JP2014145037A - 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 is formed from a sizing agent-coated carbon fiber in which a carbon fiber is coated with a sizing agent, and a thermoplastic 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 measured 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 arrayed substantially parallel to the axial direction, and the length is substantially the same as the length of the molding material.

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, it cannot be said that a sizing agent (for example, Patent Documents 20 to 23, etc.) in which two or more kinds are mixed is not sufficient for improving the physical properties of a molding material containing a sizing agent-coated carbon fiber and a thermoplastic resin. Was the actual situation. 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 carbon fiber coated with the surging agent and the thermoplastic resin, a highly adhesive component is disposed on the inner layer of the sizing layer, and a component having a 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, the interfacial adhesiveness with the carbon fiber is poor, and a further interfacial adhesiveness 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

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

  The present inventors have provided a columnar molding in which a sizing agent surface of a carbon fiber coated with a sizing agent in which a plurality of specific compounds are combined is composed of a sizing agent-coated carbon fiber having a specific chemical composition and a thermoplastic resin. It has been found that the above-mentioned object can be achieved in the material. That is, in the present invention, a known sizing agent can be used as the individual sizing agent itself, but it is important as a sizing method that the surface of the sizing agent has a specific chemical composition in a combination of specific compounds. And it can be said to be novel.

  In addition, the present inventors applied a sizing agent containing a specific proportion of the aliphatic epoxy compound (A) and the aromatic compound (B) to the carbon fiber, and applied the sizing agent to the molten thermoplastic resin. By passing a continuous carbon fiber and obtaining a strand and cutting the strand, a molding material with high interfacial adhesion between the carbon fiber and the thermoplastic resin can be obtained, and the molding material is molded. The present inventors have found that the properties of the carbon fiber reinforced composite material under wet condition are also good and have arrived at the present invention.

The present invention employs the following means in order to solve the above problems. That is, the present invention relates to a columnar molding material comprising a sizing agent-coated carbon fiber obtained by applying a sizing agent to carbon fiber and a thermoplastic resin, and the sizing agent includes an aliphatic epoxy compound (A) and an aromatic compound. The sizing agent-coated carbon fiber contains at least the aromatic epoxy compound (B1) as the group compound (B), and the sizing agent-coated carbon fiber uses AlKα _1,2 using the sizing agent surface as an X-ray source. (A) the height (cps) of the component of the bond energy (284.6 eV) belonging to (a) CHx, C—C, C = C of the C _1s core spectrum measured at a photoelectron escape angle of 15 ° by the method ( b) The ratio (a) / (b) of the height (cps) of the component of the binding energy (286.1 eV) attributed to C—O is 0.50 to 0.90, Carbon fiber in the material is arranged substantially parallel to the axial direction, and the length of the carbon fibers in the molding composition is characterized in that the substantially the same as the length of the molding material.

  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

  The molding material of the present invention is the sizing of the sizing agent-coated carbon fiber surface in the above invention by ultrasonically treating the molding material in a solvent that dissolves the thermoplastic resin constituting the molding material. The surface of the carbon fiber coated with the sizing agent that has been washed to 0.09 to 0.20% by mass of the agent is 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 in the inner shell spectrum, and (b) the binding energy attributed to C—O ( The ratio (a) / (b) of the height (cps) of the component of 286.1 eV) 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.

  Moreover, the molding material of this invention is 1-80 mass% of sizing agent application | coating carbon fibers by which the said sizing agent adheres 0.1-10.0 mass parts with respect to 100 mass parts of said carbon fibers in the said invention, And 20 to 99% by mass of a thermoplastic resin.

  In the molding material of the present invention, in the above invention, the structure Y mainly composed of the carbon fibers is a core structure, the structure X mainly composed of the thermoplastic resin is a sheath structure, It has a core-sheath structure in which the periphery is covered with the structure X.

  The molding material of the present invention is characterized in that, in the above invention, the length of the columnar molding material is 1 to 50 mm.

  The molding material of the present invention is characterized in that, in the above invention, the form is a long fiber pellet.

  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 impregnation aid (D) is contained in an amount of 0.1 to 100 parts by mass with respect to 100 parts by mass of the carbon fiber.

  Moreover, the molding material of the present invention is characterized in that, in the above invention, a part or all of the impregnation aid (D) is impregnated in carbon fiber.

  The present invention also relates to a method for producing a molding material for producing the molding material according to any one of the above, wherein the aliphatic epoxy compound (A) is 35 to 65 mass based on the total amount of the sizing agent excluding the solvent. % And a sizing agent containing at least 35 to 60% by mass of an aromatic compound (B), and a continuous sizing agent-coated carbon obtained by applying the molten thermoplastic resin in the coating process. It comprises a stranding step for impregnating fibers to obtain continuous strands, and a cutting step for cooling the strands obtained in the stranding step and then cutting to obtain a columnar molding material.

  Moreover, the manufacturing method of the molding material of this invention has the impregnation process which makes the said sizing agent application | coating carbon fiber impregnate the molten impregnation adjuvant (D) in the said invention before the said strand formation process. And

  The carbon fiber reinforced composite material of the present invention is characterized by molding the molding material according to any one of the above or the molding material produced by the method 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 thermoplastic resin as 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.

FIG. 1 is a perspective view showing an example of a molding material according to an embodiment of the present invention. FIG. 2 is a perspective view showing another example of the molding material according to the embodiment of the present invention.

  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 columnar molding material composed of carbon fiber and a sizing agent-coated carbon fiber in which carbon fiber is coated with a sizing agent, and 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 has a C _1s measured on the sizing agent surface at a photoelectron escape angle of 15 ° 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 in the inner shell spectrum and (b) the binding energy attributed to C—O (286) .1 eV) component height (cps) ratio (a) / (b) is 0.50 to 0.90, and the carbon fibers in the molding material are arranged substantially parallel to the axial direction. And the length of the carbon fibers in the molding material is a molding material, wherein said is substantially the same as the length of the molding material.

  According to the knowledge of the present inventors, such a range has a high interfacial adhesion between the carbon fiber and the thermoplastic resin, has excellent mechanical properties, and uses a highly hygroscopic resin as a 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 thermoplastic resin coated with a sizing agent composed only of an aromatic epoxy compound (B1) and not containing an aliphatic epoxy compound (A) 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 inclined 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 thermoplastic resin. . As a result, the interfacial adhesion between the carbon fiber and the thermoplastic resin can be enhanced, and the physical properties of the resulting carbon fiber reinforced composite material can be increased. 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 near the carbon fiber becomes low when wet, so that a decrease in physical properties is suppressed. 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 aliphatic epoxy compounds (A) are contained with respect to the sizing agent whole quantity except a solvent. When the aliphatic epoxy compound (A) is applied to the carbon fiber at a ratio of 35% by mass or more, the interfacial adhesion with the thermoplastic 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 content is 65% by mass or less, and the interaction between the sizing agent and the thermoplastic resin is increased, and thereby the carbon fiber reinforced composite. The physical properties of the 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 less.

  It is preferable that 35-60 mass% of aromatic compounds (B) are contained with respect to the sizing agent whole quantity except a solvent. 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 thermoplastic resin becomes stronger and carbon The moisture content in the vicinity of the carbon fiber in the fiber reinforced composite material 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 less.

  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 tensile 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 thermoplastic 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 thermoplastic resin, which is preferable because the adhesiveness is further improved. 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 thermoplastic 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 consisting 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 thermoplastic resin, a so-called interface layer in the vicinity of the carbon fiber is affected by the carbon fiber or the sizing agent and has characteristics different from those of the thermoplastic resin. There is a case. 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 thermoplastic resin is improved, the tensile strength of the carbon fiber reinforced composite material, etc. Improved mechanical properties. In particular, when a highly hydrophobic resin containing a large amount of aromatic rings or hydrocarbons is used as the thermoplastic resin, the interaction with the aromatic compound (B) contained in the sizing agent is high and the adhesion is improved. preferable. 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 a polyarylene sulfide resin, it does not disappear due to thermal decomposition, and oxygen on the surface of the original carbon fiber. It is possible to maintain the function of the reaction with the contained functional group and the interaction with the thermoplastic resin. In addition, because the hydrophobicity is improved by the aromatic ring, the moisture content in the vicinity of the carbon fiber can be lowered. Therefore, even when a highly hygroscopic thermoplastic resin is used, the physical properties of the carbon fiber composite material under wet conditions Since a fall is suppressed, it 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. Use of an epoxy group or a functional group other than an epoxy group is preferable because it can interact with a thermoplastic 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 The epoxy group or other functional group can form an interaction such as a covalent bond or a hydrogen bond with the thermoplastic resin, and the interfacial adhesion with the thermoplastic 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 a high density, and the interfacial adhesion to carbon fiber, aliphatic epoxy compound (A) or thermoplastic 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 as a result, the interaction with the carbon fiber, the aliphatic epoxy compound (A), and the thermoplastic resin is strong, and the interfacial adhesiveness. It is preferable that the mechanical properties such as the tensile strength of the carbon fiber reinforced composite material are improved and the mechanical properties when wet are improved because the ratio of the aromatic ring 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 imparting convergence or flexibility to carbon fiber coated with sizing agent to improve handling, scratch resistance and fluff resistance, A sizing agent that improves the impregnation property of the plastic 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 reinforced material according to the present invention.

  The sizing agent used in the present invention contains, in addition to the aliphatic epoxy compound (A) and the aromatic epoxy compound (B1), an ester compound (C) having no epoxy group in the molecule of 2 to 35% by mass. Can do. 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 the adhesiveness for the purpose of improving the adhesiveness of the carbon fiber and the epoxy compound in a sizing agent component, and improving the interface adhesiveness of carbon fiber and a thermoplastic 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 thermoplasticity. It is preferable because the interfacial adhesion of the resin 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 the atmosphere For each sample, the image obtained by observing one single fiber at a time, approximating the roundness of the fiber cross section with a cubic surface, and the entire image obtained As above, it is preferable to calculate the surface roughness (Ra) of the carbon fiber, determine 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 thermoplastic 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 to 20 mm, spread and arranged on a copper sample support base, and then AlKα ₁ and ₂ were used as an X-ray source. 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, the impregnation property of the thermoplastic resin between the carbon fibers becomes good.

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

  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 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 interface between the carbon fiber and the thermoplastic resin This is preferable because the adhesiveness is sufficient. 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 thermoplastic resin is improved. This is preferable because it is sufficient.

  The heat treatment can also be performed by microwave irradiation and / or infrared irradiation. When carbon fiber coated with a sizing agent by microwave irradiation and / or infrared irradiation is heated, the microwave penetrates into the carbon fiber and is absorbed, so that the desired carbon fiber is heated in a short time. Can be heated to 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 thermoplastic resin is high. Become. As a result, the interfacial adhesion between the carbon fiber and the thermoplastic resin is excellent, and the properties of the resulting carbon fiber reinforced composite material are improved. In addition, when the carbon fiber was used, it was also found that the mechanical properties of the obtained carbon fiber reinforced composite material under wet conditions are good even when a highly hygroscopic thermoplastic resin is used. It is.

  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), the adhesion with the matrix resin is excellent, the interaction with the thermoplastic resin used for the matrix resin is high, and the heat of good physical properties. A plastic resin composition is 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 is attached in an amount of 0.1 part by mass or more, the carbon fiber coated with the sizing agent can withstand friction caused by a metal guide that passes therethrough and the generation of fluff is suppressed. The quality of the carbon fiber sheet is excellent. On the other hand, when the adhesion amount of the sizing agent is 10.0 parts by mass or less, the thermoplastic resin is impregnated into the carbon fiber without being obstructed by the sizing agent film around the carbon fiber to which the sizing agent is applied. The formation of voids in the carbon fiber reinforced composite material is suppressed, the quality is excellent, and at the same time, the mechanical properties are excellent, which is preferable.

  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 is determined by measuring the change in mass, and is defined as the amount of adhesion of the sizing agent (part by mass).

  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. It is preferable because the interfacial adhesion between the carbon fiber coated with the sizing agent and the thermoplastic 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, it is preferable that the adhesion amount of the aliphatic epoxy compound (A) to carbon fiber is the range of 0.05-5.0 mass parts with respect to 100 mass parts of carbon fibers, More preferably, it is 0. .2 to 2.0 parts by mass. 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 adhesiveness between the carbon fiber and the thermoplastic resin in which the sizing agent is applied to the carbon fiber surface with the aliphatic epoxy compound (A) It is preferable because it improves.

  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 surface of the carbon fiber decreases when the carbon fiber coated with the sizing agent of the present invention is mixed with the thermoplastic resin. It is preferable because the interaction with the thermoplastic 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% was set, 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, and more preferably 0.022% by mass or less. Moreover, since the uniform coating property of the sizing material apply | coated to carbon fiber improves because the minimum of a moisture content is 0.010 mass% or more, it is preferable. 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.

  Next, the molding material and the carbon fiber reinforced composite material according to the present invention will be described. The molding material concerning this invention is comprised from the above-mentioned sizing agent application | coating carbon fiber and a thermoplastic resin. As shown in FIG. 1, the molding material 1 of the present invention has a cylindrical shape, and a plurality of carbon fibers 2 are arranged substantially parallel to the axial direction of the cylinder, and the periphery of the carbon fibers is covered with a thermoplastic resin 3. It has been broken. That is, the carbon fibers 2 mainly constitute a cylindrical core structure, and the thermoplastic resin 3 constitutes a main component of a sheath structure that covers the core structure made of the carbon fibers 2. If the molding material 1 of this invention comprises a core-sheath structure with the carbon fiber 2 and the thermoplastic resin 3, it does not ask | require the shape, such as columnar shape, prismatic column shape, elliptical column shape. In the present specification, “arranged substantially in parallel” means a state in which the long axis of the carbon fiber and the long axis of the molding material 1 are oriented in the same direction. The angle deviation is preferably 20 ° or less, more preferably 10 ° or less, and further preferably 5 ° or less.

  Moreover, in the molding material 1 of this invention, it is preferable that it is a long fiber pellet in which the length of carbon fiber and the length L of a molding material are substantially the same. In the present specification, “substantially the same length” means that in the pellet-shaped molding material 1, the carbon fibers 2 are cut in the middle of the pellet, or significantly longer than the total length of the molding material 1. It means that the short carbon fiber 2 is not substantially contained. In particular, it is not necessary to limit the amount of carbon fibers shorter than the length L of the molding material 1, but the content of carbon fibers having a length of 50% or less of the length L of the molding material 1 is 30% by mass or less. In some cases, it is evaluated that a carbon fiber bundle significantly shorter than the entire length of the molding material 1 is not substantially contained. Furthermore, the content of carbon fibers having a length of 50% or less of the total length of the molding material 1 is preferably 20% by mass or less. The total length of the molding material 1 is the length L in the carbon fiber orientation direction in the molding material 1. Since the carbon fiber 2 has a length equivalent to that of the molding material 1, the carbon fiber length in the molded product can be increased, so that excellent mechanical properties can be obtained.

  The molding material of the present invention is preferably used after being cut to a length in the range of 1 to 50 mm. By adjusting to the above length, the fluidity and handleability during molding can be sufficiently enhanced. Further, the molding material of the present invention can be used depending on the molding method even if it is continuous or long. For example, as a thermoplastic yarn prepreg, it can be wound around a mandrel while heating to obtain a roll-shaped molded product.

  Examples of the thermoplastic resin used in the molding material of the present invention include “polyesters such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polytrimethylene terephthalate (PTT), polyethylene naphthalate (PEN), and liquid crystal polyester. Polyethylene resins such as polyethylene (PE), polypropylene (PP), polybutylene, acid-modified polyethylene (m-PE), acid-modified polypropylene (m-PP), acid-modified polybutylene; polyoxymethylene (POM), polyamide Polyarylene sulfide resins such as (PA) and polyphenylene sulfide (PPS); polyketone (PK), polyetherketone (PEK), polyetheretherketone (PEEK), polyetherketoneketone (PEKK) Polyether nitrile (PEN); Fluororesin such as polytetrafluoroethylene; Crystalline resin such as “Liquid Crystal Polymer (LCP)”, Polystyrene such as “Polystyrene (PS), Acrylonitrile Styrene (AS), Acrylonitrile Butadiene Styrene (ABS) Resin, 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) ", etc .; phenol resins, phenoxy resins, polystyrene elastomers, polyolefin elastomers, polyurethanes Elastomer, polyester elastomer, polyamide elastomer, polybutadiene elastomer, polyisoprene elastomer, various thermoplastic elastomers such as fluororesin and acrylonitrile elastomer, at least one selected from these copolymers and modified products A thermoplastic resin is preferably used. In addition, as a thermoplastic resin, the thermoplastic resin composition containing multiple types of these thermoplastic resins may be used in the range which does not impair the objective of this invention.

  Moreover, what provided the impregnation adjuvant between the carbon fiber 2 and the thermoplastic resin 3 as a molding material of this invention can be used conveniently. FIG. 2 is a perspective view of a molding material 1A according to the present invention. In the molding material 1A, a plurality of carbon fibers 2 are arranged substantially parallel to the axial direction of the cylinder, the periphery of the carbon fibers 2 is covered with the impregnation aid 4, and the periphery of the impregnation aid 4 is covered with the thermoplastic resin 3. The structure to cover is made. In order to improve the mechanical properties of a molded product obtained by molding a molding material, it is generally preferable to use a high molecular weight thermoplastic resin. However, a high molecular weight thermoplastic resin has a high melt viscosity and is a carbon fiber. There is a problem that it is difficult to impregnate the bundle. On the other hand, in order to improve the impregnation property of the thermoplastic resin into the carbon fiber bundle, it is preferable to use a low molecular weight thermoplastic resin having a low melt viscosity, but a molded article using the low molecular weight thermoplastic resin. Will greatly reduce the mechanical properties.

  Therefore, after impregnating a bundle of carbon fibers with a relatively low molecular weight resin (prepolymer) as an impregnation aid 4, a mechanical property is obtained by using a relatively high molecular weight thermoplastic resin 3 as a matrix resin. It is possible to produce an excellent molding material with high productivity.

Hereinafter, the suitable form about the molding material which uses an impregnation adjuvant is demonstrated.
The impregnation aid (D) is preferably 0.1 to 100 parts by mass with respect to 100 parts by mass of the carbon fiber. More preferably, it is 10-70 mass parts, More preferably, it is 15-30 mass parts. When the impregnation aid (D) is 0.1 to 100 parts by mass with respect to 100 parts by mass of the carbon fiber, a carbon fiber reinforced composite material having high mechanical properties can be produced with high productivity.

  When the polyarylene sulfide resin is used as the thermoplastic resin, the impregnation aid (D) has a weight average molecular weight of 10,000 or more and a dispersity represented by weight average molecular weight / number average molecular weight of 2.5. It is preferable to use the following polyarylene sulfide [d] (hereinafter abbreviated as PAS).

  The molecular weight of PAS, which is an impregnation aid, is 10,000 or more, preferably 15,000 or more, more preferably 18,000 or more in terms of mass average molecular weight. When the mass average molecular weight is less than 10,000, a low molecular weight component may cause a thermal decomposition reaction during molding at a higher temperature (for example, 360 ° C.), generating decomposition gas and causing environmental pollution around the molding equipment. . Although there is no restriction | limiting in particular in the upper limit of a mass mean molecular weight, 1,000,000 or less can be illustrated as a preferable range, More preferably, it is 500,000 or less, More preferably, it is 200,000 or less, High impregnation property in this range As well as moldability can be obtained.

  When a polyamide resin is used as the thermoplastic resin, it is preferable to use a phenolic polymer [e] as the impregnation aid (D).

  Examples of the phenolic polymer [e] used as the impregnation aid include, for example, a condensation reaction of phenol or a phenol substituent derivative (precursor a) and a hydrocarbon having two double bonds (precursor b). The phenolic polymer obtained is mentioned.

  As said precursor a, what has 1-3 substituents chosen from an alkyl group, a halogen atom, and a hydroxyl group on the benzene ring of phenol is used preferably. Specific examples include cresol, xylenol, ethylphenol, butylphenol, t-butylphenol, nonylphenol, 3,4,5-trimethylphenol, chlorophenol, bromophenol, chlorocresol, hydroquinone, resorcinol, orcinol, These may be used alone or in combination of two or more. In particular, phenol and cresol are preferably used.

  Examples of the precursor b include aliphatic hydrocarbons such as butadiene, isoprene, pentadiene and hexadiene, cyclohexadiene, vinylcyclohexene, cycloheptadiene, cyclooctadiene, 2,5-norbornadiene, tetrahydroindene, dicyclopentadiene, monocyclic ring Alicyclic hydrocarbons such as monoterpenes (dipentene, limonene, terpinolene, terpinene, ferrandylene), bicyclic sesquiterpenes (kadinene, serinene, caryophyllene), etc., which are used alone or in combination of two or more May be. In particular, monocyclic monoterpenes and dicyclopentadiene are preferably used.

  When a polyolefin resin is used as the thermoplastic resin, it is preferable to use a terpene resin [f] as the impregnation aid (D).

  As terpene resin [f] used as impregnation aid (D), in the presence of Friedel-Crafts type catalyst in organic solvent, terpene monomer alone or terpene monomer and aromatic monomer etc. Examples thereof include a resin made of a polymer obtained by coalescence.

  The terpene resin [f] is a thermoplastic polymer having a melt viscosity lower than that of the polyolefin resin. In the molding process such as injection molding or press molding, the viscosity of the resin composition is lowered to improve the moldability. It is possible to improve. At this time, since the terpene resin [f] has good compatibility with the polyolefin resin, the moldability can be effectively improved.

  As the terpene monomer, α-pinene, β-pinene, dipentene, d-limonene, myrcene, alloocimene, ocimene, α-ferrandrene, α-terpinene, γ-terpinene, terpinolene, 1,8-cineole, 1, Examples include monocyclic monoterpenes such as 4-cineole, α-terpineol, β-terpineol, γ-terpineol, sabinene, paramentadienes, and carenes. Examples of the aromatic monomer include styrene and α-methylstyrene.

  Of these, α-pinene, β-pinene, dipentene, and d-limonene are preferable because of their good compatibility with polyolefin resins, and a homopolymer of the compound is more preferable. A hydrogenated terpene resin obtained by hydrogenation treatment of the terpene resin is preferable because the compatibility with the polyolefin resin is improved.

  Further, when a polyolefin resin is used as the thermoplastic resin, as the impregnation aid (D) component, the first propylene resin [g] and the second propylene resin [h] having an acyl group in the side chain are used. It is preferred to use a mixture.

  Examples of the first propylene-based resin [g] used as the impregnation aid (D) include a propylene homopolymer or a copolymer of propylene and at least one α-olefin, conjugated diene, non-conjugated diene, or the like. It is done.

  Examples of the monomer repeating unit constituting the α-olefin include ethylene, 1-butene, 3-methyl-1-butene, 4-methyl-1-pentene, 3-methyl-1-pentene, 4-methyl- 2-12 carbon atoms excluding propylene such as 1-hexene, 4,4 dimethyl-1-hexene, 1-nonene, 1-octene, 1-heptene, 1-hexene, 1-decene, 1-undecene and 1-dodecene Examples of the monomer repeating unit constituting the α-olefin, conjugated diene, and non-conjugated diene include butadiene, ethylidene norbornene, dicyclopentadiene, 1,5-hexadiene, and the like. One type or two or more types can be selected.

  Examples of the skeleton structure of the first propylene resin [g] include a propylene homopolymer, one or two or more random or block copolymers of propylene and the other monomers, or other heat. Examples thereof include a copolymer with a plastic monomer. For example, polypropylene, ethylene / propylene copolymer, propylene / 1-butene copolymer, ethylene / propylene / 1-butene copolymer, and the like are preferable.

  Examples of the raw material for the second propylene resin [h] include polypropylene, ethylene / propylene copolymer, propylene / 1-butene copolymer, and ethylene / propylene / 1-butene copolymer. -Monomers of olefins alone or in copolymers with two or more, neutralized or non-neutralized monomers with acyl groups, and / or saponified or unsaponified carboxylic acids A monomer having an ester can be obtained by graft polymerization. The monomer repeating unit and the skeleton structure of the copolymer of propylene and α-olefin alone or in combination of two or more can be selected in the same manner as the first propylene resin [g].

  Here, as a monomer having an acyl group which is neutralized or not neutralized, and a monomer having a carboxylic acid ester group which is saponified or not saponified, for example, ethylene Examples thereof include unsaturated carboxylic acids and anhydrides thereof, and esters thereof, and compounds having unsaturated vinyl groups other than olefins.

  Examples of the ethylenically unsaturated carboxylic acid include (meth) acrylic acid, maleic acid, fumaric acid, tetrahydrophthalic acid, itaconic acid, citraconic acid, crotonic acid, isocrotonic acid, and the like, and its anhydride includes nadic acid ( Registered trademark) (endocis-bicyclo [2.2.1] hept-5-ene-2,3-dicarboxylic acid), maleic anhydride, citraconic anhydride, and the like.

  In the molding materials 1 and 1A according to the present invention, 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. The at least one kind of thermoplastic resin is preferable because the interaction with the aromatic compound (B) is large, and the strong interaction between the sizing agent and the thermoplastic resin can form a strong interface.

  In addition, 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 addition, as a thermoplastic resin, the thermoplastic resin composition containing multiple types of these thermoplastic resins may be used in the range which does not impair the objective of this invention.

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.

  The molding material of the present invention is subjected to ultrasonic treatment in a solvent that dissolves the thermoplastic resin constituting the molding material, so that the amount of sizing agent applied to the sizing agent-coated carbon fiber surface is 0.09 to 0.20. The surface of the carbon fiber coated with the sizing agent that has been washed to mass% is (a) CHx, C- of the C1s core spectrum measured at a photoemission 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 C, C = C, and the height (cps) of the component of the bond energy (286.1 eV) attributed to (B) C—O. ) Ratio (a) / (b) is preferably 0.30 to 0.70. It is preferable that (a) / (b) is 0.30 or more because the interaction between the thermoplastic resin and the sizing agent is improved. More preferably, it is 0.35 or more. Moreover, since (a) / (b) is 0.70 or less, since the adhesiveness of carbon fiber and a sizing agent improves, it is preferable because the physical property of a composite becomes favorable. More preferably, it is 0.60 or less. The solvent that elutes the thermoplastic resin and the sizing agent of the molding material is not limited as long as the thermoplastic resin can be dissolved and the amount of the sizing agent after washing falls within the above range. For example, when a polyamide resin is used as the thermoplastic resin, formic acid is preferable, and when a polycarbonate resin is used, dichloromethane is preferably used.

  Next, the preferable aspect for manufacturing the molding material and carbon fiber reinforced composite material of this invention is demonstrated.

  In the manufacturing method of the molding material in this invention, the sizing which contains at least 35-65 mass% of aliphatic epoxy compounds (A) and 35-60 mass% of aromatic compounds (B) with respect to the sizing agent whole quantity except a solvent. Coating step for applying the agent to continuous carbon fiber, sizing agent-coated carbon fiber impregnated in molten thermoplastic resin, stranding step for obtaining continuous strands, and cooling the strands, then cutting and columnar It is preferable to have the cutting process of obtaining the molding material.

The carbon fiber to which the sizing agent is applied can be obtained by an application process in which the sizing agent is applied to the carbon fiber. The sizing agent-coated carbon fiber obtained in the first step of the present invention comprises (a) CHx, C-C, C _1s inner-shell spectrum measured on the sizing agent surface by X-ray photoelectron spectroscopy at a photoelectron escape angle of 15 °. The ratio between the height (cps) of the component of the binding energy (284.6 eV) attributed to C = C and the height (cps) of the component of the binding energy (286.1 eV) attributed to (B) C—O (A) / (b) is 0.50-0.90.

  In the present invention, the method of impregnating the carbon fiber coated with the sizing agent with the thermoplastic resin is not limited. For example, the drawing is performed by impregnating the carbon fiber with the thermoplastic resin while drawing the carbon fiber coated with the sizing agent. A molding method (a pultrusion method) is exemplified. In the pultrusion method, a resin additive is added to the thermoplastic resin as necessary, and the continuous carbon fiber is drawn through the crosshead die while the thermoplastic resin is supplied from the extruder to the crosshead die in a molten state. The fiber is impregnated with a thermoplastic resin, and the continuous carbon fiber impregnated with the molten resin is heated and cooled. The cooled strand is cut at right angles to the drawing direction to obtain the molding material 1. In the molding material 1, carbon fibers are arranged in parallel in the length direction with the same length. In pultrusion, basically, a continuous carbon fiber bundle is drawn and the thermoplastic resin is impregnated. While the carbon fiber bundle is passed through the cross head, the thermoplastic resin is supplied to the cross head from an extruder or the like. In addition to the impregnation method, the impregnation bath containing a thermoplastic resin emulsion, suspension or solution is impregnated through the carbon fiber bundle, or the powder of the thermoplastic resin is sprayed on the carbon fiber bundle. It is also possible to use a method in which a carbon fiber bundle is passed through the tank, the thermoplastic resin powder is adhered to the carbon fiber, and then the thermoplastic resin is melted and impregnated. Particularly preferred is the crosshead method. Further, the resin impregnation operation in these pultrusion moldings is generally performed in one stage, but this may be divided into two or more stages, and the impregnation method may be different.

  The pultrusion method is preferable because carbon fibers can be uniformly arranged and a carbon fiber reinforced composite material having excellent mechanical properties can be obtained.

  Further, the molding material having the impregnation aid (D) is obtained by impregnating the impregnation aid (D) into the sizing agent-coated carbon fiber, and then the sizing agent-coated carbon fiber impregnated with the impregnation aid (D). It is preferable to impregnate. For example, it is manufactured by coating with a thermoplastic resin by the above-described pultrusion method (pultrusion method).

  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.

  The molding material of the present invention is preferably used in the form of long fiber pellets. Examples of the molding method of the molding material according to the present invention include injection molding (such as injection compression molding, gas assist injection molding and insert molding), extrusion molding, and press molding. Among these, injection molding is preferably used from the viewpoint of productivity. A carbon fiber reinforced composite material can be obtained by these molding methods.

  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. Sizing agent-coated carbon fibers were cut to 20 mm, spread and arranged on a copper sample support, and AlKα ₁ and ₂ were used as an X-ray source, and the inside of the sample chamber was kept at 1 × 10 ⁻⁸ Torr, photoemission Measurements were made at an angle of 15 °. 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 _286.1EV, 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 of 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 injection molded product From an injection molded product obtained by injection molding a molding material containing sizing agent-coated carbon fiber and thermoplastic resin, length 130 ± 1 mm, width 25 ± 0.2 mm A bending strength test piece was cut out. 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 an injection molded product About a molded product obtained by using polyamide as a thermoplastic resin, the test piece is immersed in water at 25 ° C. to give water to the test piece. Bending characteristics were evaluated when water was absorbed by 5%. As a result, with respect to the bending strength obtained in (8), the rate of decrease was 60% or less as a preferable range, and when it was greater than 60%, the rate of decrease was determined as 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

(Reference Example 1)
<Preparation of polyphenylene sulfide prepolymer: D-1>
In a 1000 liter autoclave equipped with a stirrer, 47.5% sodium hydrosulfide 118 kg (1000 mol), 96% sodium hydroxide 42.3 kg (1014 mol), N-methyl-2-pyrrolidone (hereinafter sometimes abbreviated as NMP) 163 kg (1646 mol), sodium acetate 24.6 kg (300 mol), and 150 kg of ion-exchanged water are gradually heated to 240 ° C. over 3 hours while passing nitrogen at normal pressure, and passed through a rectifying column. After distilling 211 kg of water and 4 kg of NMP, the reaction vessel was cooled to 160 ° C. In addition, 0.02 mol of hydrogen sulfide per 1 mol of the sulfur component charged during this liquid removal operation was scattered out of the system.
Next, 147 kg (1004 mol) of p-dichlorobenzene and 129 kg (1300 mol) of NMP were added, and the reaction vessel was sealed under nitrogen gas. While stirring at 240 rpm, the temperature was raised to 270 ° C. at a rate of 0.6 ° C./min and held at this temperature for 140 minutes. Water was cooled to 250 ° C. at a rate of 1.3 ° C./min while 18 kg (1000 mol) of water was injected over 15 minutes. Thereafter, it was cooled to 220 ° C. at a rate of 0.4 ° C./min, and then rapidly cooled to near room temperature to obtain slurry (E). This slurry (E) was diluted with 376 kg of NMP to obtain a slurry (F). 14.3 kg of slurry (F) heated to 80 ° C. was filtered off with a sieve (80 mesh, opening 0.175 mm) to obtain 10 kg of crude PPS resin and slurry (G). The slurry (G) was charged into a rotary evaporator, replaced with nitrogen, treated at 100 to 160 ° C. under reduced pressure for 1.5 hours, and then treated at 160 ° C. for 1 hour in a vacuum dryer. The amount of NMP in the obtained solid was 3% by mass.

After adding 12 kg of ion-exchanged water (1.2 times the amount of slurry (G)) to this solid, it was stirred at 70 ° C. for 30 minutes to make a slurry again. This slurry was subjected to suction filtration with a glass filter having an opening of 10 to 16 μm. 12 kg of ion-exchanged water was added to the obtained white cake, and the mixture was stirred again at 70 ° C. for 30 minutes to form a slurry again. The above operation was repeated until the polyphenylene sulfide prepolymer reached a predetermined amount.
4 g of the obtained polyphenylene sulfide oligomer was collected and subjected to Soxhlet extraction with 120 g of chloroform for 3 hours. Chloroform was distilled off from the obtained extract, and 20 g of chloroform was again added to the resulting solid, which was dissolved at room temperature to obtain a slurry-like mixture. This was slowly added dropwise to 250 g of methanol while stirring, and the precipitate was suction filtered through a glass filter having an opening of 10 to 16 μm, and the resulting white cake was vacuum dried at 70 ° C. for 3 hours to obtain a white powder.
The white powder had a weight average molecular weight of 900. The absorption spectrum in the infrared spectroscopic analysis of this white powder revealed that the white powder was polyphenylene sulfide (PAS). Moreover, as a result of analyzing the thermal characteristics of this white powder using a differential scanning calorimeter (temperature increase rate 40 ° C./min), it shows a broad endotherm at about 200 to 260 ° C., and the peak temperature is 215 ° C. I understood it.
Moreover, this white powder was obtained from cyclic polyphenylene sulfide having 4 to 11 repeating units and cyclic polyphenylene sulfide having 2 to 11 repeating units based on mass spectral analysis of components separated by high performance liquid chromatography and molecular weight information by MALDI-TOF-MS. It was a mixture of chain polyphenylene sulfide, and the mass ratio of cyclic polyphenylene sulfide to linear polyphenylene sulfide was found to be 9: 1.

(Reference Example 2)
<Adjustment of propylene-based resin mixture PP: D-3>
As the first propylene-based resin (g), propylene / butene / ethylene copolymer (g-1) (constituent unit derived from propylene (hereinafter also referred to as “C3”) = 66 mol%, Mw = 90,000. ) 91 parts by mass, as a raw material for the second propylene resin (h), maleic anhydride-modified propylene / ethylene copolymer (C3 = 98 mol%, Mw = 25,000, acid content = 0.81 mmol equivalent) ) 9 parts by mass, 3 parts by mass of potassium oleate were mixed as a surfactant. This mixture was supplied at a rate of 3000 g / hour from the hopper of a twin screw extruder (Ikegai Iron Works, PCM-30, L / D = 40), and from the supply port provided in the vent portion of the extruder, A 20% aqueous potassium hydroxide solution was continuously supplied at a rate of 90 g / hour and continuously extruded at a heating temperature of 210 ° C. The extruded resin mixture was cooled to 110 ° C. with a jacketed static mixer installed at the extruder mouth, and further poured into warm water at 80 ° C. to obtain an emulsion. The obtained emulsion had a solid content concentration of 45%.
The maleic anhydride-modified propylene / ethylene copolymer (C3 = 98 mol%, Mw = 25,000, acid content = 0.81 mmol equivalent) is 96 parts by mass of propylene / ethylene copolymer, maleic anhydride. It was obtained by mixing 4 parts by mass and 0.4 parts by mass of perhexi 25B (manufactured by NOF Corporation) as a polymerization initiator and performing modification at a heating temperature of 160 ° C. for 2 hours.

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

Thermoplastic resin polyarylene sulfide (PPS) resin pellets: “Torelina (registered trademark)” A900 (manufactured by Toray Industries, Inc.)
Polyamide 6 (PA6) resin pellet: “Amilan (registered trademark)” CM1001 (manufactured by Toray Industries, Inc.)
Polypropylene (PP) resin pellets (polyolefin resin): a mixture of unmodified PP resin pellets and acid-modified PP resin pellets, unmodified PP resin pellets: “Prime Polypro (registered trademark)” J830HV (manufactured by Prime Polymer Co., Ltd.) 50 Mass parts, acid-modified PP resin pellets: “Admer (registered trademark)” QE800 (manufactured by Mitsui Chemicals) 50 mass parts Polycarbonate (PC) resin pellets: “Lexan (registered trademark)” 141R (SABIC)

-Component (D): D-1 to D-4
D-1: Polyphenylene sulfide prepolymer prepared in Reference Example D-2: Terpene resin (resin composed of polymer polymerized using α-pinene and β-pinene as main components, YS resin manufactured by Yasuhara Chemical Co., Ltd.) PX1250 resin)
D-3: Propylene-based resin mixture prepared in Reference Example D-4: Terpene phenol polymer (monocyclic monoterpene phenol and phenol adduct, YP902 manufactured by Yashara Chemical Co., Ltd.)

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. This was designated as carbon fiber A.
-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. 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. 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, the epoxy equivalent of the sizing agent applied to the carbon fiber, the moisture content of the carbon fiber applied with the sizing agent, the X-ray photoelectron spectroscopy measurement of the surface of the sizing agent, and the proportion of the eluted aliphatic epoxy compound were measured. The results are summarized in Table 1-1. 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: Step of producing long fiber pellets A cross-head die processed into a wave shape that allows continuous sizing agent-coated carbon fibers to pass through was attached to the tip of a single screw extruder. Next, while drawing continuous sizing agent-coated carbon fibers through a crosshead die at a speed of 5 m / min, PPS resin pellets are fed from the extruder to the crosshead die in a molten state, and continuous sizing agent-coated carbon fibers Impregnated with PPS resin, and after cooling, cut to 7 mm perpendicular to the drawing direction, the carbon fibers are arranged substantially parallel to the axial direction, and the length of the carbon fibers is substantially the same as the length of the molding material A long fiber pellet (Form A) was obtained. The extruder was sufficiently kneaded at a barrel temperature of 320 ° C. and a rotation speed of 150 rpm, and further deaerated from a downstream vacuum vent. The supply of PPS resin pellets was adjusted so that the sizing agent-coated carbon fiber was 80 parts by mass with respect to 20 parts by mass.
-Step IV: injection molding process Using the J350EIII type injection molding machine manufactured by Nippon Steel Works, the long fiber pellets obtained at the previous step were characterized at a cylinder temperature of 330 ° C and a mold temperature of 100 ° C. A test specimen for evaluation was molded. The obtained test piece was subjected to a characteristic evaluation test after being left in a constant temperature and humidity chamber adjusted to a temperature of 23 ° C. and 50% RH for 24 hours. 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 284 MPa and the mechanical properties were sufficiently high.

(Examples 2 to 10)
-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), (B1) Kinds and amounts of components, (C1), except that the amounts of other components were used as shown in Table 1-1. A carbon fiber coated with a sizing agent was obtained in the same manner as in Example 1. 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 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.
-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. The results are summarized in Table 1-1. As a result, it was found that the bending strength was 274 to 291 MPa, and the mechanical properties were sufficiently high.

(Example 11)
-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 The sizing agent is adjusted in the same manner as in Step II of Example 1, and the carbon fiber coated with the sizing agent in the same manner as in Example 1 is prepared. Obtained. 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.
-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. The results are summarized in Table 1-1. As a result, it was found that the bending strength was 283 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. This was designated as carbon fiber B.
-Step II: Step of attaching sizing agent to carbon fiber (A), (B1) Kinds and amounts of components, (C1), except that the amounts of other components were used as shown in Table 1-1. A carbon fiber coated with a sizing agent was obtained in the same manner as in Example 1. 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 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 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. This was designated as carbon fiber C.
-Step II: Step of attaching sizing agent to carbon fiber (A), (B1) Kinds and amounts of components, (C1), except that the amounts of other components were used as shown in Table 1-1. A carbon fiber coated with a sizing agent was obtained in the same manner as in Example 1. 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 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 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 applied as a dimethylformamide solution. Obtained the carbon fiber which apply | coated the sizing agent by the method similar to Example 1. FIG. 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 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 high.

(Comparative Example 1)
-Step I: Step of producing carbon fiber as a raw material The same as in Example 1.
-Step II: Step of attaching sizing agent to carbon fiber (A) Not using component (B1) Implementing except that component type and amount, and other component amounts were used as shown in Table 1-2 A carbon fiber coated 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 2)
-Step I: Step of producing carbon fiber as a raw material The same as in Example 1.
-Step II: Step of attaching sizing agent to carbon fiber (B1) The same method as in Example 1 except that component (A) is not used and the type and amount of component (A) are used as shown in Table 1-2. To obtain a carbon fiber coated with a sizing agent. 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 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 1-2 and the mechanical properties were slightly low.

(Comparative Example 3)
-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), (B1) Kinds and amounts of components, (C1), except that the amounts of other components were used as shown in Table 1-2. A carbon fiber coated 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 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 1-2 and the mechanical properties were insufficient.

(Comparative Example 4)
-Step I: Step of producing carbon fiber as a raw material The same as in Example 1.
-Step II: Step of attaching sizing agent to carbon fiber (A), (B1) Kinds and amounts of components, (C1), except that the amounts of other components were used as shown in Table 1-2. A carbon fiber coated 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 slightly low.

(Comparative Example 5)
-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) After preparing the aqueous solution of (A-2) as a component and applying it to the carbon fiber surface-treated by the dipping method, at a temperature of 210 ° C A carbon fiber coated with a sizing agent was obtained by heat treatment for 75 seconds. 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. 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 applied to the carbon fiber coated with the component (A) by the dipping method, and then heat-treated 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 be 0.30 parts by mass with respect to the finally obtained sizing agent-coated carbon fiber. 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: Step of attaching a sizing agent to carbon fiber The same procedure as in Example 1 was performed.
Step III: Step of producing long fiber pellets The impregnation aid (D-1) prepared in Reference Example 1 is melted in a 240 ° C. melting bath and supplied to the kiss coater with a gear pump. The impregnation aid (D-1) was applied from a kiss coater on a roll heated to 230 ° C. to form a film. A sizing agent-coated carbon fiber was passed through the roll while being in contact therewith, and a certain amount of impregnation aid (D-1) was adhered per unit length of the sizing agent-coated carbon fiber.
The sizing agent-coated carbon fibers to which the impregnation aid (D-1) is adhered are supplied into a furnace heated to 350 ° C., and freely rotate with bearings. Passing between rolls (φ50mm) and passing through 10 roll bars (φ200mm) installed in the furnace in a twisted manner, the impregnation aid (D-1) is sufficiently impregnated into the sizing agent coated carbon fiber The PAS was converted to a highly polymerized product. Next, air was blown onto the carbon fiber strand drawn from the furnace to cool it, and then wound with a drum winder. In addition, from the wound carbon fiber strand, 10 strands having a length of 10 mm were cut, and in order to separate the carbon fiber and the polyarylene sulfide, a Soxhlet extractor was used and 1-chloronaphthalene was used at 210 ° C. for 6 hours. Refluxing was performed for a time, and the extracted polyarylene sulfide was subjected to molecular weight measurement. The obtained PPS had a mass average molecular weight (Mw) of 26,800, a number average molecular weight (Mn) of 14,100, and a dispersity (Mw / Mn) of 1.90. Next, the mass reduction rate ΔWr of the extracted polyarylene sulfide was measured and found to be 0.09%. Moreover, the adhesion amount of the impregnation aid (D-1) was 20 parts by mass with respect to 100 parts by mass of the carbon fiber.

Subsequently, the PPS resin was melted at 360 ° C. in a single screw extruder, extruded into a crosshead die attached to the tip of the extruder, and simultaneously impregnated with a sizing agent (D-1). The fibers were also continuously fed into the crosshead die (speed: 30 m / min) to coat the melted PPS resin on the sizing agent-coated carbon fibers impregnated with the impregnation aid (D-1). Next, after cooling, the core-sheath structure is cut into 7 mm perpendicular to the drawing direction, the carbon fibers are arranged substantially parallel to the axial direction, and the length of the carbon fibers is substantially the same as the length of the molding material Long fiber pellets (form B) were obtained. The supply of the PPS resin pellets was adjusted so that the sizing agent-coated carbon fiber was 20% by mass with respect to the whole.
-Step IV: injection molding process Using the J350EIII type injection molding machine manufactured by Nippon Steel Works, the long fiber pellets obtained at the previous step were characterized at a cylinder temperature of 330 ° C and a mold temperature of 100 ° C. A test specimen for evaluation was molded. The obtained test piece was subjected to a characteristic evaluation test after being left in a constant temperature and humidity chamber adjusted to a temperature of 23 ° C. and 50% RH for 24 hours. 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 2. As a result, it was found that the bending strength was 282 MPa and the mechanical properties were sufficiently high.

(Examples 16 to 20)
-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 15 except that component (A) and component (B1) were changed as shown in Table 2 in step II of Example 15. 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 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 275 to 289 MPa, and the mechanical properties were sufficiently high.

(Comparative Example 6)
-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 1.
-Steps III to IV:
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)
-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 2.
-Steps III to IV:
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: Step of attaching a sizing agent to carbon fiber The same procedure as in Example 1 was performed.

Step III: Step of producing long fiber pellets A cross-head die processed into a wave shape that allows continuous sizing agent-coated carbon fibers to pass through was attached to the tip of a single screw extruder. Next, while drawing the continuous sizing agent-coated carbon fiber through the crosshead die at a speed of 5 m / min, the PC resin pellets are supplied from the extruder to the crosshead die in a molten state, and the continuous sizing agent-coated carbon fiber is supplied. PC resin is impregnated, the molten impregnated material is heated, cooled, cut to 7 mm perpendicular to the drawing direction, carbon fibers are arranged almost parallel to the axial direction, and the length of the carbon fibers is the molding material A long fiber pellet (form A) was obtained which was substantially the same as the length of. The extruder was sufficiently kneaded at a barrel temperature of 300 ° C. and a rotation speed of 150 rpm, and further deaerated from a downstream vacuum vent. The supply of the PC resin pellets was adjusted so that the sizing agent-coated carbon fiber was 20 parts by mass and the PC resin was 80 parts by mass.
-Step IV: injection molding process:
Using the J350EIII type injection molding machine manufactured by Nippon Steel Works, the long fiber pellets obtained in the previous step were molded into test pieces for characteristic evaluation at a cylinder temperature of 320 ° C. and a mold temperature of 70 ° C. The obtained test piece was subjected to a characteristic evaluation test after being left in a constant temperature and humidity chamber adjusted to a temperature of 23 ° C. and 50% RH for 24 hours. 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 3. As a result, it was found that the bending strength was 206 MPa and the mechanical properties were sufficiently high.

(Examples 22 to 26)
-Step I: Step of producing carbon fiber as a raw material The same as in Example 1.
-Step II: Step of attaching sizing agent to carbon fiber Example 21 except that (A) component and (B1) component were changed as shown in Table 3 in Step II of Example 21. 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 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 200 to 208 MPa, and the mechanical properties were sufficiently high.

(Comparative Example 8)
-Step I: Step of producing carbon fiber as a raw material The same as in Example 1.
-Step II: Step of attaching sizing agent to carbon fiber The same as Comparative Example 1.
-Steps III to IV:
A test piece for property 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 the bending strength was as shown in Table 3 and the mechanical properties were insufficient.

(Comparative Example 9)
-Step I: Step of producing carbon fiber as a raw material The same as in Example 1.
-Step II: Step of attaching sizing agent to carbon fiber The same as Comparative Example 2.
-Steps III to IV:
A test piece for property 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 the bending strength was as shown in Table 3 and the mechanical properties were slightly low.

(Example 27)
-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 fiber The same procedure as in Example 1 was performed.

Step III: Step of producing long fiber pellets The impregnation aid (D-2) is melted in a 190 ° C. melting bath and supplied to the kiss coater with a gear pump. An impregnation aid (D-2) was applied from a kiss coater on a roll heated to 180 ° C. to form a film. A sizing agent-coated carbon fiber was passed through the roll while being in contact therewith, and a certain amount of impregnation aid (D-2) was adhered per unit length of the sizing agent-coated carbon fiber. The sizing agent-coated carbon fibers to which the impregnation aid (D-2) is attached are supplied into a furnace heated to 180 ° C., and freely rotate with bearings. Pass between the rolls (φ50mm) and pass through 10 roll bars (φ200mm) installed in the furnace in a twisted manner (impregnation aid (D-2) is sufficiently applied to the sizing agent coated carbon fiber) The adhesion amount of the impregnation aid (D-2) was 20 parts by mass with respect to 100 parts by mass of the carbon fiber.

Subsequently, PP resin was melted at 240 ° C. with a single screw extruder, extruded into a crosshead die attached to the tip of the extruder, and simultaneously impregnated with a sizing agent (D-2). The fibers were also continuously fed into the crosshead die (speed: 30 m / min) to coat the sizing agent-coated carbon fibers impregnated with the melted PP resin with the impregnation aid (D-2). Next, after cooling, the core-sheath structure is cut into 7 mm perpendicular to the drawing direction, the carbon fibers are arranged substantially parallel to the axial direction, and the length of the carbon fibers is substantially the same as the length of the molding material Long fiber pellets (form B) were obtained. The supply of the PP resin pellets was adjusted so that the sizing agent-coated carbon fibers were 20% by mass with respect to the whole.
-Step IV: Injection molding process Using the J350EIII type injection molding machine manufactured by Nippon Steel Works, the long fiber pellets were obtained at a cylinder temperature of 240 ° C and a mold temperature of 60 ° C. A test specimen for evaluation was molded. The obtained test piece was subjected to a characteristic evaluation test after being left in a constant temperature and humidity chamber adjusted to a temperature of 23 ° C. and 50% RH for 24 hours. 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 4. As a result, it was found that the bending strength was 152 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 component (A) and component (B1) were changed as shown in Table 4 in step II of Example 27. 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 characteristic evaluation was formed 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 145 to 157 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 attaching sizing agent to carbon fiber The same as Comparative Example 1.
Steps III to IV Characteristic evaluation test pieces were formed 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 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 The same as Comparative Example 2.
-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 fiber The same procedure as in Example 1 was performed.

Step III: Step of producing long fiber pellets After adjusting the emulsion of the impregnation aid (D-3) to a solid content concentration of 27% by mass and adhering to the sizing agent-coated carbon fiber by the roller impregnation method, It dried at 210 degreeC for 2 minute (s), the water | moisture content was removed, and the composite_body | complex of sizing agent application | coating carbon fiber and 1st and 2nd propylene resin was obtained. The adhesion amount of the impregnation aid (D-3) was 20 parts by mass with respect to 100 parts by mass of the carbon fiber.
Subsequently, PP resin was melted at 300 ° C. with a single screw extruder and extruded into a crosshead die attached to the tip of the extruder, and at the same time, a sizing agent-coated carbon on which an impregnation aid (D-3) was adhered. The fibers were also continuously fed into the crosshead die (speed: 30 m / min) to coat the sizing agent-coated carbon fibers with the impregnation aid (D-3) adhered thereto with the melted PP resin. Next, after cooling, the core-sheath structure is cut into 7 mm perpendicular to the drawing direction, the carbon fibers are arranged substantially parallel to the axial direction, and the length of the carbon fibers is substantially the same as the length of the molding material Long fiber pellets (form B) were obtained. The supply of the PP resin pellets was adjusted so that the sizing agent-coated carbon fibers were 20% by mass with respect to the whole.
-Step IV: Injection molding process Using the J350EIII type injection molding machine manufactured by Nippon Steel Works, the long fiber pellets were obtained at a cylinder temperature of 240 ° C and a mold temperature of 60 ° C. A test specimen for evaluation was molded. The obtained test piece was subjected to a characteristic evaluation test after being left in a constant temperature and humidity chamber adjusted to a temperature of 23 ° C. and 50% RH for 24 hours. 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 5. As a result, it was found that the bending strength was 152 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 (B1) 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 characteristic evaluation was formed 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 146 to 158 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 1.
Steps III to IV Characteristic evaluation test pieces were formed 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. 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 2.
Steps III to IV Characteristic evaluation test pieces were formed 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)
-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 fiber The same procedure as in Example 1 was performed.

Step III: Step of producing long fiber pellets The impregnation aid (D-4) is melted in a 190 ° C. melting bath and supplied to the kiss coater with a gear pump. The impregnation aid (D-4) was applied from a kiss coater on a roll heated to 180 ° C. to form a coating. A sizing agent-coated carbon fiber was passed through the roll while being in contact therewith, and a certain amount of impregnation aid (D-4) was adhered per unit length of the sizing agent-coated carbon fiber. The sizing agent-coated carbon fibers to which the impregnation aid (D-4) is attached are fed into a furnace heated to 180 ° C. and freely rotated by bearings. Passing between rolls (φ50mm) and passing through 10 roll bars (φ200mm) installed in the furnace in a twisted manner, the impregnation aid (D-4) is sufficiently impregnated with sizing agent coated carbon fiber I let you. The adhesion amount of the impregnation aid (D-4) was 20 parts by mass with respect to 100 parts by mass of the carbon fiber.

Subsequently, PA6 resin was melted at 300 ° C. in a single screw extruder, extruded into a crosshead die attached to the tip of the extruder, and simultaneously impregnated with a sizing agent (D-4). The fibers were also continuously fed into the crosshead die (speed: 30 m / min) to coat the melted PA6 resin on the sizing agent-coated carbon fibers impregnated with the impregnation aid (D-4). Next, after cooling, the core-sheath structure is cut into 7 mm perpendicular to the drawing direction, the carbon fibers are arranged substantially parallel to the axial direction, and the length of the carbon fibers is substantially the same as the length of the molding material Long fiber pellets (form B) were obtained. The supply of PA6 resin pellets was adjusted so that the sizing agent-coated carbon fiber was 30% by mass with respect to the whole.
-Step IV: injection molding process:
Using the J350EIII type injection molding machine manufactured by Nippon Steel Works, the long fiber pellets obtained in the previous step were molded into test pieces for characteristic evaluation at a cylinder temperature of 300 ° C. and a mold temperature of 70 ° C. The obtained test piece was subjected to a characteristic evaluation test after being left in a constant temperature and humidity chamber adjusted to a temperature of 23 ° C. and 50% RH for 24 hours. 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 6. As a result, it was found that the bending strength was 362 MPa and the mechanical properties were sufficiently high.

(Examples 40 to 44)
-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 39, except that component (A) and component (B1) were changed as shown in Table 6 in step II of Example 39. 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 characteristic evaluation was formed in the same manner as in Example 39. 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 6. As a result, it was found that the bending strength was 365 to 368 MPa, and the mechanical properties were sufficiently high.

(Comparative 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 The same as Comparative Example 1.
Steps III to IV Characteristic evaluation test pieces were formed in the same manner as in Example 39. 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 6 and the mechanical properties were insufficient.

(Comparative Example 15)
-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 2.
Steps III to IV Characteristic evaluation test pieces were formed in the same manner as in Example 39. 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 6 and the mechanical properties were slightly low.

(Example 45)
2 g of the sizing agent-coated carbon fiber 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. Table 7 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 7.

(Examples 46 to 47)
(A) CHx of the C1s inner shell spectrum by X-ray photoelectron spectroscopy using 400 eV X-rays before and after washing using the sizing agent-coated carbon fibers obtained in Example 2 and Example 3 as in Example 45 , 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 7.

(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 1 as in Example 45. , 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 7, and it was found that (II / I) was large and no grading structure was obtained in the sizing agent.

(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 washing using the sizing agent-coated carbon fiber obtained in Comparative Example 2 as in Example 45 , 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 7, 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 5 as in Example 45 , 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 7, and it was found that (II / I) was small.

(Example 48)
10 g of the molding material obtained in Example 21 was placed in a cylindrical filter paper, and Soxhlet extraction was performed using 300 ml of dichloromethane to elute the thermoplastic resin and the sizing agent. Thereafter, the solvent was dried by drying at 80 ° C. for 30 minutes. Table 8 shows the amount of sizing agent adhering to the carbon fibers remaining after washing.
(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 calculated, and (a) / (b) was calculated. Table 8 shows (a) / (b).

(Example 49)
The X-ray photoelectron spectroscopy at 400 eV on the sizing agent surface of the sizing agent-coated carbon fiber obtained by washing in the same manner as in Example 48 using the molding material obtained in Example 23 was converted to Determine the peak height of the assigned 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 (a) / (b ) The amount of sizing agent remaining and (a) / (b) remaining after washing was as shown in Table 8.

(Example 50)
10 g of the molding material obtained in Example 39 was put into 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 was as shown in Table 8.

(Example 51)
The sizing agent-coated carbon fiber obtained by washing in the same manner as in Example 50 using the molding material obtained in Example 41 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. The amount of sizing agent remaining and (a) / (b) remaining after washing was as shown in Table 8.

(Comparative Example 19)
The X-ray photoelectron spectroscopy at 400 eV on the surface of the sizing agent-coated carbon fiber obtained by washing in the same manner as in Example 48 using the molding material obtained in Comparative Example 8 was converted into (b) CO component. Determine the peak height of the assigned 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 (a) / (b ) As shown in Table 8, the sizing agent adhesion amount and (a) / (b) remaining after washing were large values.

(Comparative Example 20)
The X-ray photoelectron spectroscopy at 400 eV on the sizing agent surface of the sizing agent-coated carbon fiber obtained by washing in the same manner as in Example 48 using the molding material obtained in Comparative Example 9 was converted into (b) CO component. Determine the peak height of the assigned 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 (a) / (b ) As shown in Table 8, the sizing agent adhesion amount and (a) / (b) remaining after washing were small values.

(Comparative Example 21)
Sizing agent-coated carbon fiber obtained by washing in the same manner as in Example 50 using the molding material obtained in Comparative Example 14 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 8, the sizing agent adhesion amount and (a) / (b) remaining after washing were large values.

(Comparative Example 22)
Sizing agent-coated carbon fiber obtained by washing in the same manner as in Example 50 using the molding material obtained in Comparative Example 15 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. As shown in Table 8, 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.

1, 1A molding material 2 carbon fiber 3 thermoplastic resin 4 impregnation aid

Claims (21)

A sizing agent-coated carbon fiber obtained by applying a sizing agent to carbon fiber, and a columnar molding material composed of a thermoplastic resin,
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 0. 50-0.90,
The molding material, wherein the carbon fibers in the molding material are arranged substantially parallel to the axial direction, and the length of the carbon fibers in the molding material is substantially the same as the length of the molding material.   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 subjected to ultrasonic treatment in a solvent that dissolves the thermoplastic 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 sizing agent-coated carbon fiber that has been cleaned up to (a) CHx, C-C, C1s inner-shell spectrum 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 C = C and the height (cps) of the component (b) of the bond energy (286.1 eV) attributed to CO The molding material according to claim 1, wherein the ratio (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.   Sizing agent application | coating carbon fiber in which the said sizing agent adheres 0.1-10.0 mass parts with respect to 100 mass parts of said carbon fibers, and 20-99 mass% of thermoplastic resins are included. The molding material as described in any one of Claims 1-10 characterized by the above-mentioned.   The structure Y mainly composed of the carbon fiber coated with the sizing agent is a core structure, the structure X mainly composed of the thermoplastic resin is a sheath structure, and the structure X covers the periphery of the structure Y with the core X It has a structure, The molding material as described in any one of Claims 1-11 characterized by the above-mentioned.   The molding material according to claim 1, wherein a length of the columnar molding material is 1 to 50 mm.   The molding material according to any one of claims 1 to 13, wherein the form is a long fiber pellet.   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 any one of claims 1 to 14.   The molding material according to claim 1, wherein the thermoplastic resin is polyamide.   The molding material according to claim 1, comprising 0.1 to 100 parts by mass of the impregnation aid (D) with respect to 100 parts by mass of the carbon fiber.   The molding material according to claim 17, wherein a part or all of the impregnation aid (D) is impregnated in carbon fiber. A method for producing a molding material for producing the molding material according to any one of claims 1 to 18, comprising:
Application in which continuous carbon fiber is coated with 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) based on the total amount of the sizing agent excluding the solvent Process,
A continuous sizing agent-coated carbon fiber obtained in the coating step with a molten thermoplastic resin, and a stranding step to obtain a continuous strand;
After cooling the strand obtained in the stranding step, cutting step to obtain a columnar molding material by cutting,
The manufacturing method of the molding material characterized by including.   The method for producing a molding material according to claim 19, further comprising an impregnation step of impregnating the continuous sizing agent-coated carbon fibers with the melted impregnation aid (D) before the stranding step.   A carbon fiber reinforced composite material obtained by molding the molding material according to any one of claims 1 to 18 or the molding material produced by the method according to claim 19 or 20.

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