Abstract: A laminate includes a core obtained by impregnating a mat of fibers with a thermoplastic resin (B); and a skin obtained by impregnating continuous fiber(s) with a thermoplastic resin (A), wherein sheet-form intermediate substrates in the laminate have a thermal expansibility, the usable temperature region of said thermoplastic resin (A) and that of said thermoplastic resin (B) overlap over a temperature range of at least 5° C., said thermoplastic resin (A) has a temperature region that does not melt at a lower limit of said usable temperature region, said fibers contained in said mat penetrate through interface layers formed by said thermoplastic resin (A) and said thermoplastic resin (B), and said thermoplastic resin (A) and said thermoplastic resin (B) form interface layers each with a concave-convex shape having a maximum height Ry of not less than 50 ?m and an average roughness Rz of not less than 30 ?m.

Abstract: The purpose of the present invention is to provide: an epoxy resin composition capable of giving cured resins which combine flexural modulus with flexural strain on a high level and have excellent heat resistance; a prepreg comprising the epoxy resin composition and reinforcing fibers; and a fiber-reinforced composite material obtained by curing the prepreg and excellent especially in terms of 0° and 90° bending strength. An embodiment of the epoxy resin composition of the present invention for achieving such purpose is an epoxy resin composition which comprises the following components [A], [B], and [C] and satisfies a specific requirement. Component [A]: a trifunctional amine type epoxy resin. Component [B]: a bisphenol F type epoxy resin which is solid at 25° C. Component [C]: an aromatic amine compound.

Abstract: An object of the present invention is to provide a prepreg and a laminate for producing a laminate suitable as a structural material, which have excellent compressive strength and interlaminar fractural toughness values, and can be firmly integrated with another structural member by welding. The present invention provides a prepreg including the following structural components [A] reinforcing fibers, [B] a thermosetting resin, and [C] a thermoplastic resin, in which [B] has a rubbery state elastic modulus of 10 MPa or more at a temperature obtained by adding 50° C. to a glass transition temperature in a state in which a degree of cure is 90% or more, [C] is present in a surface of the prepreg, and the reinforcing fibers [A] are present, which are included in a resin area including {B] and a resin area including [C] across an interface between the two resin areas.

Abstract: An epoxy resin composition is provided that has an elastic modulus, deformability, fracture toughness, and heat resistance in good balance. A prepreg produced from the epoxy resin composition and a fiber-reinforced composite material produced by curing the prepreg are also provided, where the epoxy resin composition includes the components [A], [B], and [C] and satisfies all of the requirements (1), (2), and (3) as described.

Abstract: An object of the present invention is to provide a prepreg and a laminate for producing a laminate suitable as a structural material, which have excellent compressive strength and interlaminar fractural toughness values, and can be firmly integrated with another structural member by welding. The present invention provides a prepreg including the following structural components [A] reinforcing fibers, [B] a thermosetting resin, and [C] a thermoplastic resin, in which [B] has a rubbery state elastic modulus of 10 MPa or more at a temperature obtained by adding 50° C. to a glass transition temperature in a state in which a degree of cure is 90% or more, [C] is present in a surface of the prepreg, and the reinforcing fibers [A] are present, which are included in a resin area including {B] and a resin area including [C] across an interface between the two resin areas.

Abstract: An object of the present invention is to provide a prepreg and a laminate for producing a laminate suitable as a structural material, which have excellent joining strength and interlaminar fractural toughness values and can be firmly integrated with another structural member by welding. The present invention provides a prepreg including the following structural components, [A] reinforcing fibers, [B] an epoxy resin, and [C] a thermoplastic resin, wherein all epoxy resins included in [B] have an average epoxy value of 2.0 meq./g or more and 5.0 meq./g or less, [C] is present in a surface of the prepreg, and the reinforcing fibers [A] are present, which are included in a resin area including [B] and a resin area including [C] across an interface between the two resin areas.

Abstract: The purpose of the present invention is to provide an epoxy resin composition which exhibits a high level of deforming capacity and fracture toughness and from which a resin cured product maintaining heat resistance can be obtained. The epoxy resin composition according to the present invention satisfies condition 1 or condition 2 below, wherein the resin cured product obtained by reacting the epoxy resin composition at 150° C. for 60 minutes has a tensile elongation at break of 7% or more. Condition 1: including all the following components [A], [B], and [C], component [A]: a bifunctional aliphatic epoxy resin having a specific structure, component [B]: a terminal carboxy-modified acrylic rubber, and component [C]: a dicyandiamide.

Abstract: The present invention aims to provide an epoxy resin composition that is high in both fast curability and storage stability, a prepreg prepared by using the epoxy resin composition, and a fiber reinforced composite material prepared by curing the prepreg. The epoxy resin composition contains the following components [A], [B], [C], and [D] and meets the following requirements [a], [b], and [c]: [A]: epoxy resin, [B]: dicyandiamide, [C]: aromatic urea, [D]: borate ester, [a]: 0.014?(content of component [D]/content of component [C])?0.045, [b]: 0.9?(number of moles of active groups in component [A]/number of moles of active hydrogen in component [B])?1.2, and [c]: 14?(content of component [A]/content of component [C])?25.

Abstract: One purpose of the present invention is to provide an epoxy resin composition which is for obtaining a fiber-reinforced composite material that combines heat resistance with tensile strength on a high level. The other purpose is to provide: a fiber-reinforced composite material obtained using this epoxy resin composition; and a molded article and a pressure vessel both containing the fiber-reinforced composite material. The present invention has the following configuration in order to achieve the above purposes. Namely, the epoxy resin composition includes the constituent element [A]: An epoxy resin including an aromatic ring and having a functionality of 2 or higher and the following constituent element [B]: An acid anhydride-based hardener, and is characterized in that a cured object obtained by curing the epoxy resin composition has a rubber-state modulus of 10 MPa or less when evaluated for dynamic viscoelasticity and the cured object has a glass transition temperature of 95° C. or higher.

Abstract: One purpose of the present invention is to provide an epoxy resin composition which is for obtaining a fiber-reinforced composite material that combines heat resistance with tensile strength on a high level. Another purpose is to provide: a fiber-reinforced composite material obtained using this epoxy resin composition; and a molded article and a pressure vessel both containing the fiber-reinforced composite material. The present invention has the following configuration in order to achieve the above purposes. Namely, the epoxy resin composition includes the constituent element [A]: An epoxy resin including an aromatic ring and having a functionality of 2 or higher and the following constituent element [B]: An amine-based hardener, and is characterized in that a cured object obtained by curing the epoxy resin composition has a rubber-state modulus of 10 MPa or less when evaluated for dynamic viscoelasticity and the cured object has a glass transition temperature of 95° C. or higher.

Abstract: The present invention provides an epoxy resin composition that serves to produce a cured epoxy resin that simultaneously realizes a high heat resistance, a high elastic modulus, and a low color and to produce a molded article having a good appearance without suffering the formation of white spots on the surface thereof when used as matrix resin in a fiber reinforced composite material. The epoxy resin composition includes an epoxy resin as component [A], an aromatic urea [B1] and/or an imidazole compound [B2] as component [B], and a borate ester compound as component [C], containing dicyandiamide in the amount of 0.5 part by mass or less relative to the total quantity of epoxy resins which accounts for 100 parts by mass, wherein the epoxy resin composition meets certain sets of further requirements with respect to its composition.

Abstract: A laminate includes a core obtained by impregnating a mat of fibers with a thermoplastic resin (B); and a skin obtained by impregnating continuous fiber(s) with a thermoplastic resin (A), wherein sheet-form intermediate substrates in the laminate have a thermal expansibility, the usable temperature region of said thermoplastic resin (A) and that of said thermoplastic resin (B) overlap over a temperature range of at least 5° C., said thermoplastic resin (A) has a temperature region that does not melt at a lower limit of said usable temperature region, said fibers contained in said mat penetrate through interface layers formed by said thermoplastic resin (A) and said thermoplastic resin (B), and said thermoplastic resin (A) and said thermoplastic resin (B) form interface layers each with a concave-convex shape having a maximum height Ry of not less than 50 ?m and an average roughness Rz of not less than 30 ?m.

Abstract: The purpose of the present invention is to provide: an epoxy resin composition capable of giving cured resins which combine flexural modulus with flexural strain on a high level and have excellent heat resistance; a prepreg comprising the epoxy resin composition and reinforcing fibers; and a fiber-reinforced composite material obtained by curing the prepreg and excellent especially in terms of 0° and 90° bending strength. An embodiment of the epoxy resin composition of the present invention for achieving such purpose is an epoxy resin composition which comprises the following components [A], [B], and [C] and satisfies a specific requirement. Component [A]: a trifunctional amine type epoxy resin. Component [B]: a bisphenol F type epoxy resin which is solid at 25° C. Component [C]: an aromatic amine compound.

Abstract: A sandwich laminate, includes as a layer forming a core, a sheet-form intermediate substrate obtained by impregnating a mat composed of reinforcement fibers with a thermoplastic resin; and, as layers forming a skin, sheet-form intermediate substrates obtained by impregnating a mat composed of reinforcement fibers or continuous reinforcement fibers with a thermoplastic resin, wherein at least the sheet-form intermediate substrate used as the layer forming a core has a thermal expansibility, the usable temperature region of a thermoplastic resin (A) constituting the layers forming a skin and that of a thermoplastic resin (B) constituting the layer forming a core overlap each other over a temperature range of at least 5° C., and the thermoplastic resin (A) has a temperature region where it does not melt at a lower limit of the usable temperature region of the thermoplastic resin (B).

Abstract: An epoxy resin composition comprises components [A] to [C]. The component [C] is a component [c1] or [c2] and the rubbery state elastic modulus of a cured article produced by curing the epoxy resin composition in a dynamic viscoelasticity evaluation is 10 MPa or less. Component[A] is a phenyl glycidyl ether substituted by a tert-butyl group, a sec-butyl group, an isopropyl group or a phenyl group. Component [B] is a bifunctional or higher aromatic epoxy resin. Component [C] is a curing agent selected from component [c1], which is an acid anhydride-type curing agent and component [c2], which is an aliphatic amine-type curing agent.

Abstract: The present invention provides an epoxy resin composition that serves to produce a cured epoxy resin that simultaneously realizes a high heat resistance, a high elastic modulus, and a low color and to produce a molded article having a good appearance without suffering the formation of white spots on the surface thereof when used as matrix resin in a fiber reinforced composite material. The epoxy resin composition includes an epoxy resin as component [A] and an imidazole compound as component [B] and meets certain conditions (a) to (d).

Abstract: A method of producing a fiber reinforced composite material satisfies condition 1: a thermosetting resin base material (B) includes a thermosetting resin (a) and a nonwoven fabric-shaped base material (a thermosetting resin base material satisfying the condition 1 is referred to as a thermosetting resin base material (B-1)); and condition 2: the thermosetting resin base material (B) is a base material including the thermosetting resin (a), and a porous sheet-shaped base material (b) or a film-shaped base material (c), the thermosetting resin (a) has a viscosity of 1,000 Pa·s or more at 40° C., and the thermosetting resin (a) has a minimum viscosity of 10 Pa·s or less during heating from 30° C. at a temperature rise rate of 1.5° C./min (a thermosetting resin base material satisfying the condition 2 is referred to as a thermosetting resin base material (B-2)).

Abstract: There is provided a cured product of an epoxy resin composition, in which the compounding composition and the phase-separated structure of the epoxy resin composition are controlled so that the balance between rigidity and toughness of the cured product is superior compared with those of cured products of conventional epoxy resin compositions. A cured product of an epoxy resin composition, which has both superior rigidity and superior toughness compared with conventional materials can be produced by curing an epoxy resin composition comprising an epoxy resin, a polyrotaxane having graft-chain-modified cyclic molecules and a curing agent for the epoxy resin.

Abstract: One purpose of the present invention is to provide an epoxy resin composition which is for obtaining a fiber-reinforced composite material that combines heat resistance with tensile strength on a high level. Another purpose is to provide: a fiber-reinforced composite material obtained using this epoxy resin composition; and a molded article and a pressure vessel both containing the fiber-reinforced composite material. The present invention has the following configuration in order to achieve the above purposes. Namely, the epoxy resin composition includes the constituent element [A]: An epoxy resin including an aromatic ring and having a functionality of 2 or higher and the following constituent element [B]: An amine-based hardener, and is characterized in that a cured object obtained by curing the epoxy resin composition has a rubber-state modulus of 10 MPa or less when evaluated for dynamic viscoelasticity and the cured object has a glass transition temperature of 95° C. or higher.

Abstract: One purpose of the present invention is to provide an epoxy resin composition which is for obtaining a fiber-reinforced composite material that combines heat resistance with tensile strength on a high level. The other purpose is to provide: a fiber-reinforced composite material obtained using this epoxy resin composition; and a molded article and a pressure vessel both containing the fiber-reinforced composite material. The present invention has the following configuration in order to achieve the above purposes. Namely, the epoxy resin composition includes the constituent element [A]: An epoxy resin including an aromatic ring and having a functionality of 2 or higher and the following constituent element [B]: An acid anhydride-based hardener, and is characterized in that a cured object obtained by curing the epoxy resin composition has a rubber-state modulus of 10 MPa or less when evaluated for dynamic viscoelasticity and the cured object has a glass transition temperature of 95° C. or higher.