping method, and after surplus was sucked, heat treatment was performed at a temperature of 210 ° C. for 75 seconds to obtain a papermaking web coated with the sizing agent. The adhesion amount of the sizing agent was adjusted to 0.30 parts by mass with respect to the finally obtained sizing agent-coated carbon fiber (sizing agent-coated papermaking web). X-ray photoelectron spectroscopy measurements on the sizing agent surface were measured. Component of binding energy (284.6 eV) attributed to (a) CHx, C—C, C = C of C _1s inner shell spectrum measured by X-ray photoelectron spectroscopy on the sizing agent surface at a photoelectron escape angle of 15 ° The ratio (a) / (b) of the height (cps) of the component (b) and the height (cps) of the component of the binding energy (286.1 eV) attributed to C—O is greater than 0.90. Was out of range.
-Steps III to IV:
A test piece for property evaluation was molded in the same manner as in Example 1. Next, the obtained test piece for characteristic evaluation was evaluated according to the above-described molded product evaluation method. As a result, it was found that the bending strength was as shown in Table 1-2 and the mechanical properties were low.

(Example 15)
-Step I: Step of producing carbon fiber as a raw material The same as in Example 1.
Step II: Process for producing a papermaking web Concentration of 0.1 mass consisting of water and a surfactant (manufactured by Nacalai Tex Co., Ltd., polyoxyethylene lauryl ether (trade name)) in a cylindrical container having a diameter of 500 mm % Dispersion liquid was added, and the carbon fiber cut in the previous step was put therein so that the mass content of the fiber was 0.02 mass%. After stirring for 5 minutes, dehydration was performed to obtain a papermaking web. The basis weight at this time was 103 g / m ² .
Step III: Step of applying a sizing agent to the papermaking web Same as Example 1.
Step IV: Compounding process of papermaking web and thermoplastic resin A PP resin film (resin weight 100 g / m ² ) is sandwiched from above and below in the papermaking web obtained in the previous process, and heated at 240 ° C. with a hot press machine. After heating and pressurizing at 3.5 MPa, cooling and pressurizing were performed at 60 ° C. and 3.5 MPa to obtain a molding material in which the papermaking web and PP resin were combined. Furthermore, lamination, heating and pressing, and cooling and pressing were performed so that the thickness of the molded product was 3 mm. The obtained molded article had a carbon fiber content of 34% by mass. The molded article was left for 24 hours in a constant temperature and humidity chamber adjusted to a temperature of 23 ° C. and 50% RH, and then subjected to a characteristic evaluation test. Next, the obtained test piece for characteristic evaluation was evaluated according to the above-described molded product evaluation method. The results are summarized in Table 2. As a result, it was found that the bending strength was 314 MPa and the mechanical properties were sufficiently high.

(Examples 16 to 20)
-Steps I to II:
Same as Example 1.
-Step III: Steps (A) and (B1) for applying a sizing agent to a papermaking web. Got the web. The adhesion amount of the sizing agent was 0.6 parts by mass with respect to 100 parts by mass of the surface-treated carbon fiber.
Step IV: Compounding Step of Papermaking Web and Thermoplastic Resin A test piece for property evaluation was molded in the same manner as in Example 15. Next, the obtained test piece for characteristic evaluation was evaluated according to the above-described molded product evaluation method. The results are summarized in Table 2. As a result, it was found that the bending strength was 306 to 318 MPa, and the mechanical properties were sufficiently high.

(Comparative Example 6)
-Steps I to II:
Same as Example 1.
-Step III: Step of applying a sizing agent to the papermaking web.
Step IV: Compounding Step of Papermaking Web and Thermoplastic Resin A test piece for property evaluation was molded in the same manner as in Example 15. Next, the obtained test piece for characteristic evaluation was evaluated according to the above-described molded product evaluation method. As a result, it was found that the bending strength was as shown in Table 2 and the mechanical properties were insufficient.

(Comparative Example 7)
-Steps I to II:
Same as Example 1.
-Step III: Step of applying a sizing agent to the papermaking web.
Step IV: Compounding Step of Papermaking Web and Thermoplastic Resin A test piece for property evaluation was molded in the same manner as in Example 15. Next, the obtained test piece for characteristic evaluation was evaluated according to the above-described molded product evaluation method. As a result, it was found that the bending strength was as shown in Table 2 and the mechanical properties were slightly low.

(Example 21)
-Step I: Step of producing carbon fiber as a raw material The same as in Example 1.
Step II: Process for producing a papermaking web Concentration of 0.1 mass consisting of water and a surfactant (manufactured by Nacalai Tex Co., Ltd., polyoxyethylene lauryl ether (trade name)) in a cylindrical container having a diameter of 500 mm % Dispersion liquid was added, and the carbon fiber cut in the previous step was put therein so that the mass content of the fiber was 0.02 mass%. After stirring for 5 minutes, dehydration was performed to obtain a papermaking web. The basis weight at this time was 82 g / m ² .
Step III: Step of applying a sizing agent to the papermaking web Same as Example 1.
- Part IV: scissors papermaking web and thermoplastic resin composite step previous step resulting paper web PA6 resin film (resin basis weight 100 g / m ²⁾ from the vertical direction, by a heat press apparatus, 300 ° C., After heating and pressurizing at 3.5 MPa, cooling and pressurizing were performed at 60 ° C. and 3.5 MPa to obtain a molding material in which the papermaking web and PA6 resin were combined. Furthermore, lamination, heating and pressing, and cooling and pressing were performed so that the thickness of the molded product was 3 mm. The carbon fiber content of the obtained molded product was 29% by mass. The molded article was left for 24 hours in a constant temperature and humidity chamber adjusted to a temperature of 23 ° C. and 50% RH, and then subjected to a characteristic evaluation test. Next, the obtained test piece for characteristic evaluation was evaluated according to the above-described molded product evaluation method. The results are summarized in Table 3. As a result, it was found that the bending strength was 440 MPa and the mechanical properties were sufficiently high. Moreover, it turned out that the fall rate of the bending strength at the time of moisture absorption is small.

(Examples 22 to 26)
-Steps I to II:
Same as Example 1.
Step III: Steps of applying a sizing agent to a papermaking web (A), (B1) Papermaking provided with a sizing agent in the same manner as in Example 21 except that the types of components were used as shown in Table 3 Got the web. The adhesion amount of the sizing agent was 0.6 parts by mass with respect to 100 parts by mass of the surface-treated carbon fiber.
Step IV: Compounding Step of Papermaking Web and Thermoplastic Resin A test piece for characteristic evaluation was molded in the same manner as in Example 21. Next, the obtained test piece for characteristic evaluation was evaluated according to the above-described molded product evaluation method. The results are summarized in Table 3. As a result, it was found that the bending strength was 443 to 446 MPa, and the mechanical properties were sufficiently high. Moreover, it turned out that the fall rate of the bending strength at the time of moisture absorption is small.

(Comparative Example 8)
-Steps I to II:
Same as Example 1.
-Step III: Step of applying a sizing agent to the papermaking web.
Step IV: Compounding Step of Papermaking Web and Thermoplastic Resin A test piece for characteristic evaluation was molded in the same manner as in Example 21. Next, the obtained test piece for characteristic evaluation was evaluated according to the above-described molded product evaluation method. As a result, it was found that although the rate of decrease in bending strength during moisture absorption was small, the bending strength was insufficient.

(Comparative Example 9)
-Steps I to II:
Same as Example 1.
-Step III: Step of applying a sizing agent to the papermaking web.
Step IV: Compounding Step of Papermaking Web and Thermoplastic Resin A test piece for characteristic evaluation was molded in the same manner as in Example 21. Next, the obtained test piece for characteristic evaluation was evaluated according to the above-described molded product evaluation method. As a result, it was found that although the bending strength was high, the rate of decrease in bending strength during moisture absorption was large.

(Example 27)
-Step I: Step of producing carbon fiber as a raw material The same as in Example 1.
-Step II: A step of attaching a sizing agent to carbon fiber (B1) As a component, an aqueous dispersion emulsion comprising 20 parts by mass of (B-2), 20 parts by mass of component (C) and 10 parts by mass of an emulsifier was prepared. Thereafter, 50 parts by mass of (A-1) as component (A) was mixed to prepare a sizing solution. Table 4 shows the epoxy equivalent of the sizing agent excluding the solution in the sizing solution. After applying this sizing agent to the carbon fiber surface-treated by the dipping method, heat treatment was performed at a temperature of 210 ° C. for 75 seconds to obtain a carbon fiber coated with the sizing agent. The adhesion amount of the sizing agent was adjusted to 0.6% by mass with respect to the carbon fiber coated with the sizing agent. Subsequently, Table 4 summarizes the epoxy equivalent of the sizing agent applied to the carbon fiber, the moisture content of the carbon fiber coated with the sizing agent, the X-ray photoelectron spectroscopy measurement of the sizing agent surface, and the measurement of the eluted aliphatic epoxy compound. It was. As a result, it was confirmed that both the epoxy equivalent of the sizing agent and the chemical composition of the sizing agent surface were as expected.

-Step III: Sizing agent-coated carbon fiber cutting step The sizing agent-coated carbon fiber obtained in Step II was cut into 6 mm with a cartridge cutter.
-Step IV: Compounding process with thermoplastic resin Sizing agent-coated carbon fibers (weight per unit area 86 g / m ² ) cut in the previous process are randomly placed on the PPS resin film, and another sheet of PPS resin is placed thereon. The film was sandwiched and heated and pressurized at 330 ° C. and 5.0 MPa with a hot press apparatus, then cooled and pressurized at 60 ° C. and 5.0 MPa, and the cut sizing agent-coated carbon fiber and PPS resin were combined. A sheet-shaped molding material (form B) was obtained. Furthermore, lamination, heating and pressing, and cooling and pressing were performed so that the thickness of the molded product was 3 mm. The obtained molded product had a carbon fiber content of 30% by mass. The molded article was left for 24 hours in a constant temperature and humidity chamber adjusted to a temperature of 23 ° C. and 50% RH, and then subjected to a characteristic evaluation test. Next, the obtained test piece for characteristic evaluation was evaluated according to the above-described molded product evaluation method. The results are summarized in Table 4. As a result, it was found that the bending strength was 276 MPa and the mechanical properties were sufficiently high.

(Examples 28 to 32)
-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 27, except that the types of components (A) and (B1) were used as shown in Table 4 in Step II of Example 27. Sizing agent-coated carbon fibers coated with a sizing agent were obtained in the same manner. The adhesion amount of the sizing agent was 0.6 parts by mass with respect to 100 parts by mass of the carbon fiber.
Step III: Sizing Agent-Coated Carbon Fiber Cutting Process Same as Example 27.
Step IV: Compounding step with thermoplastic resin A test piece for characteristic evaluation was molded in the same manner as in Example 27. Next, the obtained test piece for characteristic evaluation was evaluated according to the above-described molded product evaluation method. The results are summarized in Table 4. As a result, it was found that the bending strength was 269 to 283 MPa, and the mechanical properties were sufficiently high.

(Comparative Example 10)
-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) Example 27 except that component (B1) was not used, and the type and amount of component and the amount of other components were used as shown in Table 4. A sizing agent-coated carbon fiber was obtained in the same manner as described above. The adhesion amount of the sizing agent was 0.6 parts by mass with respect to 100 parts by mass of the surface-treated carbon fiber. Subsequently, when X-ray photoelectron spectroscopy measurement was performed on the surface of the sizing agent, it was outside the scope of the present invention as shown in Table 4.
-Steps III to IV:
A test piece for property evaluation was molded in the same manner as in Example 27. Next, the obtained test piece for property evaluation was evaluated according to the above-described injection molded product evaluation method. As a result, it was found that the bending strength was as shown in Table 4 and the mechanical properties were insufficient.

(Comparative Example 11)
-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 (B1) Sizing in the same manner as in Example 27, except that component (A) was not used and the type and amount of component (A) were used as shown in Table 4. An agent-coated carbon fiber was obtained. The adhesion amount of the sizing agent was 0.6 parts by mass with respect to 100 parts by mass of the surface-treated carbon fiber. Subsequently, when X-ray photoelectron spectroscopy measurement was performed on the surface of the sizing agent, it was outside the scope of the present invention as shown in Table 4.
-Steps III to IV:
A test piece for property evaluation was molded in the same manner as in Example 27. Next, the obtained test piece for characteristic evaluation was evaluated according to the above-described molded product evaluation method. As a result, it was found that the bending strength was as shown in Table 4 and the mechanical properties were slightly low.

(Example 33)
-Step I: Step of producing carbon fiber as a raw material The same as in Example 1.
Step II: Step of attaching a sizing agent to carbon fibers The same as in Example 27.

-Step III: Sizing agent-coated carbon fiber cutting step The sizing agent-coated carbon fiber obtained in Step II was cut into 6 mm with a cartridge cutter.
Step IV: Compounding step with thermoplastic resin 100 parts by mass of vinyl ester resin (VE, manufactured by Dow Chemical Co., Ltd., Delaken 790) as matrix resin, and tert-butyl peroxybenzoate (Japan) as curing agent 1 part by mass of Perfume Z, manufactured by Yushi Co., Ltd., 2 parts by mass of zinc stearate (manufactured by Sakai Chemical Industry Co., Ltd., SZ-2000) as an internal mold release agent, and magnesium oxide (Kyowa Chemical Industry) as a thickener Using 4 parts by mass of MgO # 40 manufactured by Co., Ltd., they were sufficiently mixed and stirred to obtain a resin paste. The resin paste was applied on a polypropylene release film using a doctor blade so that the weight per unit area was 400 g / m ² . From there, the bundled sizing agent-coated carbon fibers cut in the previous step were uniformly dropped and dispersed. Further, the resin paste was sandwiched with the other polypropylene film coated with the resin paste so that the weight per unit area was 400 g / m ² . Content with respect to the SMC sheet of carbon fiber was 50 mass%. By leaving the obtained sheet at 40 ° C. for 24 hours, the resin paste was sufficiently thickened to obtain a sheet-shaped molding material (Form B).
Charge the sheet-shaped molding material obtained in the previous process to the mold so that the charge rate (the ratio of the area of the sheet-shaped molding material to the mold area when the mold is viewed from above) is 50%. Then, it was cured under conditions of 150 ° C. × 5 minutes under a pressure of 588.4 kPa using a heating press molding machine to obtain a plate-like molded product of 30 cm × 30 cm × 3 mm. Next, the obtained test piece for characteristic evaluation was evaluated according to the above-described molded product evaluation method. The obtained molded article had a carbon fiber content of 50% by mass. The molded article was left for 24 hours in a constant temperature and humidity chamber adjusted to a temperature of 23 ° C. and 50% RH, and then subjected to a characteristic evaluation test. Next, the obtained test piece for characteristic evaluation was evaluated according to the above-described molded product evaluation method. The results are summarized in Table 5. As a result, it was found that the bending strength was 480 MPa and the mechanical properties were sufficiently high.

(Examples 34 to 38)
-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 33, except that component (A) and component (B) were changed as shown in Table 5 in step II of Example 33. A sizing agent-coated carbon fiber was obtained in the same manner as described above. The adhesion amount of the sizing agent was 0.6 parts by mass with respect to 100 parts by mass of the surface-treated carbon fiber.
-Steps III and IV:
A test piece for property evaluation was molded in the same manner as in Example 33. Next, the obtained test piece for characteristic evaluation was evaluated according to the above-described molded product evaluation method. The results are summarized in Table 5. As a result, it was found that the bending strength was 473 to 482 MPa, and the mechanical properties were sufficiently high.

(Comparative Example 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 The same as Comparative Example 10.
-Steps III to IV:
A test piece for property evaluation was molded in the same manner as in Example 33. Next, the obtained test piece for property evaluation was evaluated according to the above-described injection molded product evaluation method. As a result, it was found that the bending strength was as shown in Table 5 and the mechanical properties were insufficient.

(Comparative Example 13)
-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 The same as Comparative Example 11.
-Steps III to IV:
A test piece for property evaluation was molded in the same manner as in Example 33. Next, the obtained test piece for property evaluation was evaluated according to the above-described injection molded product evaluation method. As a result, it was found that the bending strength was as shown in Table 5 and the mechanical properties were slightly low.

(Example 39)
2 g of the sizing agent-coated carbon fiber (paper-making web coated with the sizing agent) obtained in Example 1 was immersed in 50 ml of acetone and subjected to ultrasonic cleaning for 30 minutes three times. Subsequently, the substrate was immersed in 50 ml of methanol, subjected to ultrasonic cleaning for 30 minutes once and dried. When the sizing agent adhesion amount remaining after washing was measured, it was as shown in Table 6-1.
Subsequently, the sizing agent surface of the sizing agent-coated carbon fiber before washing, and the sizing agent-coated carbon fiber sizing agent surface obtained by washing were assigned to (b) CO component by X-ray photoelectron spectroscopy at 400 eV. The peak height of the binding energy of 286.1 eV and the height (cps) of the component of the binding energy of 284.6 eV attributed to (a) CHx, C-C, C = C are obtained, and (I) before washing (A) / (b) on the sizing agent surface of the sizing agent-coated carbon fiber, (II) (a) / (b) on the sizing agent surface of the sizing agent-coated carbon fiber after washing. (I) and (II) / (I) were as shown in Table 6-1.

(Examples 40 and 41)
(A) CHx of the C1s inner shell spectrum by X-ray photoelectron spectroscopy using 400 eV X-rays before and after cleaning using the sizing agent-coated carbon fibers obtained in Example 2 and Example 3 as in Example 39 , C—C, the height (cps) of the component of the bond energy (284.6 eV) attributed to C═C, and (b) the high of the component of the bond energy (286.1 eV) attributed to C—O. The ratio (a) / (b) to the thickness (cps) was obtained. The results are shown in Table 6-1.

(Comparative Example 14)
(A) CHx, C-C of C1s inner shell spectrum by X-ray photoelectron spectroscopy using 400 eV X-rays before and after washing using the sizing agent-coated carbon fiber obtained in Comparative Example 1 as in Example 39. , The height (cps) of the component of the binding energy (284.6 eV) attributed to C = C, and (b) the height (cps) of the component of the binding energy (286.1 eV) attributed to C—O. The ratio (a) / (b) was obtained. The results are shown in Table 6-1, and it was found that (II / I) was large and the sizing agent had no gradient structure.

(Comparative Example 15)
(A) CHx, C-C of C1s inner-shell spectrum by X-ray photoelectron spectroscopy using 400 eV X-rays before and after cleaning using the sizing agent-coated carbon fiber obtained in Comparative Example 2 as in Example 39. , The height (cps) of the component of the binding energy (284.6 eV) attributed to C = C, and (b) the height (cps) of the component of the binding energy (286.1 eV) attributed to C—O. The ratio (a) / (b) was obtained. The results are shown in Table 6-1, and it was found that (II / I) was large and the sizing agent had no gradient structure.

(Comparative Example 16)
(A) CHx, C-C of C1s inner-shell spectrum by X-ray photoelectron spectroscopy using 400 eV X-rays before and after washing using the sizing agent-coated carbon fiber obtained in Comparative Example 5 as in Example 39. , The height (cps) of the component of the binding energy (284.6 eV) attributed to C = C, and (b) the height (cps) of the component of the binding energy (286.1 eV) attributed to C—O. The ratio (a) / (b) was obtained. The results are shown in Table 6-1, and it was found that (II / I) was small.

(Example 42)
2 g of the sizing agent-coated carbon fiber obtained in Example 27 was immersed in 50 ml of acetone and subjected to ultrasonic cleaning for 30 minutes three times. Subsequently, the substrate was immersed in 50 ml of methanol, subjected to ultrasonic cleaning for 30 minutes once and dried. Table 5 shows the amount of sizing agent adhesion remaining after washing.
Subsequently, the sizing agent surface of the sizing agent-coated carbon fiber before washing, and the sizing agent-coated carbon fiber sizing agent surface obtained by washing were assigned to (b) CO component by X-ray photoelectron spectroscopy at 400 eV. The peak height of the binding energy of 286.1 eV and the height (cps) of the component of the binding energy of 284.6 eV attributed to (a) CHx, C-C, C = C are obtained, and (I) before washing (A) / (b) on the sizing agent surface of the sizing agent-coated carbon fiber, (II) (a) / (b) on the sizing agent surface of the sizing agent-coated carbon fiber after washing. (I) and (II) / (I) were as shown in Table 6-2.

(Examples 43 to 44)
(A) CHx of the C1s core spectrum by X-ray photoelectron spectroscopy using 400 eV X-rays before and after cleaning using the sizing agent-coated carbon fibers obtained in Example 28 and Example 29 as in Example 42 , C—C, the height (cps) of the component of the bond energy (284.6 eV) attributed to C═C, and (b) the high of the component of the bond energy (286.1 eV) attributed to C—O. The ratio (a) / (b) to the thickness (cps) was obtained. The results are shown in Table 6-2.

(Comparative Example 17)
(A) CHx, C-C of C1s inner-shell spectrum by X-ray photoelectron spectroscopy using 400 eV X-rays before and after cleaning using the sizing agent-coated carbon fiber obtained in Comparative Example 10 as in Example 42 , The height (cps) of the component of the binding energy (284.6 eV) attributed to C = C, and (b) the height (cps) of the component of the binding energy (286.1 eV) attributed to C—O. The ratio (a) / (b) was obtained. The results are shown in Table 5-2, and it was found that (II / I) was large and no grading structure was obtained in the sizing agent.

(Comparative Example 18)
(A) CHx, C-C of C1s inner shell spectrum by X-ray photoelectron spectroscopy using 400 eV X-rays before and after cleaning using the sizing agent-coated carbon fiber obtained in Comparative Example 11 as in Example 42. , The height (cps) of the component of the binding energy (284.6 eV) attributed to C = C, and (b) the height (cps) of the component of the binding energy (286.1 eV) attributed to C—O. The ratio (a) / (b) was obtained. The results are shown in Table 6-2, and it was found that (II / I) was large and no grading structure was obtained in the sizing agent.

(Example 45)
10 g of the molding material obtained in Example 21 was placed in a beaker, and ultrasonic washing with 250 ml of formic acid was performed three times for 30 minutes, and finally ultrasonic washing with 250 ml of methanol was performed once for 30 minutes. Thereafter, the solvent was dried by drying at 80 ° C. for 30 minutes. (B) the peak height of the binding energy 286.1 eV attributed to the CO component and (a) CHx by X-ray photoelectron spectroscopy at 400 eV on the sizing agent-coated carbon fiber surface obtained by washing. The height (cps) of the component having a binding energy of 284.6 eV attributed to C-C and C = C was determined, and (a) / (b) was determined. The amount of sizing agent remaining and (a) / (b) remaining after washing were as shown in Table 7.

(Example 46)
Sizing agent-coated carbon fiber obtained by washing in the same manner as in Example 45 using the molding material obtained in Example 23 was assigned to (b) CO component by X-ray photoelectron spectroscopy at sizing agent surface 400 eV. The peak height of the binding energy 286.1 eV and (a) the height (cps) of the component of the binding energy 284.6 eV attributed to CHx, C—C, C = C is determined (a) / (b) Asked. The amount of sizing agent remaining and (a) / (b) remaining after washing were as shown in Table 7.

(Comparative Example 19)
Sizing agent-coated carbon fiber obtained by washing in the same manner as in Example 45 using the molding material obtained in Comparative Example 8 was assigned to (b) CO component by X-ray photoelectron spectroscopy at a sizing agent surface of 400 eV. The peak height of the binding energy 286.1 eV and (a) the height (cps) of the component of the binding energy 284.6 eV attributed to CHx, C—C, C = C is determined (a) / (b) Asked. As shown in Table 7, the sizing agent adhesion amount and (a) / (b) remaining after washing were large values.

(Comparative Example 20)
Sizing agent-coated carbon fiber obtained by washing in the same manner as in Example 45 using the molding material obtained in Comparative Example 9 was assigned to (b) CO component by X-ray photoelectron spectroscopy at a sizing agent surface of 400 eV. The peak height of the binding energy 286.1 eV and (a) the height (cps) of the component of the binding energy 284.6 eV attributed to CHx, C—C, C = C is determined (a) / (b) Asked. As shown in Table 7, the sizing agent adhesion amount and (a) / (b) remaining after washing were small values.

  Since the molding material, the method for producing the molding material and the carbon fiber reinforced composite material of the present invention are lightweight and have excellent strength and elastic modulus, they are aircraft members, spacecraft members, automobile members, ship members, civil engineering and building materials, and sporting goods. It can use suitably for many fields, such as.

Claims (19)

A molding material comprising a sizing agent-coated carbon fiber and a matrix resin in which a sizing agent is applied to at least carbon fiber,
The sizing agent contains at least the aromatic epoxy compound (B1) as the aliphatic epoxy compound (A) and the aromatic compound (B), and the sizing agent-coated carbon fiber has a surface of the sizing agent X Using AlKα ₁ and ₂ as the radiation source, the binding energy belonging to (a) CHx, C—C, C = C of the C _1s core spectrum measured at a photoelectron escape angle of 15 ° by X-ray photoelectron spectroscopy ( The ratio (a) / (b) between the height (cps) of the component of 284.6 eV) and the height (cps) of the component (286.1 eV) attributed to C—O is (b) 0.50-0.90,
The molding material is characterized in that the carbon fibers in the molding material are in the form of bundles or single fibers and are substantially two-dimensionally oriented.   2. The molding material according to claim 1, wherein the sizing agent-coated carbon fiber has a moisture content of 0.010 to 0.030 mass%.   The molding material according to claim 1 or 2, wherein a mass ratio of the aliphatic epoxy compound (A) and the aromatic epoxy compound (B1) in the sizing agent is 52/48 to 80/20. .   4. The aliphatic epoxy compound (A) is a polyether type polyepoxy compound and / or a polyol type polyepoxy compound having two or more epoxy groups in a molecule. The molding material described in one.   The aliphatic epoxy compound (A) is 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, glycerol, diglycerol, polyglycerol, trimethylolpropane, pentaerythritol, sorbitol, and arabitol, and epi Wherein the glycidyl ether type epoxy compound obtained by reaction of Rorohidorin molding material as claimed in claim 4.   The molding material according to any one of claims 1 to 5, wherein the aromatic epoxy compound (B1) is a bisphenol A type epoxy compound or a bisphenol F type epoxy compound. The sizing agent-coated carbon fiber is obtained by measuring the sizing agent-coated carbon fiber with a C1s inner-shell spectrum of (a) CHx, C- The height (cps) of the component of the bond energy (284.6 eV) attributed to C, C = C, and the height (cps) of the component of the bond energy (286.1 eV) attributed to (B) C—O. The ratio of (I) and (II) calculated | required from ratio (a) / (b) and (III) satisfy | fills the relationship of (III), It is any one of Claims 1-6 characterized by the above-mentioned. The molding material described in one.
(I) Value of (a) / (b) on the surface of the sizing agent-coated carbon fiber before sonication (II) Sizing agent adhesion by sonicating the sizing agent-coated carbon fiber in an acetone solvent (A) / (b) value (III) 0.50 ≦ (I) ≦ 0.90 and 0.60 <on the surface of the sizing agent-coated carbon fiber washed to 0.09 to 0.20% by mass (II) / (I) <1.0   The molding material is sonicated in a solvent that dissolves the matrix resin constituting the molding material, so that the amount of sizing agent applied to the surface of the sizing agent-coated carbon fiber is 0.09 to 0.20% by mass. The surface of the washed carbon fiber coated with the sizing agent is (a) CHx, C—C, C of the C1s inner shell spectrum measured at a photoelectron escape angle of 55 ° by X-ray photoelectron spectroscopy using 400 eV X-rays. = The ratio of the height (cps) of the component of the binding energy (284.6 eV) attributed to C and the height (cps) of the component (b) the binding energy (286.1 eV) attributed to C—O The molding material according to any one of claims 1 to 7, wherein (a) / (b) is 0.30 to 0.70.   The molding material according to claim 1, wherein an adhesion amount of the aliphatic epoxy compound (A) is 0.2 to 2.0% by mass.   The surface carboxyl group concentration COOH / C measured by chemical modification X-ray photoelectron spectroscopy of the carbon fiber is 0.003 to 0.015, and the surface hydroxyl group concentration COH / C is 0.001 to 0.050. The molding material according to any one of claims 1 to 9.   The molding material according to claim 1, wherein the matrix resin is a thermoplastic resin.   The thermoplastic resin is at least one selected from polyarylene sulfide resins, polyether ether ketone resins, polyphenylene ether resins, polyoxymethylene resins, polyester resins, polycarbonate resins, polystyrene resins and polyolefin resins. The molding material according to claim 11.   The molding material according to claim 11, wherein the thermoplastic resin is polyamide.   The molding material according to claim 1, wherein the matrix resin is a thermosetting resin.   The molding material according to claim 14, wherein the thermosetting resin is a radical polymerization resin.   The molding material according to any one of claims 1 to 15, wherein the molding material has a web shape, a nonwoven fabric shape, a felt shape, or a mat shape. A method for producing a molding material for producing the molding material according to any one of claims 1 to 16, comprising:
A processing step of processing carbon fiber into a web-like, non-woven, felt-like, or mat-like fabric;
For 100 parts by mass of the dough obtained in the processing step, 35 to 65% by mass of the aliphatic epoxy compound (A) and 35 to 60% by mass of the aromatic compound (B) with respect to the total amount of the sizing agent excluding the solvent; An application step of applying 0.1 to 10 parts by mass of a sizing agent containing at least
A compounding step in which 20 to 99% by mass of matrix resin is applied to 1 to 80% by mass of the sizing agent applied in the applying step,
The manufacturing method of the molding material characterized by including. A method for producing a molding material for producing the molding material according to any one of claims 1 to 16, comprising:
A sizing agent containing at least 35 to 65% by mass of an aliphatic epoxy compound (A) and 35 to 60% by mass of an aromatic compound (B) with respect to 100 parts by mass of carbon fiber, based on the total amount of the sizing agent excluding the solvent An application step of applying 0.1 to 10 parts by mass to obtain a sizing agent-coated carbon fiber;
A cutting step of cutting the sizing agent-coated carbon fiber obtained in the coating step into 1 to 50 mm;
A sizing agent-coated carbon fiber 1 to 80% by mass cut in the cutting step and a matrix resin 20 to 99% by mass are mixed and combined,
The manufacturing method of the molding material characterized by including.   A carbon fiber reinforced composite material obtained by molding the molding material according to any one of claims 1 to 16, or the molding material produced by the method according to claim 17 or 18.