Abstract: A method of manufacturing a prepreg. The method includes step (I) of dispersing a reinforcing fiber bundle to obtain a reinforcing fiber base material, step (II) of providing a binder to the reinforcing fiber base material produced in the step (I), and step (III) of hybridizing a matrix resin composed of a thermoplastic resin with the reinforcing fiber base material provided with the binder produced in the step (II), wherein the steps (I) to (II) are carried out online and the prepreg is one such that the content of the reinforcing fiber bundle relative to the whole portion of the prepreg is from 10 to 80% by mass, the content of the binder relative to the whole portion of the prepreg is from 0.1 to 10% by mass, and the content of the matrix resin relative to the whole portion of the prepreg is from 10 to 80% by mass.

Abstract: This invention is A prepreg comprising a reinforcing fiber base material impregnated with a thermoplastic resin, wherein the reinforcing fiber base material comprises from 0 to 50% by mass of reinforcing fibers each having a fiber length of more than 10 mm, from 50 to 100% by mass of reinforcing fibers each having a fiber length of from 2 to 10 mm, and from 0 to 50% by mass of reinforcing fibers each having a fiber length of less than 2 mm, the average of two-dimensional orientation angles each formed by a reinforcing filament (a) and a reinforcing filament (b) intersecting the reinforcing filament (a) is from 10 to 80°, the thickness h0 (mm) at 23° C. is 0.03 to 1 mm, and the tensile strength ? is 0.01 MPa or more. The prepreg can be applied for thin molded products which have been considered unsuitable as a laminated molded product and can provide molded products that have a complicated shape and have isotropically high mechanical properties.

Abstract: This invention is A prepreg comprising a reinforcing fiber base material impregnated with a thermoplastic resin, wherein the reinforcing fiber base material comprises from 0 to 50% by mass of reinforcing fibers each having a fiber length of more than 10 mm, from 50 to 100% by mass of reinforcing fibers each having a fiber length of from 2 to 10 mm, and from 0 to 50% by mass of reinforcing fibers each having a fiber length of less than 2 mm, the average of two-dimensional orientation angles each formed by a reinforcing filament (a) and a reinforcing filament (b) intersecting the reinforcing filament (a) is from 10 to 80°, the thickness h0 (mm) at 23° C. is 0.03 to 1 mm, and the tensile strength ? is 0.01 MPa or more. The prepreg can be applied for thin molded products which have been considered unsuitable as a laminated molded product and can provide molded products that have a complicated shape and have isotropically high mechanical properties.

Abstract: Water dispersible carbon fibers, (1) wherein the surface oxygen concentration (O/C) of each of the single fibers is 0.03 or more and less than 0.12 as measured by X-ray photoelectron spectroscopy and forming a first contact angle with water of 75° or less as measured by the Wilhelmy method; (2) wherein the O/C is 0.12 or more and less than 0.20 and forming a first contact angle with water of 65° or less as measured by the Wilhelmy method; or (3) wherein the O/C is 0.20 or more and 0.30 or less and forming a first contact angle with water of 55° or less as measured by the Wilhelmy method; and wherein a sizing agent containing a surfactant as a major component has adhered to the single fibers of each of the water dispersible carbon fibers.

Abstract: According to the present invention, a fiber-reinforced thermoplastic resin molded article in which monofilamentous carbon fibers are contained in a thermoplastic resin in a high content, such fibers having long fiber lengths and being randomly arranged, is provided. Also, a molding material comprising monofilamentous carbon fibers and monofilamentous thermoplastic resin fibers, in which the carbon fibers are contained in a high content, such fibers having long fiber lengths and being randomly arranged, is provided. In addition, a method for producing a fiber-reinforced thermoplastic resin molded article, comprising molding the molding material by compression molding, is provided.

Abstract: According to the present invention, a fiber-reinforced thermoplastic resin molded article in which monofilamentous carbon fibers are contained in a thermoplastic resin in a high content, such fibers having long fiber lengths and being randomly arranged, is provided. Also, a molding material comprising monofilamentous carbon fibers and monofilamentous thermoplastic resin fibers, in which the carbon fibers are contained in a high content, such fibers having long fiber lengths and being randomly arranged, is provided. In addition, a method for producing a fiber-reinforced thermoplastic resin molded article, comprising molding the molding material by compression molding, is provided.

Abstract: This invention is an impact energy absorption device, in which a long part (1) made of a high strength material is disposed with its lengthwise direction kept different from an impact direction, and both terminals of the long part (1) are connected with columns (2) through upper platens (3) covering the upper faces of the columns (2) kept standing apart from each other with a predetermined distance (L), comprising a structural system, in which a deformation of the long part (1) caused by the impact force applied to it, causes the upper platens (3) to move for compressing or deflecting the columns (2), thereby absorbing the impact energy. The conventional column type energy absorption member is weak against an impact applied in a direction within a wide angle (?) such as an impact applied in an oblique direction.

Abstract: Water dispersible carbon fibers, (1) wherein the surface oxygen concentration (O/C) of each of the single fibers is 0.03 or more and less than 0.12 as measured by X-ray photoelectron spectroscopy and forming a first contact angle with water of 75° or less as measured by the Wilhelmy method; (2) wherein the O/C is 0.12 or more and less than 0.20 and forming a first contact angle with water of 65° or less as measured by the Wilhelmy method; or (3) wherein the O/C is 0.20 or more and 0.30 or less and forming a first contact angle with water of 55° or less as measured by the Wilhelmy method; and wherein a sizing agent containing a surfactant as a major component has adhered to the single fibers of each of the water dispersible carbon fibers.

Abstract: A light-weight, highly rigid, high-strength environment-friendly fiber-reinforced plastic (hereinafter, CFRP) board having a surface quality that can endure long-term use suitable for use in automobiles and the like is provided. A method for making the same is also provided. The CFRP board includes a board member formed from a woven fabric as a reinforcing base material, the woven fabric including carbon fibers; and at least one of a gel coat and a paint provided on the board member, wherein the NSIC value of the surface of the CFRP board is 30% or more.

Abstract: The present invention relates: to an epoxy resin composition comprising at least (A) an epoxy resin having a cycloalkane ring or cyclohexene ring but having neither aromatic ring nor aminic nitrogen atom, (B) a carboxylic anhydride having no aromatic ring, and (C) an ultraviolet absorbent, wherein a content of component (A) is from 70 to 100 percents by weight based on the total weight of epoxy resins, and a content of component (B) is from 70 to 100 percents by weight based on the total weight of carboxylic anhydrides. By this constitution, the present invention can provide an epoxy resin composition whose cured product excels in mechanical properties and weatherability, and a fiber reinforced composite material having excellent mechanical properties and weatherability.

Abstract: The present invention relates to an epoxy resin composition comprising at least (A) an epoxy resin having a cycloalkane ring or cyclohexene ring but having neither aromatic ring nor aminic nitrogen atom, (B) a carboxylic anhydride having no aromatic ring, and (C) an ultraviolet absorbent, wherein a content of component (A) is from 70 to 100 percents by weight based on the total weight of epoxy resins, and a content of component (B) is from 70 to 100 percents by weight based on the total weight of carboxylic anhydrides. By this constitution, the present invention can provide an epoxy resin composition whose cured product excels in mechanical properties and weatherability, and a fiber reinforced composite material having excellent mechanical properties and weatherability.

Abstract: A light-weight, highly rigid, high-strength environment-friendly fiber-reforced plastic (hereinafter, CFRP) board having a surface quality that can endure long-term use suitable for use in automobiles and the like is provided. A method for making the same is also provided.

Abstract: This invention is an impact energy absorption device, in which a long part (1) made of a high strength material is disposed with its lengthwise direction kept different from an impact direction, and both terminals of the long part (1) are connected with columns (2) through upper platens (3) covering the upper faces of the columns (2) kept standing apart from each other with a predetermined distance (L), comprising a structural system, in which a deformation of the long part (1) caused by the impact force applied to it, causes the upper platens (3) to move for compressing or deflecting the columns (2), thereby absorbing the impact energy.

Abstract: The present invention relates to an epoxy resin composition comprising at least (A) an epoxy resin having a cycloalkane ring or cyclohexene ring but having neither aromatic ring nor aminic nitrogen atom, (B) a carboxylic anhydride having no aromatic ring, and (C) an ultraviolet absorbent, wherein a content of component (A) is from 70 to 100 percents by weight based on the total weight of epoxy resins, and a content of component (B) is from 70 to 100 percents by weight based on the total weight of carboxylic anhydrides.